Who is the manufacturer of Wondfo 2019-nCoV Antigen Test (Lateral Flow Method)?

Guangzhou Wondfo Biotech Co., Ltd. filed the 510(k) submission for Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) (K241317).

What is the FDA product code for Wondfo 2019-nCoV Antigen Test (Lateral Flow Method)?

QYT. It is classified under 21 CFR 866.3984 as a Class 2 device in the Microbiology panel.

What is the regulatory pathway for Wondfo 2019-nCoV Antigen Test (Lateral Flow Method)?

510(k) clearance (submission type: Traditional).

Who can help prepare an FDA 510(k) submission like Wondfo 2019-nCoV Antigen Test (Lateral Flow Method)?

Innolitics — a medical-device software consultancy — provides regulatory and engineering support for FDA 510(k) submissions. See https://innolitics.com/services/510ks/ or contact https://innolitics.com/contact.

Wondfo 2019-nCoV Antigen Test (Lateral Flow Method)

Q: What are the predicate devices for Wondfo 2019-nCoV Antigen Test (Lateral Flow Method)?

Flowflex COVID-19 Antigen Home Test (K230828).

K241317 · Guangzhou Wondfo Biotech Co., Ltd. · QYT · Sep 30, 2024 · Microbiology

Device Facts

Record ID	K241317
Device Name	Wondfo 2019-nCoV Antigen Test (Lateral Flow Method)
Applicant	Guangzhou Wondfo Biotech Co., Ltd.
Product Code	QYT · Microbiology
Decision Date	Sep 30, 2024
Decision	SESE
Submission Type	Traditional
Regulation	21 CFR 866.3984
Device Class	Class 2
Attributes	Pediatric

Intended Use

The Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) is a visually read lateral flow immunoassay test intended for the qualitative detection of SARS-CoV-2 virus nucleocapsid protein antigen directly in anterior nasal swab specimens from individuals with signs and symptoms of COVID-19. This test is for non-prescription home use by individuals aged 14 years or older testing themselves, or adults testing individuals aged 2 years or older. All negative results are presumptive. Symptomatic individuals with an initial negative test result must be re-tested once between 48 and 72 hours after the first test using either an antigen test or a molecular test for SARS-CoV-2. Negative results do not rule out SARS-CoV-2 infections or other pathogens and should not be used as the sole basis for treatment. Positive results do not rule out co-infection with other respiratory pathogens. This test is not a substitute for visits to a healthcare provider or appropriate follow-up and should not be used to determine any treatments without provider supervision. Individuals who test negative and experience continued or worsening COVID-19 like symptoms, such as fever, cough and/or shortness of breath, should seek follow up care from their healthcare provider. The performance characteristics for SARS-CoV-2 were established from April, 2023 to February, 2024 when SARS-CoV-2 Omicron was dominant. Test accuracy may change as new SARS-CoV-2 viruses emerge. Additional testing with a lab-based molecular test (e.g., PCR) should be considered in situations where a new virus or variant is suspected.

Device Story

Lateral flow immunoassay for qualitative detection of SARS-CoV-2 nucleocapsid protein antigen; utilizes anterior nasal swab samples. User collects sample; inserts into pre-filled extraction buffer tube to disrupt virus; adds extracted specimen to test cassette sample well. Specimen migrates via capillary action across nitrocellulose membrane; SARS-CoV-2 antigens bind to dye-conjugated antibodies; sandwich complexes captured at test line (T) by immobilized antibodies; control line (C) indicates valid flow. Visually read by user 10-20 minutes post-application. Home-use device; intended for symptomatic individuals. Negative results are presumptive; requires serial testing (re-test 48-72 hours later) to mitigate false negatives. Provides rapid identification of SARS-CoV-2; supports clinical decision-making regarding isolation and follow-up care.

Clinical Evidence

Prospective lay-person clinical study (n=1,032 evaluable subjects) conducted April 2023–February 2024. Compared candidate test to 510(k)-cleared RT-PCR assay. Results: PPA 84.38% (95% CI: 77.10%–89.65%); NPA 99.67% (95% CI: 99.03%–99.89%). Usability study (n=30) confirmed lay-user ability to perform critical tasks. Readability/comprehension study (n=50) showed high accuracy in interpreting mock test results.

