Study: Prior COVID infected may not need 2 vax doses

BOSTON — The many hundreds who have passed through the Gillette Stadium COVID-19 Vaccination Clinic in the last week all leave with the same thing: an appointment to come back for a second dose. But a new study suggests that in those previously infected with the virus, a second dose may not only be unnecessary but unnecessarily uncomfortable.

Researchers at the Mount Sinai School of Medicine in New York compared antibody titers after injection of COVID-19 vaccine in those who had a prior infection with the virus and those who did not: seropositives and seronegatives. About two weeks after vaccine injection, the seropositive group’s titer was 25-times higher than the seronegative group.

Does this make the case, as the authors suggest, for skipping the second vaccine dose in the prior infected? Doctors we spoke with said absolutely not.

“We have no scientific data to back up that,” said Dr. George Abraham, the chief of medicine at St. Vincent Hospital in Worcester.

The problem Dr. Abraham and others point out is that coronavirus antibodies are not, in general, known for their longevity.

“We know well that people who have had disease may have a temporary level of antibody protection for a few weeks, maybe a couple of months,” he said.  “But thereafter it fades.”

So, essentially, those big antibody numbers could evaporate.

>>>MORE: Select CVS stores in Massachusetts to begin offering vaccinations next week

“We see this big surge in antibody level immediately post-disease but thereafter, when we measure it out over a period of time, you may not see the same levels,” Dr. Abraham said. “Or we may not even see protective levels, which would be even more worrisome.”

Dr. Robin Colgrove, a virologist at Mt. Auburn Hospital, said that, though coronavirus antibodies lack longevity in general, reinfection with COVID-19 has, so far, been rare. That could mean they are more durable than expected.

“And the implication, then, is that getting COVID-19 is pretty protective all by itself,” he said. “The expectation, then, is that vaccination would not add much to that. But it might add something to that, we don’t know.”

And that’s really the problem with altering the vaccine regimen: there is just too much unknown to say whether it’s a safe course of action. So, a singular public health message has emerged.

“People should get vaccinated whether or not they’ve had COVID-19,” Dr. Colgrove said.

And, he added, this is no time to let up on non-pharmaceutical measures to contain the virus.

“People should continue following masks, social distancing, avoiding crowds, all of that,” Dr. Colgrove said. “Even once they’re vaccinated.”

The seropositive group also suffered side effects in significantly higher numbers, including headache, fatigue, and muscle and joint pain.

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