New research has identified a group of Covid-19 patients who are capable of speedy recoveries and can produce protective antibodies for months after their initial infection, a finding that runs counter to a lot of recent research showing that antibody levels — and, potentially, immunity — rapidly decline following infection and points to the possibility that some people have immune systems that are better able to fight the virus.
Researchers, led by a team at Brigham and Women’s Hospital, found that almost one in five coronavirus patients sustained antibody production for several months after infection, in contrast with other patients who experienced a rapid decline in antibody levels.
These patients also tended to recover faster than other Covid-19 patients, cutting their recovery time by about a third, as well as showing differences in two types of immune cell that play key roles in the immune system, the researchers wrote in Cell, a top scientific journal.
It is unclear whether the findings are representative of the population as a whole, and the researchers themselves stressed that future investigations must look beyond the limited demographic they studied, with most volunteers being adult white women with mild Covid-19.
Dr. Duane Wesermann, one of the researchers and an associate professor at Harvard Medical School, said the immune response of these quick healers was like an insurance policy — “it’s the immune system’s way of adding a potential layer of protection against future encounters with the virus,” he said.
Wesermann added that it was possible the findings “point to a type of immune response” that is better at dealing with Covid-19, which could be important in the fight to control the virus.
It is unclear whether the findings are representative of the population as a whole, and the researchers themselves stressed that future investigations must look beyond the limited demographic they studied, which was primarily adult white women with mild Covid-19.
Understanding how the immune system responds to Covid-19 over time is a vital component in controlling the pandemic, underpinning public health measures, treatments, and how vaccines are developed and administered. A lot of early attention has focused on antibodies, proteins produced by the immune system that can lock onto the virus, with research generally showing sharp declines following infection. These are relatively easy to study, but do not give a complete picture of the body’s immune system.
What We Don’t Know
There is a lot that remains unknown about how immunity to Covid-19 works and how that changes over time. To date, many studies show sharp declines in antibody levels in the months following infection, though antibodies, or the lack thereof, do not necessarily indicate immunity to infection. Reinfections, though rare, have been reported, with some reports suggesting that the second infection is worse than the first.