Technological Characteristics

Lateral flow immunoassay; nitrocellulose membrane with test (T) and control (C) lines; dye-conjugated antibody technology. Components: test cassette, extraction buffer tube, swab, tube holder. Storage: 2°C to 30°C. Visual readout. No electronic components or software.

Indications for Use

Indicated for qualitative detection of SARS-CoV-2 nucleocapsid protein antigen in anterior nasal swab specimens from symptomatic individuals. For non-prescription home use by individuals aged 14+ testing themselves, or adults testing individuals aged 2+.

Regulatory Classification

Identification

For the rapid, qualitative detection of SARS-CoV-2 virus nucleocapsid protein antigen in individuals 2 years and older.

Predicate Devices

Flowflex COVID-19 Antigen Home Test (K230828)

Related Devices

K240728 — CorDx Tyfast COVID-19 Ag Rapid Test; CorDx COVID-19 Ag Test · CorDx, Inc. · Jun 21, 2024
K251289 — WELLlife COVID-19 Antigen Test Rx · Guangzhou Wondfo Biotech Co., Ltd. · Oct 22, 2025
K251595 — COVID-19 Detect Rapid Self -Test · InBios International, Inc. · Oct 12, 2025

Submission Summary (Full Text)

{0}------------------------------------------------ September 30, 2024 Image /page/0/Picture/1 description: The image contains the logo of the U.S. Food and Drug Administration (FDA). On the left, there is a seal with the words "DEPARTMENT OF HEALTH & HUMAN SERVICES - USA". To the right of the seal, there is a blue square with the letters "FDA" in white. Next to the blue square, the words "U.S. FOOD & DRUG ADMINISTRATION" are written in blue. Guangzhou Wondfo Biotech Co., Ltd. Xiao Kaiyu Regulatory Affairs Manager No.8 Lizhishan Road, Science City, Huangpu District Guangzhou, 510663 China Re: K241317 Trade/Device Name: Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) Regulation Number: 21 CFR 866.3984 Regulation Name: Over-The-Counter Test To Detect SARS-Cov-2 From Clinical Specimens Regulatory Class: Class II Product Code: QYT Dated: Mav 9, 2024 Received: May 10, 2024 Dear Xiao Kaiyu: We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading. If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register. Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" {1}------------------------------------------------ (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download). Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30. Design controls; 21 CFR 820.90. Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review. the OS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181). Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801 and Part 809); medical device reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safetyreporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050. All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rue"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advicecomprehensive-regulatory-assistance/unique-device-identification-system-udi-system. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-device-safety/medical-device-reportingmdr-how-report-medical-device-problems. For comprehensive regulatory information about mediation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medicaldevices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific regulatory topic. See the DICE website (https://www.fda.gov/medical-device-advice-comprehensive-regulatoryassistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email (DICE@fda.hhs.gov) or phone (1-800-638-2041 or 301-796-7100). {2}------------------------------------------------ Sincerely, Silke Schlottmann Digitally signed by Silke Schlottmann Digitally Schlottmann -S -ટ Date: 2024.09.30 13:17:20 -04'00' Silke Schlottmann, Ph.D. Deputy Assistant Director Bacteriology Respiratory and Medical Countermeasures Branch Division of Microbiology Devices OHT7: Office of In Vitro Diagnostics Office of Product Evaluation and Quality Center for Devices and Radiological Health Enclosure {3}------------------------------------------------ #### DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration # Indications for Use Form Approved: OMB No. 0910-0120 Expiration Date: 07/31/2026 See PRA Statement below. Submission Number (if known) K241317 Device Name Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) Indications for Use (Describe) The Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) is a visually read lateral flow immunoassay test intended for the qualitative detection of SARS-CoV-2 virus nucleocapsid protein antigen directly in anterior nasal swab specimens from individuals with signs and symptoms of COVID-19. This test is for non-prescription home use by individuals aged 14 years or older testing themselves, or adults testing individuals aged 2 years or older. All