https://www.yahoo.com/news/covid-booster-may-lower...
A COVID-19 booster, specifically a third vaccine dose, may lower protection against getting infected with the omicron variant again for some people — and there’s a reason why, new findings suggest.
In contrast, two vaccine doses, followed by an initial omicron infection, may protect more against a second omicron infection than an extra jab, according to a preprint study published Nov. 1 to medRxiv, a server run by Yale, BMJ and Cold Spring Harbor Laboratory. This is due to a specific reaction within the immune system, researchers concluded.
Here’s what the findings mean.
“If you got infected with Omicron at any time, a third vaccine dose actually doubles your risk of reinfection compared to 2 doses only,” Dr. Daniele Focosi, who specializes in hematology and works at Pisa University Hospital in Italy, wrote on Twitter in response to the findings. “Amazing immune imprinting at work.”
The study points to immune imprinting as the reason why “three-dose vaccination was associated with reduced protection compared to that of two-dose vaccination.”
But what exactly is immune imprinting?
Fortune explains it as “a phenomenon in which an initial exposure to a virus — say, the original strain of COVID, by infection or vaccination — limits a person’s future immune response against new variants.”