iHealth COVID-19 Antigen Rapid Test

{0} FDA U.S. FOOD & DRUG ADMINISTRATION # 510(k) SUBSTANTIAL EQUIVALENCE DETERMINATION DECISION SUMMARY ASSAY ONLY ## I. Background Information: A. 510(k) Number: K233842 B. Applicant: iHealth Labs, Inc C. Proprietary and Established Names: iHealth COVID-19 Antigen Rapid Test D. Regulatory Information: | Product Code(s) | Classification | Regulation Section | Panel | | --- | --- | --- | --- | | QYT | Class II | 21 CFR 866.3984 - Over-The-Counter Test To Detect Sars-Cov-2 From Clinical Specimens | MI - Microbiology | ## II. Submission/Device Overview: A. Purpose for Submission: To obtain 510(k) clearance for the iHealth COVID-19 Antigen Rapid Test. B. Measurand: Nucleocapsid protein antigen from SARS-Coronavirus 2 (SARS-CoV-2) C. Type of Test: Qualitative lateral flow immunoassay Food and Drug Administration 10903 New Hampshire Avenue Silver Spring, MD 20993-0002 www.fda.gov {1} III. Intended Use/Indications for Use: A. Intended Use(s): See Indications for Use below. B. Indication(s) for Use: The iHealth COVID-19 Antigen Rapid 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. This test is for non-prescription home use by individuals aged 15 years or older testing themselves, or adults testing individuals aged 2 years or older. The iHealth COVID-19 Antigen Rapid 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 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 October 2022 to June 2023 when the COVID-19 variant 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. C. Special Conditions for Use Statement(s): OTC - Over The Counter D. Special Instrument Requirements: Not applicable IV. Device/System Characteristics: A. Device Description: The iHealth COVID-19 Antigen Rapid Test employs lateral flow immunoassay technology to allow for the rapid detection of nucleocapsid protein from the SARS-CoV-2 virus. This test does not differentiate between SARS-CoV and SARS-CoV-2. K233842 - Page 2 of 19 {2} The test package is composed of the following components: - Test Cassette (test card, individually packaged) - Extraction Buffer Tube - Disposable Sterile Nasal Swab - Package Insert containing Quick Reference Instructions The test cassette is assembled with a test strip in a plastic housing, that contains a nitrocellulose membrane coated with two test lines: a test line (T line) and a control line (C line). ## B. Principle of Operation: To begin the test, a self-collected anterior nares swab sample (ANS) in individuals aged 15 and older or an ANS swab collected by a parent or guardian in individuals between the age of 2 to 14 is inserted into the sample tube. The sample tube contains sample extraction buffer. This buffer lyses any virions contained in the specimen and facilitates exposure of the appropriate viral antigens to the antibodies used in the test. The lysed sample liquid in the sample tube is then added to the Sample Port of the test cassette. If the extracted specimen contains SARS-CoV-2 antigens, a pink-to-purple T Line from the formation of SARS CoV-2 antigen immune complexes, along with a pink-to-purple C Line will appear on the cassette indicating a positive result. If SARS-CoV-2 antigens are not present, or present at levels below the limit of detection, only a pink-to-purple C Line will appear. The C Line must appear for a sample result to be valid and interpretable. iHealth Application: The iHealth mobile application constitutes electronic labeling that allows for digitally guided testing of anterior nasal swab samples self-collected from lay users and reporting of results. The software application is intended for use with the iHealth COVID-19 Antigen Rapid Test over the counter (OTC) device as an alternative to the paper copy of the Instructions for Use (IFU) provided in the test kit. The iHealth application is intended only to guide the user in the preparation and execution of the iHealth COVID-19 Antigen Rapid Test, it does not interpret the test result. ## V. Substantial Equivalence Information: ### A. Predicate Device Name(s): Flowflex COVID-19 Antigen Home Test ### B. Predicate 510(k) Number(s): K230828 ### C. Comparison with Predicate(s): | Device & Predicate Device(s): | K233842 (Candidate Device) | K230828 (Predicate) | | --- | --- | --- | | Device Trade Name | iHealth COVID-19 Antigen Rapid Test | ACON Flowflex COVID-19 Antigen Home Test | | General Device Characteristic Similarities | | | K233842 - Page 3 of 19 {3} | Device & Predicate Device(s): | K233842 (Candidate Device) | K230828 (Predicate) | | --- | --- | --- | | Intended Use/Indications For Use | The iHealth COVID-19 Antigen Rapid Test is a visually read lateral flow immunoassay device intended for the rapid, qualitative detection of SARS-CoV-2 nucleocapsid protein antigens directly in anterior nasal (nares) swab specimens from individuals with signs and symptoms of COVID-19 within the first 6 days from symptom onset. This test is for non-prescription home use by individuals aged 15 years or older testing themselves, or adults testing individuals aged 2 years or older. The iHealth COVID-19 Antigen Rapid 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 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, | 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. 