negative results are presumptive. Symptomatic individuals with an initial negative test result must be re-tested once between 48 and 72 hours after the first test using either an antigen test or a molecular test for SARS-CoV-2. Negative results do not rule out SARS-CoV-2 infections or other pathogens and should not be used as the sole basis for treatment. Positive results do not rule out co-infection with other respiratory pathogens. This test is not a substitute for visits to a healthcare provider or appropriate follow-up and should not be used to determine any treatments without provider supervision. Individuals who test negative and experience continued or worsening COVID-19 like symptoms, such as fever, cough and/or shortness of breath, should seek follow up care from their healthcare provider. The performance characteristics for SARS-CoV-2 were established from April, 2023 to February, 2024 when SARS-CoV-2 Omicron was dominant. Test accuracy may change as new SARS-CoV-2 viruses emerge. Additional testing with a lab-based molecular test (e.g., PCR) should be considered in situations where a new virus or variant is suspected. Type of Use (Select one or both, as applicable) Prescription Use (Part 21 CFR 801 Subpart D) |X | Over-The-Counter Use (21 CFR 801 Subpart C) ### CONTINUE ON A SEPARATE PAGE IF NEEDED. This section applies only to requirements of the Paperwork Reduction Act of 1995. #### *DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.* The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to: > Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff PRAStaff(@fda.hhs.gov "An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number." {4}------------------------------------------------ Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) # 510(k) Summary # Applicant Information | Submitter Name | Guangzhou Wondfo Biotech Co., Ltd. | |----------------|-------------------------------------------------------------------------------------------------------------| | Address | No.8 Lizhishan Road, Science City, Huangpu District, 510663 Guangzhou, Guangdong, China | | Contact Person | Kaiyu Xiao Senior Regulatory Affairs Manager Tel: +86-15005196892 E-mail: kaiyu.xiao@wondfo.com.cn | | Date Prepared | September 28, 2024 | # Device Information | Trade Name | Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) | |------------------------|-----------------------------------------------------| | Common Name | 2019-nCoV Antigen Test | | Classification | Class II | | Classification Name | Over-the-counter covid-19 antigen test | | Product Code | QYT | | Regulation Number | 21 CFR 866.3984 | | Review Panel | Microbiology | # Legally Marketed Predicate Device | Trade Name | Flowflex COVID-19 Antigen Home Test | |---------------|-------------------------------------| | 510(k) Number | K230828 | | Product Code | QYT | | Review Panel | Microbiology | {5}------------------------------------------------ Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) #### 1 Device Description The Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) is a lateral flow immunoassay intended for non-prescription home use qualitative detection of nucleocapsid protein antigen directly in anterior nasal swab specimens from individuals with signs and symptoms of COVID-19 within the first five (5) days of symptom onset. Results are for the identification of SARS-CoV-2 nucleocapsid protein antigen. The test cassette in the test kit is assembled with a test strip in a plastic housing that contains a nitrocellulose membrane with two lines: a test line (T line) and a control line (C line). The device is for in vitro diagnostic use only. The Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) consists of the following components: - . Tube Holder (located in kit box) - Test Cassette ● - Tube (pre-filled extraction buffer) ● - Swab ● - Quick Reference Instructions ● #### Indications for Use 2 The Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) is a visually read lateral flow immunoassay test intended for the qualitative detection of SARS-CoV-2 virus nucleocapsid protein antigen directly in anterior nasal swab specimens from individuals with signs and symptoms of COVID-19. This test is for non-prescription home use by individuals aged 14 years or older testing themselves, or adults testing individuals aged 2 years or older. All negative results are presumptive. Symptomatic individuals with an initial negative test result must be re-tested once between 48 and 72 hours after the first test using either an antigen test or a molecular test for SARS-CoV-2. Negative results do not rule out SARS-CoV-2 infections or other pathogens and should not be used as the sole basis for treatment. Positive results do not rule