A fourth dose of the Pfizer-BioNTech vaccine is effective in reducing the short-term risk for COVID-19 infection, hospitalization, and death in people who got a third dose at least 4 months before, a large study shows.
However, Paul Offit, MD, author of an editorial accompanying the study, told this news organization, “I would argue, without fear of contradiction, that this is going to have no impact on this pandemic.”
“We are still in the midst of a zero-tolerance policy for this virus. We don’t accept mild illness and if we’re not going to accept mild illness, we think we have to boost it away, which would mean probably about two doses every year. That’s not a reasonable public health strategy,” said Dr. Offit, director of the Vaccine Education Center at the Children’s Hospital of Philadelphia.
Booster confusion
Results of the research out of Israel, published in the New England Journal of Medicine, make a case for a fourth booster for people 60 and over.
Researchers, led by Ori Magen, MD, Clalit Research Institute, innovation division, Clalit Health Services, Tel Aviv, analyzed data comparing 182,122 matched pairs recorded by the largest health care organization in Israel from Jan. 3 to Feb. 18, 2022. With more than 4.7 million members, Clalit Health Services covers more than half of the population of Israel.
The researchers compared outcomes in people 60 or older (average age, 72 years) who got a fourth dose with outcomes in those who had only a third dose. They individually matched people from the two groups, considering factors such as age, health status, and ethnicity.
Relative vaccine effectiveness in days 7-30 after the fourth dose was estimated to be 45% (95% confidence interval, 44%-47%) against confirmed SARS-CoV-2 infection, 55% (95% CI, 53%-58%) against symptomatic COVID-19, 68% (95% CI, 59%-74%) against hospitalization, 62% (95% CI, 50%-74%) against severe COVID, and 74% (95% CI, 50%-90%) against COVID-related death.
Several countries, including the United States, have begun offering a fourth vaccine dose for higher-risk populations in light of evidence of waning immunity after the third dose and waves of infection, driven by Omicron and its variants, in some parts of the world. But the recommended age groups differ considerably.
In the United States, for instance, the Food and Drug Administration in late March approved a fourth dose of the Pfizer or Moderna vaccine for anyone over 50 and people over 18 who have gotten a solid organ transplant or have a similar level of immune risk.
Dr. Offit pointed out that Israel offers the fourth vaccine for people 60 and over and the European Medical Association offers it for those over 80. No surprise that confusion over the fourth dose is rampant.
Booster advice
Dr. Offit offered this perspective: People who are immunocompromised could reasonably get a fourth dose, depending on the manner in which they are compromised.
“Someone who has a solid organ transplant is not the same as someone who is getting a monoclonal antibody for their rheumatoid arthritis,” Dr. Offit said, adding that people could also make a reasonable argument for the fourth dose if they are over 65 and have multiple comorbidities.
“I’m over 65,” Dr. Offit said. “I’m generally healthy. I’m not going to get a fourth dose.”
People with multiple comorbidities over age 12 could reasonably get a third dose, he said. “For everybody else – healthy people less than 65 – I would argue this is a two-dose vaccine.”
CHOP, he noted as an example, mandates the vaccine but doesn’t mandate three doses and he says that’s not unusual for hospital systems.
“How many lives are you really saving with that fourth dose? If you really want to have an effect on this pandemic, vaccinate the unvaccinated,” Dr. Offit said.