Correction Note:
Due to a math miscalculation in the study, a previous version of this release contained an error in the rate at which COVID-19 antibodies decline after infection. The correct rate is 36 days, not 73 as previously reported, which is actually a more dramatic rate of decay. The change is reflected under the findings section of the release.
FINDINGS
A study by UCLA researchers shows that in people with mild cases of COVID-19, antibodies against SARS-CoV-2 -- the virus that causes the disease -- drop sharply over the first three months after infection, decreasing by roughly half every 36 days on average. If sustained at that rate, the antibodies would disappear within about a year.
BACKGROUND
Previous reports have suggested that antibodies against the novel coronavirus are short-lived, but the rate at which they decrease has not been carefully defined. This is the first study to carefully estimate the rate at which the antibodies disappear.
METHOD
The researchers studied 20 women and 14 men who recovered from mild cases of COVID-19. Antibody tests were conducted at an average of 36 days and 82 days after the initial symptoms of infection.
IMPACT
The findings raise concerns about antibody-based "immunity passports," the potential for herd immunity and the reliability of antibody tests for estimating past infections. In addition, the findings may have implications for the durability of antibody-based vaccines.