out co-infection with other respiratory pathogens. This test is not a substitute for visits to a healthcare provider or appropriate follow-up and should not be used to determine any treatments without provider supervision. Individuals who test negative and experience continued or worsening COVID-19 like symptoms, such as fever, cough and/or shortness of breath, should seek follow up care from their healthcare provider. {6}------------------------------------------------ Guangzhou Wondfo Biotech Co., Ltd. 510(k) Summary Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) The performance characteristics for SARS-CoV-2 were established from April 2023 to February 2024 when SARS-CoV-2 Omicron was dominant. Test accuracy may change as new SARS-CoV-2 viruses emerge. Additional testing with a lab-based molecular test (e.g., PCR) should be considered in situations where a new virus or variant is suspected. #### 3 Comparison to Predicate Device The Wondfo 2019-nCoV Antigen Test is substantially equivalent in principle and performance to Flowflex COVID-19 Antigen Home Test (K230828) which had been cleared by FDA. The comparison to predicate device is as follows the table below: | Item | Predicate Device Flowflex COVID-19 Antigen Home Test (K230828) | Candidate Device Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) | |--------------------------------------------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------| | Similarities | | | | Intended Use/ Indications for Use | The Flowflex COVID-19 Antigen Home Test is a visually read lateral flow immunoassay device intended for the rapid, qualitative detection of SARS- CoV-2 virus nucleocapsid protein antigen directly in anterior nasal swab specimens from individuals with signs and symptoms of COVID-19 within the first 6 days of symptom onset. | The Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) is a visually read lateral flow immunoassay test intended for the qualitative detection of SARS-CoV-2 virus nucleocapsid protein antigen directly in anterior nasal swab specimens from individuals with signs and symptoms of COVID-19. | | | This test is for non-prescription home use by individuals aged 14 years or older testing themselves, or adults testing individuals aged 2 years or older. | This test is for non-prescription home use by individuals aged 14 years or older testing themselves, or adults testing individuals aged 2 years or older. | | | The Flowflex COVID-19 Antigen Home Test does not differentiate between SARS- CoV and SARS-CoV-2. | All negative results are presumptive. Symptomatic individuals with an initial negative test result must be re- tested once between 48 and 72 hours after the first test using either an antigen test or a molecular test for SARS-CoV-2. Negative results do not rule out SARS-CoV-2 infections or other pathogens and should not be used as the sole basis for treatment. Positive results do not rule out co- infection with other respiratory pathogens. | | | All negative results are presumptive. Symptomatic individuals with an initial negative test result must be re- tested once between 48 and 72 | | | | hours after the first test using either an antigen test or a molecular test for SARS-CoV-2. Negative results do not preclude SARS-CoV-2 infections or other pathogens and should not be used as the sole basis for treatment. Positive results do not rule out co-infection with other respiratory pathogens. This test is not a substitute for visits to a healthcare provider or appropriate follow-up and should not be used to determine any treatments without provider supervision. Individuals who test negative and experience continued or worsening COVID-19 like symptoms, such as fever, cough and/or shortness of breath, should seek follow up care from their healthcare provider. The performance characteristics for SARS-CoV-2 were established from December 2022 to March 2023 when SARS-CoV-2 Omicron was dominant. Test accuracy may change as new SARS- CoV-2 viruses emerge. Additional testing with a lab- based molecular test (e.g., PCR) should be considered in situations where a new virus or variant is suspected. | This test is not a substitute for visits to a healthcare provider or appropriate follow-up and should not be used to determine any treatments without provider supervision. Individuals who test negative and experience continued or worsening COVID-19 like symptoms, such as fever, cough and/or shortness of breath, should seek follow up care from their healthcare provider. The performance characteristics for SARS-CoV-2 were established from April 2023 to February 2024 when SARS-CoV-2 Omicron was dominant. Test accuracy may change as new SARS-CoV-2 viruses emerge. Additional testing with a lab- based molecular test (e.g., PCR) should be considered in situations where a new virus or variant is suspected. | | Test Principle | Lateral flow immunoassay | Lateral flow immunoassay | | Sample type | Anterior nasal swab specimens | Anterior nasal swab specimens | | Assay targets | SARS-CoV-2 nucleocapsid protein antigens | SARS-CoV-2 nucleocapsid protein antigens | | Assay Type | Qualitative | Qualitative | | Read Results | Visual | Visual | | Intended users and use location | OTC, Patients or its guardians, At home or similar place | OTC, Patients or its guardians, At home or similar place | | Storage Temperature | 2°C to 30°C | 2°C to 30°C | | Assay Control | Internal procedural control | Internal procedural control | | Differences | | | | Time to Result | 15 minutes to 30 minutes | 10 minutes to 20 minutes | ### Table 1: Comparison to Predicate Device {7}------------------------------------------------ # Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) {8}------------------------------------------------ 510(k) Summary Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) #### Operation Principle ব The Wondfo 2019-nCoV Antigen Test is a sandwich immunochromatographic assay that uses antibodies to detect SARS-CoV-2 nucleocapsid antigen extracted from nasal swab specimen. A nasal swab sample is collected by the lay user and then inserted into the extraction buffer during which the extraction buffer disrupts the virus particles in the specimen to expose internal viral nucleocapsid antigens. The extracted specimen is added into the sample well of the test cassette. When an adequate volume of the specimen is added the sample well (S) of the test cassette, the specimen migrated by capillary action from the sample well over the conjugated pad and across the nitrocellulose membrane test strip. During the migration the reagents in the conjugated pad are solubilized. If SARS-CoV-2 nucleocapsid antigens are present in the sample, the antigens bind to the specific annti-SARS-CoV-2 antibody conjugated with dye particles on the conjugated pad and the antigen-antibody complexes captured by the anti-SARS-CoV-2 antibody immobilized at the test line region (T) to form sandwich complexes to generate a visible colored test line. Unbound conjugates continue to migrate across the nitrocellulose membrane and are captured at the control line region (C) to result in a visible colored control line that indicates adequate operations and sample flow during the test. If no SARS-CoV-2 nucleocapsid antigens are present in the sample, the conjugate will only be captured at the control line of the test. Results are interpreted between 10 and 20 minutes after adding the extracted sample into the sample well. A false negative or false positive result may occur if the test result before 10 minutes or after 20 minutes. {9}------------------------------------------------ Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) #### Non-clinical Performance 5 # 5.1 Lot-to-Lot Precision Precision was assessed by measuring repeatability using three levels of samples including negative samples, weak positive sample and a positive samples were prepared in negative clinical nasal swab matrix (NCM), blinded and randomized. 50uL were pipetted onto each swab and swabs were processed per the IFU. The following results were obtained from three kit lots testing each sample in duplicate per run by three operators and two runs per day over 20 days (3 lots × 3 operators × 2 replicates/sample × 2 runs/day/operator × 20 days). A total of 720 tests were run per panel member. In addition, a supplemental precision study was conducted testing negative samples and a sample below the LoD (0.9 x LoD) to demonstrate potential lot variability. These samples were tested with three lots by two operators for two replicates per run and two run per day over three days (3 lots × 2 operators × 2 replicates/sample × 2 runs/day/operator × 3 days). | Sample Level | % Agreement with Expected Result | | | | |------------------------------|----------------------------------|----------|---------|----------| | | Lot 1 | Lot2 | Lot 3 | Total | | Negative | 240/240 | 240/240 | 240/240 | 720/720 | | | (100%) | (100%) | (100%) | (100%) | | Weak positive (1.5 x LoD) | 240/240 | 240/240 | 240/240 | 720/720 | | | (100%) | (100%) | (100%) | (100%) | | Positive (3 x LoD) | 240/240 | 240/240 | 240/240 | 720/720 | | | (100%) | (100%) | (100%) | (100%) | | Negative | 24/24 | 24/24 | 24/24 | 72/72 | | | (100%) | (100%) | (100%) | (100%) | | 0.9x LoD SARS- CoV-2 | 20/24 | 20/24 | 24/24 | 64/72 | | | (83.33%) | (83.33%) | (100%) | (88.89%) | # 5.2 Analytical Sensitivity: Limit of Detection The Limit of Detection (LoD) of the Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) was determined by evaluating different dilutions of two (2) variants of inactivated SARS-CoV-2 in pooled negative nasal swab matrix. A 10-fold dilution series was made to determine the preliminary LoD, which was measured using three (3) device lots in triplicate measurements (n=3/lot). 