People should use their discretion to decide when it’s best for them to get a second COVID booster vaccine, said Rochelle Walensky, director of the US Centers for Disease Control and Prevention (CDC).
Last week, the CDC recommended a second booster dose — a fourth injection for many people — for certain immunocompromised individuals and those over 50, provided they had received their first booster dose at least four months earlier.
It followed the Food and Drug Administration (FDA) approval of a second booster dose of either Pfizer’s or Moderna’s mRNA-COVID vaccines on March 29. The vaccine improves protection against severe COVID-19 and does not pose new safety concerns.”
Speaking to NBC News, Walensky gave further guidance as to when those eligible could opt for the second booster dose.
She said that for people who have already contracted the Omicron-COVID variant in the last two or three months, the disease “has boosted their immune systems really pretty well” and that they have another two to four months until their second booster could wait.
There is also the problem that the protection of the vaccine decreases over time. Last week said Dr. Richard Better, former acting director of the CDC, told NBC that people should “give thoughtful thought” about when to get their fourth dose.
“If you’re in an area, where [COVID] is really, really low and you’re getting the refresher now and in two, three months the rate will go up, I don’t know [if] You will have the same protection as if you wait a few months. So I’d say pay attention to what’s happening on the ground. This is one of those situations where it’s really important to talk to your doctor.”
Walensky said it was a “personal assessment” for individuals.
Her comments come after data from Israel suggested the protection against a confirmed infection offered by a fourth dose of Pfizer’s vaccine “lasted briefly” – although it should be noted that protection against serious diseases did not diminish during the study period .
The researchers used data from 1.25 million people from the Israel Ministry of Health database who were aged 60 or older and who were eligible for a fourth dose between January 10 and March 2, 2022.
The people involved in the study were divided into three groups. COVID infection and severe illness were estimated from eight days after receiving a fourth dose (the fourth dose group) compared to a three-dose group and a group that had received a fourth dose three to seven days earlier (internal control group).
The researchers found that the rate of severe COVID was 3.5 times lower in the fourth week after receiving the fourth dose than in the three-dose group and that protection against severe disease was maintained in the six weeks after the fourth dose did not wear off dose.
Confirmed infection was also 2-fold lower in the four-dose group at four weeks, but “this protection diminished in later weeks,” the researchers wrote.
The study was published in The New England Journal of Medicine on Tuesday.