Since the start of the coronavirus pandemic, scientists and doctors have been working day and night to find ways to combat the global crisis. One of those solutions has been developing an antibody test to determine whether or not you’ve been exposed to COVID-19. But the question remains: If you have been exposed, does that mean you’re immune from catching it again?
Knowing whether survivors are now immune is essential, because it will dictate how and when communities can start to resume their normal lives. If people who have recovered from coronavirus are now immune, they may be able to safely go back to work, for example.
But as of now, there's no easy answer to the immunity question. Just this past week, CityMD mistakenly told 15,000 people who had tested positive for coronavirus antibodies that they were now immune to COVID-19. The statement was deemed misleading, and CityMD has since changed their messaging, according to CNBC.
In a senate hearing on 12th May, Senator Rand Paul, MD, who previously tested positive for the illness, pointedly asked Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, about coronavirus immunity. “We have no evidence that survivors of coronavirus don’t have immunity, and a great deal of evidence to suggest that they do,” the senator of Kentucky argued. "You've stated publicly that you'd bet it all that survivors of coronavirus have some form of immunity. Can you help set the record straight... that infection of coronavirus likely leads to some form of immunity?" he asked Dr Fauci.
"Given what we know about the recovery from coronaviruses in general or even any infectious disease with very few exceptions, when you have antibodies present it very likely indicates a degree of protection," Dr Fauci replied. But, he noted, in this case, immunity has not been formally proven by long-term natural history studies. "You can make a reasonable assumption that it would protective, but natural history studies over a period of months to years will then definitively tell you if that's the case," explained Dr Fauci.
Dr Fauci also said that as of now, we don't know what antibody titre (a measurement of how much antibody an organism produces) is required for a person to be considered immune. We also don't know how long immunity would persist after recovery.
What's more, the SARS-CoV-2 virus, which causes COVID-19, may mutate over time, according to scientists at the Los Alamos National Laboratory. If that were true, people who recovered could potentially be vulnerable to catching a newly mutated strain again. The researchers released a paper that claimed to reveal “the emergence of a more transmissible form” of the virus. But those conclusions were called "overblown" by Lisa Gralinski of the University of North Carolina, one of the few scientists in the world who specialises in coronaviruses, in an interview with The Atlantic.
Another reason experts are hesitating: The antibody test is far from perfect. If a person's test comes back positive for the presence of coronavirus antibodies, there's still a 10 to 30% chance that they may be from another cold or infection, not COVID-19 in particular, Shawn Nasseri, MD, who practices in Beverly Hills, previously told Refinery29.
Even if the antibodies detected are from COVID-19, as Dr Fauci pointed out, we don't know if they're present in high enough levels to offer immunity. "There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection," the World Health Organization reports.
"As we see larger numbers of people, then we will have a better understanding of the patients who show strong immunity and statistics reflecting that they are not getting the virus," said Dr Nasseri in a follow-up interview with Refinery29. "I would say we have at least a couple more months before we have adequate data."
To sum up: If you've had coronavirus in the past, it's likely you do have some immunity to it now. But it's not certain, so until we know more, everyone should still be following the CDC's guidelines for social distancing, wearing masks, and monitoring symptoms.