50uL were pipetted onto each swab and swabs were processed per the IFU. The LoD was confirmed using 20 replicates for each of the same three (3) lots. The lowest viral concentration that was detected greater than or equal to 95% of the time (i.e., concentration at which at least 19 out of 20 replicates tested positive) was determined to be the LoD for that strain. The LoD was the same for all three lots tested. | Variant | Virus Strain | LoD | | |----------|--------------|-----------------|-----| | | | | | | Original | USA-WA1/2020 | $1.0\times10^4$ | 500 | {10}------------------------------------------------ | Guangzhou Wondfo Biotech Co., Ltd. | | | 510(k) Summary | |-----------------------------------------------------|------------------------|------------------|----------------| | Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) | | | | | Omicron BA.5 | USA/COR-22-063113/2022 | $3.33\times10^3$ | 166.7 | ### WHO Standard Testing The Limit of Detection (LoD) of the Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) was determined by using different dilutions of 1st WHO International Standard for SARS-CoV-2 antigen (NIBS code: 21/368) in pooled negative nasal swab matrix. 50uL were pipetted onto each swab and swabs were processed per the IFU. The LoD was determined for three different reagent lots as the lowest virus concentration that was detected ≥ 95% of the time (i.e., concentration at which at least 19 out of 20 replicates tested positive). The LoD was the same for all three lots tested. | WHO Standard | | LoD | | |--------------------|--------------------|-------------|---------| | | | IU/mL | IU/swab | | SARS-CoV-2 antigen | NIBSC code: 21/368 | $2.00x10^2$ | 10 | # 5.3 Inclusivity (Analytical Reactivity) Analytical reactivity for Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) was demonstrated using six (6) additional strains of SARS CoV-2 virus and one (1) SARS-CoV-2 JN.1 clinical specimen, in an LoD-like study. For six (6) additional strains of SARS CoV-2 virus, a 10-fold dilution series was made to determine the preliminary analytical reactivity concentration, which was measured using three (3) device lots and in triplicate measurements (n=3). The preliminary analytical reactivity concentration was confirmed using 20 replicates in triplicate using the same three (3) lots. 50uL were pipetted onto each swab and swabs were processed per the IFU. The lowest viral concentration that was detected greater than or equal to 95% of the time (i.e., concentration at which at least 19 out of 20 replicates tested positive) was determined to be the analytical reactivity concentration for that strain. For JN.1 variant testing, one (1) clinical specimen was serially diluted and tested with 5 replicates per dilution/concentration. The lowest concentration that detected 5 positive out of 5 samples represents analytical reactivity concentration for JN.1. The analytical reactivity of the Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) with the variants is shown in table below: | Variant | Virus Strain | Lowest Reactivity Concentration | |-------------------|-------------------------------------|------------------------------------| | Alpha | England/204820464/2020 | $1.0×10^3$ TCID50/mL | | Beta | South_Africa/KRISP- K005325/2020 | $1.0×10^3$ TCID50/mL | | Gamma | Japan/TY7-503/2021 | $1.0×10^3$ TCID50/mL | | Delta | USA/PHC658/2021 | $1.0×10^2$ TCID50/mL | | Omicron B.1.1.529 | USA/MD-HP20874/2021 | $1.0×10^2$ TCID50/mL | | Omicron BA.2.3 | USA/MD-HP24556/2022 | $3.33×10^2$ TCID50/mL | | JN.1 | Clinical specimen | Ct=27.9 ( $2.28×10^4$ GE/mL) | {11}------------------------------------------------ Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) # 5.4 Analytical Specificity #### Microorqanism Cross-Reactivity and Microbial Interferences To demonstrate that the device does not react with related viruses, other infectious pathogens, and normal flora that are reasonably likely to be encountered in nasal swab specimens cross-Reactivity and Microbial Interference of the Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) was evaluated by testing 30 microorganisms diluted into negative clinical nasal swab matrix and a sample of pooled nasal wash. Each microorganism was tested in three (3) replicates in the absence and presence of SARS-CoV-2 (USA/COR-22-063113/2022) at 2xLoD. None of the organisms and viruses evaluated demonstrated cross-reactivity or microbial interference in this assay at the concentrations