One shot may be enough for COVID-19 survivors

For people who have bared their arms for a two-dose COVID-19 vaccine, the message from public health officials has been clear: Get the second shot if you want full protection.

But an emerging body of evidence suggests there may be an exception to that rule. If you’ve already battled a coronavirus infection, it’s possible that one dose may suffice.

Both the Pfizer-BioNTech and Moderna vaccines require two doses given weeks apart. The first dose essentially primes the immune system to recognize and attack the virus’s telltale spike protein, while the second one prompts the immune system to produce a flood of antibodies. Getting that second dose is essential in order to get the fullest possible protection against the virus, experts say.

However, a study by scientists in Seattle and Montreal found that in the COVID-19 survivors, a single dose of vaccine boosted antibody levels against several different coronavirus variants by up to a thousandfold — and that a second dose essentially offered no additional benefit.

In another recent study, researchers in New York found that after just one shot, those who had already been infected had antibody levels that were 10 to 45 times higher than those whose histories were infectionfree.

Dr. Francis Collins, director of the National Institutes of Health, said “much more research is needed — and I am definitely not suggesting a change in the current recommendations right now.”