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-CoV2. 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 coinfection 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, | K233842 - Page 4 of 19 {4} | Device & Predicate Device(s): | K233842 (Candidate Device) | K230828 (Predicate) | | --- | --- | --- | | | 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 October 2022 to June 2023 when the COVID-19 variant 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. | 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 SARSCoV-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. | | Regulation Number | 21 CFR 866.3984 | Same | | Product Code | QYT | Same | | Analyte | SARS CoV-2 nucleocapsid | Same | | Intended Use Setting | OTC | Same | | Intended Use Population | Symptomatic | Same | | Usage Type | Single use | Same | | Specimen Type | Direct Anterior Nasal Swab | Same | | Test Result Type | Qualitative | Same | | Technology | Lateral flow immunoassay | Same | | Detection Format | Visually read | Same | | Time to Result | 15-30 minutes | Same | | Storage Condition | 2-30°C | Same | The differences in the iHealth COVID-19 Antigen Rapid Test (proposed device) and the ACON Flowflex COVID-19 Antigen Home Test (predicate device, K230828) are limited to the minimum age for self-collection and self-testing. This difference does not affect the overall substantial equivalence of the proposed device to the predicate device in terms of the technological similarity, intended use, safety, and effectiveness. VI. Standards/Guidance Documents Referenced: | Document | Title | Publisher | Applicable Study | | --- | --- | --- | --- | | Special Controls under 21 CFR 866.3984 (Over-the-counter test to detect SARS-CoV-2) | Reclassification order for DEN220028 and special controls under 21 CFR 866.3984 | FDA/CDRH | All Studies | K233842 - Page 5 of 19 {5} | Document | Title | Publisher | Applicable Study | | --- | --- | --- | --- | | ISO11135:2014 | Sterilization of health care products - Ethylene oxide - Requirements for development, validation and routine control of a sterilization process for medical devices | ISO | Sterility | | ISO 10993-7 | Biological Evaluation of Medical Devices – Part 7: Ethylene Oxide Sterilization Residuals | ISO | Sterility | | FDA Guidance | Submission and Review of Sterility Information in Premarket Notification (510(k)) Submissions for Devices Labeled as Sterile | FDA. | FDA/CDRH | Sterility | | ISO 10993-5 | Biological evaluation of medical devices Part 5: Tests for in vitro cytotoxicity | ISO | Biocompatibility | | ISO 10993-10 | Biological evaluation of medical devices Part 10: Tests for irritation and skin sensitization | ISO | Biocompatibility | VII. Performance Characteristics A. Analytical Performance: 1. Multi-Site Reproducibility: The purpose of the study was to assess between-site and between-lot variability of three different lots of the iHealth COVID-19 Antigen Rapid Test. Three (3) levels of heat-inactivated SARS-CoV-2 were spiked in negative clinical matrix (NCM, Nasal fluid diluted in 1:3 Saline) as follows: A. Negative, NCM B. Low positive (1x LoD) C. Positive (3x LoD) Sample panels for use on each day of the study were prepared at a central site, randomized and frozen at -70 °C for transport to the lab sites where they were thawed at room temperature before testing. The fresh frozen stability of the sample panel was confirmed by an appropriately designed fresh frozen study. The sample panel was tested in a blinded manner by three operators at three CLIA waived sites for 5 non-consecutive days. Each operator applied 50 μL of each coded sample to each dry nasal swab. Then, the operator processed the sample per the IFU of the proposed device. All three lots were tested by each operator on each testing day. Each sample level was tested in triplicate in each run per operator K233842 - Page 6 of 19 {6} per day (i.e., 3 lots x 3 operators x 3 replicates/run x 5 days). A total of 405 tests were run for each concentration level in the panel. The agreement of obtained results with expected results was 100% for all samples across all lots, operators, and days. Variability in results was not observed between the three independently manufactured lots. The results are summarized in Table 1 below: Table 1: Reproducibility Study Results | Site | True Negative | Low Positive (1x LoD) | Positive (3x LoD) | | --- | --- | --- | --- | | Site 1 (External, 3 operators) | 135/135 | 135/135 | 135/135 | | Site 2 (External, 3 operators) | 135/135 | 135/135 | 135/135 | | Site 3 (External, 3 operators) | 135/135 | 135/135 | 135/135 | | Total | 405/405 | 405/405 | 405/405 | | % Agreement | 100% | 100% | 100% | | 95% CI | 99.1-100% | 99.1-100.