Further, some recent studies also have sparked questions about coronavirus immunity. For example, results from a study recently released in preprint that hasn't yet been peer reviewed showed that antibodies developed against the coronavirus in people who'd been infected declined significantly within two to three months post infection.
Moreover, Elitza Theel, director of the infectious diseases serology laboratory at the Mayo Clinic
who was not involved in the study, said researchers are finding that coronavirus "antibodies will peak at about 20 to 30 days after symptom onset, and then they decline," and "[t]hey seem to decline much more rapidly in individuals that were asymptomatic or had mild forms of the disease."
Given that antibodies help to neutralize the coronavirus and are believed to provide people with immunity against the pathogen, those findings have raised alarms among some observers that people may gain natural immunity to the coronavirus for only a few months. https://www.advisory.com/daily-briefing/2020/07/24/covid-reinfection
Sherry Wellman, 56, of Youngstown, Ohio, and her doctors had assumed it would last longer than two months.
Image: Sherry Wellman
Sherry Wellman.Courtesy Sherry Wellman
After an initial positive test for the virus in March, two additional COVID-19 tests in April were negative. It was welcome news to Wellman, whose job as a nurse required her to have two negative tests before returning to work.
But a month later, she had to go to the hospital for chest pains, and was tested again.
The physicians "ended up testing me for COVID just for the heck of it," Wellman said. "Sure enough, it came back positive. They were stunned."
"The nightmare of this is based on how much we don't know," Saag said. "COVID is brand new. We're discovering as we go." A growing pool of data, he said, suggests COVID-19 antibodies wane about 60 to 90 days after infection.
Shelby Hedgecock, 29,
a wellness coach in Los Angeles, has had a similar experience: positive COVID-19 tests in April, followed by two negative tests in May, and then another positive test.
The first would be the concept of herd immunity. "Just throw it out the window,"
Saag said. "Because not enough people could sustain an immune response that would protect against reinfection long enough for the virus to extinguish."
The second involves vaccine development. If natural infection cannot provide lasting protection against the virus, experts said, a vaccine produced in the lab may not either.https://www.nbcnews.com/health/health-news/i-cannot-get-again-it-possible-get-reinfected-coronavirus-n1233667Hopes are dimming that "herd immunity" can help stamp out the tenacious global pandemic amid growing concerns that people can be reinfected with COVID-19. https://www.usatoday.com/story/news/health/2020/07/16/covid-19-can-you-get-infected-twice-herd-immunity/5429012002/
The jury is still out. Links could be posted that say it is unlikely. But they simply do not know.