Product Manual
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Sofia SARS Antigen FIA Page 16 of 22
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The letter of authorization refers to “authorized laboratories” as: “Laboratories certified under the Clinical Laboratory
Improvement Amendments of 1988 (CLIA), 42 U.S.C. §263a, that meet the requirements to perform high, moderate, or
waived complexity tests. This test is authorized for use at the Point of Care (POC), i.e., in patient care settings operating
under a CLIA Certificate of Waiver, Certificate of Compliance, or Certificate of Accreditation.”
CLINICAL PERFORMANCE
Patient Demographics
Patient demographics (gender, age, elapsed time from date of on-set) are available for the two hundred nine
(209) samples used in the study.
The specimen positivity breakdown based on age of the patient:
Sofia SARS Antigen FIA (N=29)
Age
Total #
Total Positive
Prevalence
5 years
0
0
N/A
6 to 21 years
28
5
17.9%
22 to 59 years
156
22
16.0%
60 years
25
2
8.0%
The specimen positivity based on days post onset:
Days Post Symptom Onset
# Specimens Tested
# Positive Specimens
% Positive
0
9
0
0
1
32
5
15.6%
2*
61
11
18.0%
3
39
3
7.7%
4
24
5
20.8%
5
16
2
12.5%
6
11
2
18.2%
7
17
1
5.9%
* One specimen was Sofia SARS Antigen FIA Negative and Positive by Reference Extracted RT-PCR
A study of two hundred nine (209) direct anterior nasal swabs was performed. The samples were sequentially
enrolled from symptomatic patients suspected of COVID-19 at five (5) locations and tested fresh at a single
central laboratory. All patients had either a NP swab (for RT-PCR testing) and direct anterior nasal swab (for
Sofia testing) or matched nasal swabs collected for RT-PCR and Sofia testing. The order of swab collection was
randomized between assays. The Sofia SARS Antigen FIA was compared to a Reference Extracted RT-PCR
assay. As with all antigen tests, performance may decrease as days since symptom onset increases due to
lower viral loads later in the patient’s disease course. Similarly, the inability to synchronize asymptomatic
individuals with onset of infection may impact performance as specimens may be tested when viral loads are
below the assay’s limit of detection. Clinical studies in asymptomatic patients undergoing serial testing are
ongoing to establish the clinical performance.