% | 99.1-100% | 2. Linearity Not applicable, the device is a binary qualitative assay that is visually read. 3. Analytical Specificity/Interference: a. Cross Reactivity/Microbial Interference To demonstrate that the iHealth COVID-19 Antigen Rapid Test does not react with related viruses, high prevalence disease agents, and normal or pathogenic flora that are reasonably likely to be encountered in nasal swab specimens, the analytical specificity of the iHealth COVID-19 Antigen Rapid Test was evaluated by testing various microorganisms (22), viruses (31), and negative clinical matrix (1) in the absence (cross-reactivity) and presence (microbial interference) of SARS-CoV-2 at 2x LoD (2.66x10⁴ TCID₅₀/mL). Each organism and each virus was tested in five (5) replicates using heat-inactivated SARS-CoV-2 (hCoV-19/South Africa/CERI-KRISP-K040013/2022). The microbial interference and the cross-reactivity study were conducted simultaneously with samples tested in a randomized and blinded manner. None of the organisms and viruses above showed cross-reactivity and interference in the assay at the concentrations listed in summary Table 2 below. Table 2: Cross Reactivity and Microbial Interference Results | Microorganism | Concentration Tested | Cross-Reactivity Negative Agreement | Interference Positive Agreement | | --- | --- | --- | --- | | Adenovirus Type 1 | 2.82 x 10⁶ TCID₅₀/mL | 5/5 | 5/5 | | Adenovirus Type 4 | 2.84 x 10⁵ TCID₅₀/mL | 5/5 | 5/5 | K233842 - Page 7 of 19 {7} K233842 - Page 8 of 19 | Microorganism | Concentration Tested | Cross-Reactivity Negative Agreement | Interference Positive Agreement | | --- | --- | --- | --- | | Adenovirus Type 7A | 3.16 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Adenovirus Type 8 | 1.13 x 10^{5} U/mL | 5/5 | 5/5 | | Adenovirus Type 31 | 1.13 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Adenovirus Type 41 | 3.80 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Bordetella pertussis | 1.16 x 10^{9} CFU/mL | 5/5 | 5/5 | | Candida albicans | 1.31 x 10^{7} CFU/mL | 5/5 | 5/5 | | Chlamydia pneumonia | 1.33 x 10^{8} IFU/mL | 5/5 | 5/5 | | Enterovirus, Type 68 | 2.84 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Enterovirus, Type 71 | 1.13 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Haemophilus influenzae | 1.42 x 10^{8} CFU/mL | 5/5 | 5/5 | | Human coronavirus 229E | 4.50 x 10^{4} TCID_{50}/mL | 5/5 | 5/5 | | Human coronavirus HKU1 (Np swab) | Ct 33.8 | 5/5 | 5/5 | | Human coronavirus NL63 | 2.84 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Human coronavirus OC43 | 1.36 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Human Metapneumovirus 3, type B1 | 9.4 x 10^{4} TCID_{50}/mL | 5/5 | 5/5 | | Human Metapneumovirus 4, type B2 | 3.33 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Human Metapneumovirus 9 Type A1 | 1.13 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Influenza A H3N2 (Wisconsin/67/05 | 1.13 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Influenza B (Victoria/504/00) | 1.26 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Legionella pneumophila | 1.42 x 10^{9} CFU/mL | 5/5 | 5/5 | | MERS-coronavirus (NATrol Stock) | Ct 27.1 | 5/5 | 5/5 | | SARS-coronavirus | 1.0 x 10^{5} CFU/mL | 5/5 | 5/5 | | Mycobacterium tuberculosis | 1.21 x 10^{7} CFU/mL | 5/5 | 5/5 | | Mycoplasma pneumoniae | 2.16 x 10^{8} CCU/mL | 5/5 | 5/5 | | Parainfluenza virus 1 | 3.80 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Parainfluenza virus 2 | 3.39 x 10^{6} TCID_{50}/mL | 5/5 | 5/5 | | Parainfluenza virus 3 | 1.15 x 10^{6} TCID_{50}/mL | 5/5 | 5/5 | | Parainfluenza virus 4A | 1.13 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Parainfluenza virus 4B | 9.55 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Pooled human nasal cavity wash | n/a | 5/5 | 5/5 | | Pseudomonas aeruginosa | 7.09 x 10^{8} CFU/mL | 5/5 | 5/5 | | Respiratory syncytial virus A | 1.05 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Respiratory syncytial virus B | 1.51 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Rhinovirus, Type 1A | 1.13 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Staphylococcus aureus | 1.42 x 10^{8} CFU/mL | 5/5 | 5/5 | | Staphylococcus epidermidis | 6.84 x 10^{8} CFU/mL | 5/5 | 5/5 | | Streptococcus salivarius | 1.35 x 10^{8} CFU/mL | 5/5 | 5/5 | | Streptococcus pneumoniae | 7.22 x 10^{7} CFU/mL | 5/5 | 5/5 | | Streptococcus pyogenes | 4.60 x 10^{8} CFU/mL | 5/5 | 5/5 | {8} K233842 - Page 