tested. | Microorganism | Final Concentration | Cross-Reactivity (no analyte) (# pos reps/total reps) | Interference (2xLoD SARS-CoV-2) (# pos reps/total reps) | |---------------------------------------------|---------------------|----------------------------------------------------------------|---------------------------------------------------------------| | Human coronavirus 229E | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Human coronavirus OC43 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Human coronavirus NL63 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | MERS-coronavirus | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Coronavirus HKU 1 (n=2)* | Ct = 20.5 - 22 | 0/6 | 6/6 | | SARS-CoV Nucleocapsid Protein (His Tag)# | 0.25 ng/mL | 0/3 | 3/3 | | Human Adenovirus 1 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Human Metapneumovirus (hMPV- 5) Type B1 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Parainfluenza virus Type 1 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Parainfluenza virus Type 2 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Parainfluenza virus Type 3 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Parainfluenza virus Type 4A | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Enterovirus | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Respiratory syncytial virus | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Rhinovirus | 5.62 x 104TCID50/mL | 0/3 | 3/3 | | Influenza A/Victoria/4897/22 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Influenza A/Darwin/6/21 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Influenza B/Washington/02/19 | 2 x 105 TCID50/mL | 0/3 | 3/3 | | Influenza B/Florida/04/06 | 1.17 x 105TCID50/mL | 0/3 | 3/3 | | Haemophilus influenzae type b | 2 x 106 CFU/mL | 0/3 | 3/3 | | Bordetella pertussis | 2 x 106 CFU/mL | 0/3 | 3/3 | | Candida albicans | 2 x 106 CFU/mL | 0/3 | 3/3 | | Chlamydia pneumoniae | 2 x 106 IFU/mL | 0/3 | 3/3 | | Legionella pneumophila | 2 x 106 CFU/mL | 0/3 | 3/3 | | Mycoplasma tuberculosis | 2 x 106 CFU/mL | 0/3 | 3/3 | | Mycoplasma pneumoniae | 2 x 106 CCU/mL | 0/3 | 3/3 | | Staphylococcus aureus MRSA | 2 x 106 CCU/mL | 0/3 | 3/3 | | Staphylococcus epidermidis | 2 x 106 CFU/mL | 0/3 | 3/3 | {12}------------------------------------------------ 510(k) Summary Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) | Streptococcus pneumoniae | 2 x 106 CFU/mL | 0/3 | 3/3 | |--------------------------------------------------|----------------|-----|-----| | Streptococcus pyogenes | 2 x 106 CFU/mL | 0/3 | 3/3 | | Pneumocystis jirovecii (PJP) - S. cerevisiae# | 2x106 CFU/mL | 0/3 | 3/3 | | Pooled human nasal wash | NA | 0/3 | 3/3 | | #Recombinant protein/strains were tested as the live or inactivated strains were hard to obtain #### Interfering Substances Forty-two (42) potentially interfering substances, diluted in negative nasal swab matrix, were tested with the Wondfo 2019-nCoV Antigen Test (Lateral Flow Method). Each substance was tested in three (3) replicates in the absence and presence of heatinactivated SARS-CoV-2 (isolate USA/COR-22-063113/2022) at 2xLoD. The endogenous and exogenous interfering substances do not cross-react or interfere with the performance of the device at the concentrations tested. | Interfering Substances | Concentration | Cross-Reactivity (no analyte) (# pos reps/total reps) | Interference (2xLoD SARS-CoV-2) (# pos reps/total reps) | |---------------------------------------------------|---------------|-------------------------------------------------------------|---------------------------------------------------------------| | Whole Blood | 2.5% | 0/3 | 3/3 | | Mucin | 2.5mg/mL | 0/3 | 3/3 | | Chloraseptic sore throat lozenges (Benzocaine) | 3mg/mL | 0/3 | 3/3 | | Chloraseptic sore throat lozenges (Menthol) | 3mg/mL | 0/3 | 3/3 | | NeilMed (Sodium chloride with preservatives) | 15% v/v | 0/3 | 3/3 | | CVS Nasal Drops (Phenylephrine) | 15% v/v | 0/3 | 3/3 | | Afrin (Oxymetazoline) | 15% v/v | 0/3 | 3/3 | | CVS Nasal Spray (Cromolyn) | 15% v/v | 0/3 | 3/3 | | Zicam | 15% v/v | 0/3 | 3/3 | | Homeopathic (Alkalol) | 15% v/v | 0/3 | 3/3 | | Sore Throat Phenol Spray | 5% w/v | 0/3 | 3/3 | | Tobramycin | 4 µg/mL | 0/3 | 3/3 | | Mupirocin | 10 mg/mL | 0/3 | 3/3 | | Fluticasone Propionate | 15% v/v | 0/3 | 3/3 | | Tamiflu (Oseltamivir Phosphate) | 5mg/mL | 0/3 | 3/3 | | Biotin | 3.5 µg/mL | 0/3 | 3/3 | | Menthol | 0.015% w/v | 0/3 | 3/3 | | Bleach | 0.01% v/v | 0/3 | 3/3 | | Dish Soap | 1% v/v | 0/3 | 3/3 | | Laundry Detergent | 1% v/v | 0/3 | 3/3 | | Multisurface Cleaner | 1% v/v | 0/3 | 3/3 | | Hand Soap | 1% v/v | 0/3 | 3/3 | {13}------------------------------------------------ 510(k) Summary Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) | Interfering