This study aim to evaluate the immune response of negative patients during a COVID-19
outbreak in patients with no symptoms and with no known exposure to the COVID-19.

Patients are tested with a VivaDiag ™ COVID-19 lgM / IgG Rapid Test at day 0, day 7 and day
14. The investigators expect test to be negative on all the measurements in those patients
that do not develop symptoms and that continue to have no known history of exposure to
COVID-19

Patients that develop symptoms (cough, fever or respiratory distress) and a possible contact
with people positive for COVID-19 OR patients that show a positive VivaDiag test during the
time frame of the test are asked to attend the COVID-19 RT - PCR &CT.

Subsequently, the investigators will continue, repeating two tests seven days apart every 30
days (predefined times 0-7-14, then 30-37, 60-67) for the next six months. The investigators
can evaluate to stop the test however before the six months if there are no new cases of
COVID-19 for at least 21 days in the region where the enrolled patients live.

The test in use is the VivaDiag ™ COVID-19 lgM / IgG

Procedure (as per the protocol in use for the administration of the test)

1. take out the test kit and leave it at least 30 minutes in the room where the test will
be performed.

2. place the test equipment on a clean and dust-free surface

3. First insert 10µL of whole blood or serum or plasma in the area reserved for blood (in
the well) present on the test, then apply 2 drops of buffer.

4. read the result after 15 minutes

Interpretation of test results

Positive result

1. The anti-COVID-19 lgM antibody is detected if: the quality control band C and the lgM
band are both colored and the lgG band does not stain. This means that the anti-COVID-19
lgM antibody is positive.

2. The anti-COVID-19 lgG antibody is detected if: the quality control band C and the lgG
band are both colored and the lgM band does not stain. This means that the COVID-19 lgG
antibody is positive.

3. The lgG and lgM anti-COVID-19 antibodies are detected if: the C band, the lgG band and
the lgM band are all three colored. This means that the anti-COVID-19 lgG and lgM
antibodies are both positive.

Negative result The anti-COVID-19 lgG and lgM antibodies are not detected if only the quality
control C band is stained but the lgG and lgM bands are not colored, this means that the test
is negative.

Invalid result

If the quality control band C does not color, regardless of whether the lgG and lgM bands are
colored or not, the result is invalid and the test must be started again.

Specs of the test

Product Name VivaDiag™ COVID-19 IgM/IgG Rapid Test Test Principle Colloidal gold Sample Type
Whole blood (from vein or fingertip), serum or plasma Sample Volume 10 μL Test Time 15 min
Operation Temperature 18-25ºC Storage Temperature 2-30ºC Shelf Life (Unopened) 12 months