Determining Immune Status

With each passing day, it feels as if there are more questions than answers. This is partly because there is still so much we don’t know about this strain of the novel coronavirus, SARS-CoV-2. When infected, recovery for mild cases can take 1 week to 2 weeks, but more severe cases can take longer than 6 weeks.¹ As many states are in their fourth to sixth week of stay-at-home orders and others are beginning to reopen some businesses, there has been a shift in the discussion regarding whether those previously infected now have immunity.

When people get sick, their bodies sense a foreign substance that triggers the immune system to develop antibodies against it. When the body encounters that same foreign substance in the future, the hope is that the antibodies can then easily fight it off, which we call immunity. As we are starting to see more people recovering from the virus, they are now being tested to see if they have antibodies against SARS-CoV-2. If they come back positive for antibodies, these individuals should be considered immune to future infections from this virus. However, the World Health Organization (WHO) warns there is no evidence that suggests individuals recovering from COVID-19 are, in fact, protected from a second infection, even with a positive antibody test²

One of the reasons for skepticism is that many people who have recovered are showing very low levels of neutralizing antibodies.² The accuracy and reliability of laboratory testing are other areas of concern. Without validity, tests can come back with false positives—a patient with a positive test but who is actually negative for antibodies—and false negatives-—a patient with a negative test who is positive for antibodies. One of the reasons this may happen is the sensitivity of the test to other similar coronaviruses.² The antibodies to other coronaviruses can cross-react with antibodies produced in response to SARS-CoV-2.²

As such, the National Institutes of Health (NIH) and the Foundation for the NIH (FNIH) are collaborating with private biopharmaceutical companies and government agencies, including the United States Centers for Disease Control and Prevention (CDC) and US Food and Drug Administration (FDA). The goal of this partnership is to prioritize finding a vaccine while also streamlining clinical trials and coordinating regulatory processes in order to effectively respond to COVID-19.³

The National Institute of Allergy and Infectious Diseases (NIAID) has also put a four-tiered strategic plan in place, which lays out their research priorities for the immediate future. The first part of the plan involves compiling more data on the virus itself: how it is transmitted and why symptoms present as mild for some while others become critically ill. The second tier involves finding a more accurate and rapid diagnostic tool for diagnostic testing and testing for antibodies. The third involves testing potential treatments for COVID-19, while the fourth tier involves research to develop a safe and effective vaccine to protect against future coronavirus infections.⁴

As most of us sit at home wondering when things will get back to normal, it’s good to know these organizations are working to combat this virus. However, as the CDC, NIAID, WHO, and others have already discussed, it could take months or longer for us to fully understand SARS-CoV-2.

References

1. Maragakis L. I’ve been diagnosed with the new Coronavirus (COVID-19). Available at: https://www.hopkinsmedicine.org/health/conditions-and-diseases/coronavirus/diagnosed-with-covid-19-what-to-expect
2. World Health Organization. “Immunity passports” in the context of COVID-19. Available at: https://www.who.int/news-room/commentaries/detail/immunity-passports-in-the-context-of-covid-19
3. National Institutes of Health. NIH to launch public-private partnership to speed COVID-19 vaccine and treatment options. Available at: https://www.nih.gov/news-events/news-releases/nih-launch-public-private-partnership-speed-covid-19-vaccine-treatment-options
4. National Institutes of Health. NIAID strategic plan details COVID-19 research priorities. Available at: https://www.nih.gov/news-events/news-releases/niaid-strategic-plan-details-covid-19-research-priorities