9 of 19 | Microorganism | Concentration Tested | Cross-Reactivity Negative Agreement | Interference Positive Agreement | | --- | --- | --- | --- | | Corynebacterium diphtheriae | 3.43 x 10^{7} CFU/mL | 5/5 | 5/5 | | Escherichia coli | 8.16 x 10^{8} CFU/mL | 5/5 | 5/5 | | Lactobacillus acidophilus | 6.58 x 10^{7} CFU/mL | 5/5 | 5/5 | | Moraxella catarrhalis | 5.92 x 10^{7} CFU/mL | 5/5 | 5/5 | | Neisseria Elongata | 1.07 x 10^{9} CFU/mL | 5/5 | 5/5 | | Neisseria meningitidis serogroup A | 2.04 x 10^{7} CFU/mL | 5/5 | 5/5 | | Neisseria meningitidis serogroup B | 9.15 x 10^{7} CFU/mL | 5/5 | 5/5 | | Neisseria meningitidis serogroup C | 7.90 x 10^{7} CFU/mL | 5/5 | 5/5 | | Epstein-Barr virus | 9.70 x 10^{6} cp/mL | 5/5 | 5/5 | | Mumps virus | 9.55 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Cytomegalovirus (CMV) | 1.13 x 10^{5} TCID_{50}/mL | 5/5 | 5/5 | | Measles virus | 1.23 x 10^{7} TCID_{50}/mL | 5/5 | 5/5 | ## b. Interfering Substances: Thirty-one (31) potentially interfering substances were evaluated with the iHealth COVID-19 Antigen Rapid Test. Each substance was tested in three (5) replicates in the absence or presence of heat-inactivated SARS-CoV-2 (hCoV-19/South Africa/CERI-KRISP-K040013/2022) at 2x LoD. None of the endogenous and exogenous substances listed in table below interfered with the assay at the concentration listed in Table 3. Table 3: Interfering Substances Testing Results | Interfering Substances Tested | Without SARS-CoV-2 | | With 2x LoD SARS-CoV-2 | | | --- | --- | --- | --- | --- | | | Concentration Tested | Positive/Tested | Concentration Tested | Positive/Tested | | Sore Throat & Cough Lozenges (Benzocaine), | 3 mg/mL | 0/5 | 3 mg/mL | 5/5 | | Throat Lozenges (Menthol) | 3 mg/mL | 0/5 | 10 mg/mL | 5/5 | | Sore Throat Spray (Phenol) | 5% v/v | 0/5 | 5% v/v | 5/5 | | Mucin, bovine submaxillary type I-S | 2.5 mg/mL | 0/5 | 2.5 mg/mL | 5/5 | | Whole Blood | 2.5% v/v | 0/5 | 2.5% | 5/5 | | Leukocytes | 4.8 x 10^{6} cells/mL | 0/5 | 4.8 x 10^{6} cells/mL | 5/5 | | Zinc | 5% v/v | 0/5 | 5% v/v | 5/5 | | Nasal spray (Phenylephrine HCl) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal spray (Cromolyn sodium nasal solution) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal spray Afrin (Oxymetazoline HCl) | 15% v/v | 0/5 | 15% v/v | 5/5 | {9} | Interfering Substances Tested | Without SARS-CoV-2 | | With 2x LoD SARS-CoV-2 | | | --- | --- | --- | --- | --- | | | Concentration Tested | Positive/Tested | Concentration Tested | Positive/Tested | | Nasal spray (Sodium Chloride & Preservatives) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal corticosteroids (Beclomethasone dipropionate) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal corticosteroids (dexamethasone) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal corticosteroids (Flunisolide) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal corticosteroids Nasocort Allergy 24 hour (Triamcinolone Acetonide) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal corticosteroids Rhinocort (Budesonide /Glucocorticoid) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal corticosteroids (Mometasone furoate) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal corticosteroids (fluticasone propionate) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Nasal gel ((Homeopathic Luffa opperculata Galphimia glauca) | 1.25% | 0/5 | 1.25% | 5/5 | | Nasal gel ((Luffa opperculata sulfur) | 1.25% | 0/5 | 1.25% | 5/5 | | Homeopathic allergy relief (Galphimia glauca) | 15% w/v | 0/5 | 15% w/v | 5/5 | | Homeopathic allergy relief (histaminum hydrochloricum) | 15% w/v | 0/5 | 15% w/v | 5/5 | | Homeopathic nasal wash (Alkalol) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Homeopathic nasal wash (Zicam) | 15% v/v | 0/5 | 15% v/v | 5/5 | | Oseltamivir Phosphate (Tamiflu) | 5 mg/mL | 0/5 | 5 mg/mL | 5/5 | | Remdesivir | 5 mg/mL | 0/5 | 5 mg/mL | 5/5 | | Anti-viral drugs (Molnupiravir) | 5 mg/mL | 0/5 | 5 mg/mL | 5/5 | | Antibiotic, nasal ointment (Mupirocin) | 10 mg/mL | 0/5 | 10 mg/mL | 5/5 | | Hand sanitizer | 15% v/v | 0/5 | 15% v/v | 5/5 | | Hand Soap | 15% v/v | 0/5 | 15% v/v | 5/5 | ## c. Biotin Interference The iHealth COVID-19 Antigen Rapid Test uses streptavidin/biotin technology for antibody immobilization. Using the same protocol as for the Endogenous Interference Studies, the iHealth COVID-19 Antigen Rapid Test was tested for biotin interference up to 3500 ng/mL. As shown in Table 4, biotin interference was observed at concentrations at or above 350 ng/mL. K233842 - Page 10 of 19 {10} Table 4: Biotin Interference Study Results | Biotin Concentration (ng/mL) | No SARS CoV-2 (negative agreement) | SARS CoV-2 at 2x LoD (positive agreement) | | --- | --- | --- | | 200 | 0/5 | 5/5 | | 350 | 0/5 | 3/5 | | 700 | 0/5 | 0/5 | | 1750 | 0/5 | 0/5 | | 3500 | 0/5 | 0/5 | 4. Assay Reportable Range: Not applicable, the device is a binary qualitative assay that is visually read. 5. Traceability, Stability, Expected Values (Controls, Calibrators, or Methods): a. Internal Controls The iHealth COVID-19 Antigen Rapid Test contains the control line (C) of the device as an internal procedural control that indicates whether the applied specimen has migrated properly across the device. The sample pad of the device contains control IgG molecules that are captured at the control line by specific anti-IgG antibodies. As sample addition wicks into the membrane and resolves the reagents in the sample pad a red colored line indicating the formation of immune complexes should appear at the control line when sufficient sample is added. If the extracted specimen contains SARS-CoV-2 antigens, a pink-to-purple T Line, along with a pink-to-purple C Line will appear on the COVID-19 Test Card indicating a positive result. If SARS-CoV-2 antigens are not present, or present at very low levels, only the pink-to-purple C Line will appear. Test results without a visible control line cannot be interpreted (i.e., are invalid) and need to be retested with a new sample and a new device. b. Sample Stability Samples in the OTC environment will not undergo storage as the IFU instructs the user to immediately proceed from the sample collection to the testing steps. c. Real-Time Stability Shelf-life of the iHealth COVID-19 Antigen Rapid Test under the intended storage condition (2-30°C) was assessed in a real-time stability study using three (3) lots of test kit stored at 2-8°C with 41.3% - 45.6% RH, and 30°C with 91.4% - 95.4 RH. The test kits were assessed with negative samples and contrived positive samples prepared using heat inactivated SARS CoV-2 hCoV-19/South Africa/CERI-KRISP-K040013/2022 (Lineage BA.5) at 3x LoD. Five replicates per timepoint per storage condition were analyzed. The data collected in this study supports a shelf life of 13 months. d. Transportation Stability The stability of the iHealth COVID-19 Antigen Rapid Test kit under different shipping conditions was determined for three lots of test kits that were stored at two different temperature conditions: K233842 - Page 11 of 19 {11} 1. Winter Profile: Kits were stored at $20^{\circ}\mathrm{C}$ with 11.2 - 15.4% relative humidity for 7 days, followed by $18^{\circ}\mathrm{C}$ at the same RH conditions for 4 hours (winter profile) 2. Summer Profile: Kits were stored at $45^{\circ}\mathrm{C}$ at $90.2\% - 93.9\%$ RH for 7 days followed by $22^{\circ}\mathrm{C}$ at the same RH conditions for 4 hrs. (summer profile). All negative samples tested negative, all positive samples (3x LoD, 4.0 x104 TCID50/mL) tested positive in all storage conditions at the 7-day time point. # 6. Detection Limit: # a. LoD Testing The LoD of the was determined by evaluating different dilutions of heat-inactivated SARS-CoV-2 (hCoV-19/South Africa/CERI-KRISP-K040013/2022 (Lineage BA.5) in negative nasal matrix (NNM). The LoD was determined as the lowest virus concentration that was detected $\geq 95\%$ of the time (i.e., concentration at which at least 19 out of 20 replicates tested positive). The limit of detection was established in two (2) phases: a range finding and a confirmatory LoD study. # Range Finding LoD Study Five serial dilutions were made from heat inactivated SARS-CoV-2 virus into negative nasal matrix (NNM). Five (5) replicates were tested on one kit lot of the assay for each of five 1:10 dilutions to determine the preliminary LoD concentration of the device. The lowest concentration with 5/5 positive results from each lot was considered the preliminary LoD. For each replicate 50 $\mu$ L of virus dilution was applied to a swab and the swab was processed according to the IFU. The results are summarized below in Table 5: Table 5: Preliminary LoD Study Summary | Concentration of SARS CoV-2 applied to dry swab | Kit Lot 2023014 Positive/ Tested | | --- | --- | | 3.98 x 106TCID50/mL | 5/5 | | 3.98 x 105TCID50/mL | 5/5 | | 3.98 x 104TCID50/mL | 5/5 | | 3.98 x 103TCID50/mL | 3/5 | | 3.98 x 102TCID50/mL | 0/5 | # Confirmatory LoD Study The preliminary LoD test sample concentration and a 3-fold dilution series were tested on each of 3 lots on three consecutive days. The Sponsor tested a total of twenty $(n = 20)$ replicates for the confirmatory dilutions to confirm the LoD for each lot, at least 19 of the 20 replicates should be positive. Per lot, the final confirmation data set included the confirmed LoD level $(1.33 \times 10^{4} \mathrm{TCID}_{50} / \mathrm{mL})$ with at least one additional level tested above and below this value to demonstrate that levels above the LoD were $100\%$ positive and levels below the LoD were $< 95\%$ positive. The results are summarized below in Table 