New studies indicate that people who survive COVID-19 may not retain immunity from it for long afterward — perhaps as little as one month. Experts have been scrambling for data on coronavirus antibodies, which not only protect survivors from re-infection but could be used to manufacture treatments and drugs. According to a new study conducted in China and published in the journal PLOS Pathogens, that route may not be very fruitful.
Researchers measured the level of antibodies in the blood of coronavirus survivors periodically after they were cleared of the infection to get the results of this new study, according to a report by The Daily Mail. They found that the level of antibodies tend to "decline significantly" within the first four weeks after the patients left the hospital. The study tracked the immune responses of 19 patients with non-sever cases of COVID-19 and seven people with severe cases of it. Out of those 26 people, only 21 had antibodies in the first place.
Even those that had antibodies did not necessarily have enough to neutralize the virus, researchers found. They said that a "small portion" of patients had enough antibodies to fend off the virus, but even those declined fast. After four weeks, these patients faced the risk of re-infection as well.
The scientists did not draw definitive conclusions from their data, but it does not bode well for future studies. This news comes amid a growing number of reports from around the world about people getting re-infected with COVID-19, having already survived it once. More and more of these stories are being deemed "credible" by the scientific community.
Not only does this study question the immunity of COVID-19 survivors, it casts doubt on the processes for developing a working vaccine. Natural antibodies are vital for scientists working on a long-term vaccine of any kind, but if these deteriorate quickly, such a vaccine might not be possible.
"The development of antibody response to Sars-CoV-2, the virus that causes Covid-19, started to be reported but remained largely elusive," the authors of the new study wrote. "Understanding the adaptive responses where the body makes antibodies that specifically bind to the Sars-CoV-2 among Covid-19 patients provides fundamental information for developing effective treatment and preventive vaccine."
Asked about this study, immunology professor Danny Altmann noted that it is "a vital part of the 'work-in-progress' to make sense of who has immunity and for how long." He added: "We don't know to what extent this is bad news unless we know the extent to which the white blood cells that make the antibody (B cells) are up and ready to defend against any repeat attack."