As countries consider widespread testing and experts debate the merits and ethics of “immunity certificates”, more and more red flags are being raised on the quality and reliability of antibody testing kits even as governments issue warnings about what rapid antibody tests can and cannot do.
Until a vaccine or a cure for COVID-19 is devised, widespread testing to identify those who have been infected and recovered, and hence developed immunity to the SARS-CoV-2 virus (at least in theory), could allow them to resume normal work and social life.
However, the evidence is far from conclusive on whether recovering from COVID-19 confers immunity, and for how long.
More immediately, countries are flagging problems with the thousands of rapid antibody testing kits that they ordered on war footing. Yesterday, April 21, 2020, the Indian government said it was investigating complaints that some antibody kits bought from China had been inaccurate, asking states to hold off on using the tests for two days until government agencies could validate the tests.
The same day, the US Food and Drug Administration (FDA) issued a safety alert for antibody tests and said, “The FDA is not aware of an antibody test that has been validated for diagnosis of SARS-CoV-2 infection.” This means, antibody tests cannot be used to diagnose whether someone has acquired a COVID-19 infection.
It went further to say that while the FDA is open to receiving applications for approval of rapid testing kits for diagnosis, “based on the underlying scientific principles of antibody tests, the FDA does not expect that an antibody test can be shown to definitively diagnose or exclude SARS-CoV-2 infection”.
Over recent press conferences and government circulars, the Indian government has also reiterated that rapid antibody tests should be used only for surveillance and not for diagnosis. Earlier, on April 8, 2020, the World Health Organization (WHO) specified that: “WHO recommends the use of these new point-of-care immunodiagnostic tests only in research settings. They should not be used in any other setting, including for clinical decision-making, until evidence supporting use for specific indications is available.”
Regarding kits being faulty, India has not specified which antibody kits are being investigated, whether Chinese or other. However, the bulk of the 84 kits approved so far by the Indian government are from Chinese companies.
The Chinese Embassy in India tweeted on April 22, 2020, that they have taken cognisance of reports concerning the quality of rapid testing kits exported by China and that “China attaches great importance to the quality of exported medical products. Will keep close communication with Indian concerned agency and provide necessary assistance.”