6. K233842 - Page 12 of 19 {12} Table 6: Confirmatory LoD Study Summary | Concentration of SARS CoV-2 applied to dry swab | Lot 2023104 Positive/ Tested | Lot 2023105 Positive/ Tested | Lot 2023106 Positive/ Tested | | --- | --- | --- | --- | | 3.98 x 10^{4} TCID_{50}/mL (Preliminary LoD) | 20/20 | 20/20 | 20/20 | | 1.33 x 10^{4} TCID_{50}/mL (Confirmed LoD) | 20/20 | 20/20 | 19/20 | | 4.43 x 10^{3} TCID_{50}/mL (0.3x LoD) | 15/20 | 17/20 | 16/20 | The limit of detection for the iHealth COVID-19 Antigen Rapid Test using SARS-CoV-2 strain hCoV-19/South Africa/CERI-KRISP-K040013/2022, was confirmed to be 1.33 x 10⁴ TCID₅₀/mL (6.65 x 10² TCID₅₀/swab) with all three tested lots. ## b. WHO Standard for SARS-CoV-2 Antigen (NIBSC 21/368) A study was performed to also determine the Limit of Detection (LoD) for iHealth COVID-19 Antigen Rapid Test in ANS samples using the WHO International Standard for SARS-CoV-2 Antigen (NIBSC 21/368) as a standardized material. As per the WHO instructions, the international standard material was reconstituted in 0.25 mL of ultra-pure water. Following reconstitution, the ampule was left at ambient temperature for 20 minutes and then mixed thoroughly, avoiding generation of excess foam. The reconstitution of the material yielded a final stock concentration equal to 2.0 x 10⁴ IU/mL. This sample was diluted 1:5 to yield a concentration of 4.0 x 10³ IU/mL. ## Range Finding LoD Study A preliminary LoD concentration was determined by testing two series of 2-fold dilutions of the 4.0 x 10³ IU/mL solution spiked into negative nasal matrix (NNM) in replicates of three (3), using three test lots. Once the lowest concentration with 3 out of 3 positive replicates was established, it was considered the preliminary LoD. The results of this preliminary LoD study are shown as Table 7: Table 7: Results LoD Range Finding with WHO SARS-CoV-2 Antigen Standard | NIBSC 21/368 Concentration applied to dry swab | Positive/ Tested | | --- | --- | | Initial Range Finding | | | 4.00 x 10^{3} IU/mL | 9/9 | | 2.00 x 10^{3} IU/mL | 9/9 | | 1.00 x 10^{3} IU/mL | 9/9 | | 5.00 x 10^{2} IU/mL | 9/9 | | 2.50 x10^{2} IU/mL | 0/9 | | 2^{nd} Round Range Finding | | | 8.00 x 10^{2} IU/mL | 9/9 | | 4.00 x 10^{2} IU/mL | 9/9 | | 2.00 x 10^{2} IU/mL | 0/9 | K233842 - Page 13 of 19 {13} Confirmatory LoD Study The preliminary LoD was confirmed by testing an additional twenty (20) replicates per lot at the preliminary LoD. The results of this testing, as shown in Table 8 confirmed the Limit of Detection for the WHO International Standard Antigen to be 4.00 x 10² IU/mL and 20 IU/swab. Table 8: WHO SARS-CoV-2 Standard Confirmatory LoD Results | Concentration of WHO International Standard for SARS-CoV-2 antigen applied to dry swab | Positive/ Tested | | --- | --- | | 4.00 x 10² IU/mL | 59/60 | # 7. High Dose Hook Effect The purpose of this study was to evaluate the effect of a high concentration of SARS antigen on the performance of the iHealth COVID-19 Antigen Rapid Test. Fifty microliters (50 μl) of heat-inactivated SARS-CoV-2 (hCoV-19/South Africa/CERI-KRISP-K040013/2022 Lineage BA.5) at 3.98 x 10⁶ TCID₅₀/mL concentration (300x LoD) was added to each swab and was tested in five (5) replicates using the iHealth COVID-19 Antigen Rapid Test. The testing was conducted according to the Instructions for Use for the test. The results are summarized in Table 9 below: Table 9: High Dose Hook Effect Study Results | Concentration of SARS CoV-2 BA.5 applied to dry swab | Kit Lot 2023014 Positive/ Tested | | --- | --- | | 3.98 x 10⁶ TCID₅₀/mL | 5/5 | # 8. Inclusivity (Analytical Reactivity) Analytical reactivity for iHealth COVID-19 Antigen Rapid Test was demonstrated using 14 additional strains/isolates of SARS CoV-2 virus. Heat-inactivated SARS-CoV-2 isolates were each diluted into NNM at different concentrations. Each concentration was tested with 5 replicates until all 5 dilutions tested negative, or two consecutive dilutions produced one or more negative replicates out of 5. The reactivity of the IHealth COVID-19 Antigen Rapid Test with the variants is summarized in Table 10 below, with the lowest concentration that returned 100% positive replicates (i.e., 5/5). Table 10: Inclusivity Study Results | SARS-CoV-2 Variants | Lowest Variant Concentration with 5/5 positive replicates [TCID50/mL] | | --- | --- | | SARS-CoV-2 virus (USA-WA1/2020) | 4.57 x 10³ | | B.1.1.7 (Alpha) | 9.55 x 10³ | | B.1.351 (Beta) | 3.80 x 10³ | | P.1 (Gamma) | 1.7 x 10³ | | B.1.617.2 (Delta) | 1.26 x 10⁴ | | B.1.1.529 (Omicron) | 5.01 x 10² | | BA.2. (Omicron) | 1.0 x 10³ | | BA.2.3 (Omicron) | 1.17 x 10³ | | BA.4 (Omicron) | 6.31 x 10³ | | BA.4.6 (Omicron) | 1.00 x 10⁴ | K233842 - Page 14 of 19 {14} | SARS-CoV-2 Variants | Lowest Variant Concentration with 5/5 positive replicates [TCID50/mL] | | --- | --- | | BA.5(Omicron) | 3.98 x 10^{3} | | BQ.1(Omicron) | 2.0 x 10^{3} | | BQ.1.1(Omicron) | 7.94 x 10^{4} | | XBB (Omicron) | 1.0 x 10^{3} | 9. Assay Cut-Off: Not applicable, the device is a binary qualitative assay. B. Comparison Studies: 1. Method Comparison with Predicate Device: Not applicable. See “C. Clinical Studies.” for performance comparison with a clinical comparator. 