Substances | Concentration | Cross-Reactivity (no analyte) (# pos reps/total reps) | Interference (2xLoD SARS-CoV-2) (# pos reps/total reps) | |---------------------------|----------------------|-------------------------------------------------------------|---------------------------------------------------------------| | Laundry Detergent | 1% w/v | 0/3 | 3/3 | | Bar Soap | 1% w/v | 0/3 | 3/3 | | Multipurpose Cleaner | 1% v/v | 0/3 | 3/3 | | Hand Sanitizer | 1% v/v | 0/3 | 3/3 | | Aspirin | 15 mg/mL | 0/3 | 3/3 | | Motrin (Ibuprofen) | 50 mg/mL | 0/3 | 3/3 | | Naproxen | 20 mg/mL | 0/3 | 3/3 | | Budesonide | 15% v/v | 0/3 | 3/3 | | Flunisolide | 15% v/v | 0/3 | 3/3 | | Triamcinolone | 15% v/v | 0/3 | 3/3 | | Dexamethasone | 5 mg/mL | 0/3 | 3/3 | | Beclomethasone | 15% v/v | 0/3 | 3/3 | | Remdesivir | 5 mg/mL | 0/3 | 3/3 | | Molnupiravir | 5 mg/mL | 0/3 | 3/3 | | Leukocytes | ≥1 x10^6 cells/mL | 0/3 | 3/3 | | Zinc | 15% v/v | 0/3 | 3/3 | | Luffa opperculata | 1.25% | 0/3 | 3/3 | | Galphimia glauca | 15% v/v | 0/3 | 3/3 | | Histaminum hydrochloricum | 15% v/v | 0/3 | 3/3 | | Zanamivir | 10mg/mL | 0/3 | 3/3 | # 5.5 High Dose Hook Effect No high-dose hook effect was observed when Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) was used to test specimens containing SARS-CoV-2 Omicron Lineage BA.5 (hCoV19/USA/COR-22-063113/2022) viral concentration as high as 1.98 x 10º TCID50/mL. ### 5.6 Usability and User Comprehension Studies ### Usability Study A usability study was conducted to assess the lay user's ability to understand the instructions for use and to adequately execute the device accordingly. A total of 30 participants, aged 14 years and older and caregiver-child (ages 2-13 years) pairs and caregiver-adult pairs, were enrolled in the study and were observed during testing. A total of 30 participants completed testing monitored by investigators. Following the usability study, all subjects were assessed for their understanding and were issued a questionnaire to assess users' comprehension of the test. The questionnaire was completed by 30 subjects. The questionnaire assessed users' understanding of concepts such as the test {14}------------------------------------------------ Wondfo 2019-nCoV Antigen Test (Lateral Flow Method) purpose and interpretation of results. The results of each study were deemed acceptable and demonstrated that the instructions for use were easy to follow. ### Readability Study The purpose of this study was to evaluate whether lay users (patients or their caregivers) can interpret test results correctly with low positive samples from the Wondfo 2019-nCoV Antigen Test (Lateral Flow Method). The Readability Study was conducted in a simulated home environment. A total of 50 lay users with diverse gender, ages and educational background who met the study inclusion criteria, were enrolled for the Readability Study. Each lay user was asked to interpret two panels of 5 test devices with three different concentrations that were arranged in blinded test panels with the following sample results; the order of the results within the panel was randomized: - Panel 1: Negative, 1.5xLoD, 1.5xLoD, 5xLoD, Invalid - Panel 2: Negative, Negative, 1.5xLoD, 5xLoD, Invalid 42% (21/50) of the study participants were male and 58% (29/50) of the study participants were female. 64% (32/50) of individuals were vision impaired, and 18% (9/50) of individuals were either still at high school or had a high school degree as their highest level of education. Readability outcomes are shown in the table below. | Sample Level | Number of Test Results Across all Participants | Number of Correct Interpretation | Observed Performance (%) | |--------------|------------------------------------------------------|-------------------------------------|-----------------------------| | Negative | 150 | 146 | 97.33% | | 1.5xLoD | 150 | 140 | 93.33% | | 5xLoD | 100 | 100 | 100% | | Invalid | 100 | 100 | 100% | #### Clinical studies 6 A prospective study was performed in which one thousand and fifty-three (1053) direct anterior nasal swab specimens were sequentially enrolled (between April 2023 and February 2024) and tested fresh with the Wondfo 2019-nCoV Antigen Test (Lateral Flow Method). The samples were collected from symptomatic patients suspected of infection with respiratory symptoms, at nine (9) clinical sites. Subjects performed testing on selfcollected swab samples in age groups 14 and older, and adult collected samples for age groups 2-13, in a simulated at-home environment. To be enrolled in the study, patients had to present at the participating study site with signs and symptoms of respiratory infection generally observed from SARS-CoV-2 during the study period. Two anterior na…