If you already had COVID, do you need the COVID vaccine?
More than 15 million Americans have been infected by the COVID-19 virus, and many may be questioning whether they need to receive one of the two coronavirus vaccines now on the verge of approval from U.S. regulators.
Short answer: Yes.
"They will be asked to stand in line and get a vaccine also," said Dr. William Schaffner, a professor of infectious diseases at Vanderbilt University Medical Center in Nashville, Tenn. "There will be no distinction made, in part because we think there's no adverse event that will occur, and also the protection from the vaccine actually may be more long-lived, of longer duration than that you get from the natural infection."
Coronaviruses are notorious for prompting a flawed and incomplete immune response in humans, infectious disease experts say.
It's one reason why science has yet to come up with a cure for the common cold.
"With the four seasonal beta coronaviruses that circulate and cause all the upper respiratory infections you see in your practice, those people lose immunity in months to a year or two," said Dr. Gregory Poland, director of the Vaccine Research Group at the Mayo Clinic in Rochester, Minn. "That's why people fall prey to the common cold again and again."
The body uses a relatively simple strategy to fight off common cold coronaviruses, and this strategy does not appear to make a lasting impression on immune system memory, Poland said.
There's a chance that people who have had asymptomatic or mild cases of COVID-19 did not build up any lasting immunity. In fact, it's even unclear at this point what sort of immunity is conferred by severe or life-threatening cases.
"While natural infection does provide protection for some period of time, it is somewhat unpredictable how robust that response is in individuals," said Dr. Amesh Adalja, a senior scholar with the Johns Hopkins Center for Health Security, in Baltimore.
A recent COVID-19 infection could put a person a bit farther back in line for the vaccine, however.
"It is true that those who had a recent infection—within 90 days—should be behind those who hadn't," Adalja said, noting recommendations from the Vaccine Advisory Committee for the U.S. Centers for Disease Control and Prevention.
More threatening coronavirus diseases like SARS (severe acute respiratory syndrome) and MERS (Middle East respiratory syndrome) appear to produce immunity that lasts longer, but the data is limited because both viruses have infected far fewer people than the COVID-19 pathogen, experts said.
COVID-19 patients shouldn't feel as though they're getting nothing from the vaccine, Adalja added.
"In those that have recovered, the vaccine will boost natural immunity and it will be more effective at preventing disease," he said.
The clinical trials for both the Pfizer-BioNTech and Moderna vaccines are expected to provide more insight into their benefit for previously infected patients as participants continue to be monitored over coming months and years, Adalja said. The trials included some people who had already been infected.
"This is an active area of study and the vaccine trials will be analyzed in detail to see how the vaccine impacted natural immunity, as 10% of those in the trials had prior infection," Adalja said.
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