2. Matrix Comparison: The iHealth COVID-19 Antigen Rapid Test is only intended for the qualitative detection of the nucleocapsid protein antigen from SARS-CoV-2 in direct anterior nasal swab specimens. As no other specimen or sample type is claimed for this device, a Matrix Comparison study is not applicable. C. Clinical Studies: 1. Clinical Sensitivity and Specificity: The performance of the iHealth COVID-19 Antigen Rapid Test was compared to the sample results as generated by a highly sensitive EUA authorized molecular SARS-CoV-2 RT-PCR assay with an extraction step. A prospective clinical study was conducted from December 2022 to February 2023. Twenty-four clinical sites across 4 U.S. states participated in the study and enrolled symptomatic patients within 7 days of symptom onset (DPSO). Anterior nasal swab samples for the investigational device were either self-collected by a lay user aged $\geq 15$ years or collected by an adult (parent/guardian) from individuals aged 2 - $< 14$ years and were processed by the lay user per the IFU of the proposed device. A nasopharyngeal (NP) swab was collected from patients by a healthcare professional at the clinical study sites who inserted the swab into a tube containing Viral Transport Medium for RT-PCR comparator testing. The order of swab collection for investigational and comparator testing was randomized via a number sequence provided to each study site. A total of 968 eligible subjects were enrolled in this study, 835 subjects (age $\geq 14$ years old) and 133 subjects ages 2 - 13 years. Detailed study subject demographics are given below in Table 11: K233842 - Page 15 of 19 {15} Table 11: Study Demographics, Total Eligible Subjects | Age group | Percent total | Total | | --- | --- | --- | | 2-13 years | 13.7% | 133 | | 14-24 years | 15.3% | 148 | | 25-64 years | 68.2% | 660 | | ≥65 years | 2.8% | 27 | | Total | 100% | 968 | | Education | Number | Total | | --- | --- | --- | | High School or lower | 483 | 49.9% | | Associate degree | 152 | 15.7% | | Bachelors | 249 | 25.7% | | Graduate Degree | 84 | 8.7% | | Total | 968 | 100% | The clinical study included about $10\%$ low positive samples as defined by the comparator's mean Ct value at the comparator's LoD. With clinical samples collected within 6 DPSO, the iHealth COVID-19 Antigen Rapid Test had a Positive Percent Agreement (PPA) of $88.9\%$ and Negative Percent Agreement (NPA) of $99.9\%$ when compared to the result of the SARS-CoV-2 RT-PCR comparator assay. The study results are described in Table 12 below. PPA estimates and the number of positives samples stratified by DPSO are provided in Table 13. Table 12: Clinical Study Results for iHealth COVID-19 Antigen Test:1-6 DPSO | iHealth COVID-19 Antigen Rapid Test | EUA RT-PCR Comparator | | | | --- | --- | --- | --- | | | Positive | Negative | Total | | Positive | 104 | 1b | 105 | | Negative | 13a | 797 | 810 | | Total | 117 | 798 | 915 | | Positive Percent Agreement (PPA) | 88.9% (104/117) (95%CI: 81.9% - 93.4%) | | | | Negative Percent Agreement (NPA) | 99.9% (797/798) (95%CI: 99.3% - 100%) | | | a) Of the 13 false negatives, 12/13 were positive on a $2^{\mathrm{nd}}$ EUA RT-PCR Assay b) The 1 false positive was positive on a $2^{\mathrm{nd}}$ EUA RT-PCR Assay Table 13: PPA Values Stratified by DPSO | Days Post Symptom Onset | iHealth Positives/Total Positives | PPA | 95% CI | | --- | --- | --- | --- | | 1 | 2/4 | 50.0 % | 15.0%-85.0% | | 2 | 32/32 | 100 % | 89.0%-100% | | 3 | 34/37 | 91.9 % | 78.7%-98.2% | | 4 | 22/25 | 88.0 % | 70.0%-95.8% | | 5 | 9/12 | 75.0 % | 46.7%-91.1% | | 6 | 5/7 | 71.4 % | 35.9%-91.7% | | Total | (104/117) | 88.9% | 81.9% -93.4% | K233842 - Page 16 of 19 {16} D. Clinical Cut-Off: There is no clinical cut-off for this device. This section is therefore not applicable. E. Expected Values/Reference Range: A patient sample is expected to be negative for SARS-CoV-2. F. Other Supportive Performance Characteristics Data 1. Flex Studies To assess the robustness of the iHealth COVID-19 Antigen Rapid Test, flex studies were conducted that assessed all major aspects of the test procedure (e.g., swab extraction time, drops of sample added to test cassette, development time, delay in sample analysis, swab agitation, sample buffer agitation) and variability of environmental test conditions that the test may be subjected to when in use (e.g., various temperature and humidity stress, cassette disturbance, sample/reagent temperature, lighting). Testing was performed with contrived positive nasal swabs prepared by diluting heat inactivated SARS-CoV-2 virus into negative clinical nasal swab matrix at 2x LoD. The studies support that the test is robust in the intended use condition with an insignificant risk of erroneous result. 