COVID infection can boost antibodies for up to 20 months | Health info

MONDAY, Feb. 7, 2022 (HealthDay News) — If you’ve had COVID-19 before, your natural antibodies can last up to 20 months, according to a new study.

While that’s reassuring, experts are quick to warn that new findings don’t necessarily mean you’re protected from reinfection, and vaccines remain an important part of a COVID-19 prevention strategy.

“This study tells us that people have antibodies hanging around after COVID-19, but that tells us nothing about immunity because we don’t know what level of natural antibodies are needed for protection,” said Dr Otto Yang. . immunologist from the David Geffen School of Medicine at the University of California, Los Angeles, who reviewed the results: “People can and do get reinfected when they have natural antibodies against COVID-19.”

For the study, the researchers measured antibody levels in the blood of 816 unvaccinated American adults. Investigators found antibodies in 99% of those who said they had a positive COVID-19 test result; 55% of people who thought they had COVID-19 but were never tested; and 11% who did not think they had ever had COVID-19.

“Nearly everyone with documented COVID-19 infection had antibodies, and those antibodies seem to persist for quite a long time,” said study author Dr. Dorry Segev, a transplant surgeon at Johns Hopkins University. , in Baltimore. “We really need to start incorporating natural immunity antibodies into the context of immunity assessment, moving from vaccine testing to immunity testing.”

“There is certainly evidence that antibody levels correlate with … clinical protection, and the same caveats for natural immunity are there for vaccine immunity,” he said.

Other studies have shown that natural antibodies against COVID-19 are declining over time, often in about six months, Yang noted. The new study looked at data on a group of people at a given time. Studies that follow the same people at multiple points in time have shown that natural antibodies drop, Yang added.

Crucially, just because you have natural antibodies doesn’t mean you’re protected against reinfection, pointed out Dr. Len Horovitz, a pulmonologist at Lenox Hill Hospital in New York.

“Antibodies can last in your blood for months, but we don’t know how much protection you need to be,” said Horovitz, who was not involved in the new study.

People who have had more severe COVID-19 illness have higher antibody levels, but that doesn’t protect them forever, he noted.

“If you’ve survived COVID-19, you have some cell-mediated immunity, but that’s different from the kind of immunity and antibodies you get from the vaccine, and it’s ideal to have both,” Horovitz said.

Antibodies against the SARS-CoV-2 nucleocapsid protein only appear if you have recovered from COVID, he explained, while vaccines and natural infection produce antibody against the spike proteins of the virus.

Do everything you can to protect yourself from COVID-19, he urged.

“Get vaccinated and boosted when you can, wear masks in public places, practice social distancing, and stay home when you’re sick,” Horovitz said.

SOURCES: Otto Yang, MD, immunologist, David Geffen School of Medicine, University of California, Los Angeles; Dorry Segev, MD, PhD, transplant surgeon and professor, Johns Hopkins University, Baltimore; Len Horovitz, MD, pulmonologist, Lenox Hill Hospital, New York; Journal of the American Medical Association, Feb. 3, 2022, online

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