2. Usability Study The design and instructions for use of the iHealth COVID-19 Antigen Rapid Test are very similar to the EUA version of the test authorized in EUA210470, for which a human factors usability study was performed on the critical tasks defined by the major operational steps of the testing procedure per IFU. In this study all users completed all critical tasks with a greater than 95% reliability. The minor changes in design and Instructions for Use do not significantly affect how the user interacts with the test and are not likely to impact usability or performance of this test. Therefore, an additional usability study was not performed in support of this 510(k). 3. Lay-User Readability The purpose of this study was to determine whether lay users can interpret test results correctly with low positive samples from the iHealth COVID-19 Antigen Rapid Test. The study was conducted according to an IRB approved Lay User Readability Study Protocol in a simulated home environment. A total of 58 lay users with diverse gender, ages, and educational background, and who met the study inclusion criteria, were enrolled for the Readability Study. Each lay user was asked to interpret four test devices with three different concentrations, prepared with recombinant SARS CoV-2 nucleoprotein that were arranged in a randomized and blinded test panel as listed below, for a total of 85 negative devices, 89 low positive devices, and 58 positive devices: - Negative, 1.5xLoD, 1.5xLoD, 6xLoD - Negative, Negative, 1.5xLoD, 6xLoD 50% of the study participants were male and 50% of the study participants were female. 69% of individuals were vision impaired, and about 14% of individuals were either still at high school or K233842 - Page 17 of 19 {17} had a high school degree as their highest level of education. The demographics and age distribution of the study are shown in Table 14 and the vison impairment status in Table 15. The results of the study, stratified by age and overall are shown in Table 16. Negative samples, 1.5x LoD samples with concentrations at 6x LoD were all correctly interpreted by all lay users in the study. Table 14: Lay User Readability - Demographics and Age Distribution | Age group | Number of lay users | Percentage | | --- | --- | --- | | 15-19 years | 5 | 8.6% | | 20-30 years | 15 | 25.9% | | 31-50 years | 23 | 39.7% | | 51-55 years | 2 | 3.4% | | >55 years | 13 | 22.4 | | | | | | Total | 58 | 100% | | Education | Lay user | Total | | --- | --- | --- | | Some High School | 5 | 8.6% | | High School | 3 | 5.2% | | Some College | 4 | 6.9% | | College | 17 | 29.3% | | Some Grad School | 1 | 1.7% | | Grad School | 28 | 48.2% | | Total | 58 | 100% | Table 15: Lay User Readability - Vision Impairment of Lay Users | Type of Vision Impairment | Percentage of Total Study Cohort | | --- | --- | | Near sightedness only | 50% (29/58) | | Far sightedness only | 12% (7/58) | | Near sightedness & Far sightedness | 3.4% (2/58) | | Color Blindness | 1.7% (1/58) | | Reading | 1.7% (1/58) | | Total lay users with vision impairment | 69% (40/58) | Table 16: Readability Study - Results Stratified by Age and Overall | Age group | Sample Concentrations | | | Correct/Total* | | --- | --- | --- | --- | --- | | | Correct/ Negative | Correct/ Low Positive (1.5xLoD) | Correct/ Positive (6xLoD) | | | 15-19 years | 8/8 | 7/7 | 5/5 | 20/20 | | 20-30 years | 23/23 | 22/22 | 15/15 | 60/60 | | 31-50 years | 32/32 | 37/37 | 23/23 | 92/92 | | 51-55 years | 3/3 | 3/3 | 2/2 | 8/8 | | >55 years | 19/19 | 20/20 | 13/13 | 52/52 | | Total | 85/85 | 89/89 | 58/58 | 232/232 | K233842 - Page 18 of 19 {18} | Age group | Sample Concentrations | | | Correct/Total* | | --- | --- | --- | --- | --- | | | Correct/Negative | Correct/Low Positive (1.5xLoD) | Correct/Positive (6xLoD) | | | Negative Agreement | 100% (85/85)* | n/a | n/a | 100% (85/85)* (95%CI: 96%-100%) | | Low Positive (1.5xLoD) Agreement | n/a | 100% (89/89)* | n/a | 100% (89/89)* (95%CI: 96%-100%) | | Positive (6xLoD) Agreement | n/a | n/a | 100% (58/58) | 100% (58/58)* (95%CI: 94%-100%) | *Based on the randomized panels assigned to study participants, 85 negative devices, 89 low positive devices, and 58 positive devices were tested in the study ## VIII. Proposed Labeling: The labeling supports the finding of substantial equivalence for this device. ## IX. Conclusion: The submitted information in this premarket notification is complete and supports a substantial equivalence decision. K233842 - Page 19 of 19