Covid Booster and Omicron: Who should be vaccinated now?
One recent study evaluation of the bivalent coupler in individuals over 12 years of age has shown that it works equally well in individuals of all ages. The researchers compared how people fared during the three months after they received the monovalent booster (from May to August 2022) with the three months after people received the bivalent booster (from September to December 2022). They found that monovalent vaccination was 25 percent effective in preventing hospitalization or death, while bivalent vaccination was 62 percent effective.
Although the booster shot worked for everyone, experts say the elderly will benefit more because they are more likely to be hospitalized for Covid-19. “Even if this efficacy is the same, it’s even more important to boost older people because their absolute risk is higher,” said Danyu Lin, a professor of biostatistics at the University of North Carolina at Chapel Hill who led the study.
A CDC study examining whether a bivalent enhancer protects against infection in people aged 18 to 49 it was also encouraging. Compared with people who received between two and four doses of the original vaccine, people who received the bivalent booster were approximately 50 percent less likely to have symptomatic infection with BA.5 or XBB/XBB.1.5.
However, as with the original vaccine, the bivalent booster slightly increases the risk of myocarditisinflammation of the heart muscle, in persons aged 18 to 35 years. As a result, some experts are hesitant to recommend multiple booster doses to this group.
“If you’re young, let’s say 35, 40 years old, otherwise healthy, you’ve already been vaccinated and boosted, and you’ve probably had an infection or two in the past, I think that person is pretty well protected for a while,” Dr. David said. Ho, a professor of medicine at Columbia University who led one of the antibody studies.“Until more data is available, I would not force such a person to get an annual vaccination.”
What will boosters look like in the coming months and years?
The FDA suggested that for most Americans, the booster could to give annually in the fall, like the flu vaccine, and high-risk individuals could still receive multiple doses annually. It is not clear when or if they will officially recommend this approach.
dr. Lin has unpublished research comparing results according to the number of booster doses people receive per year. His data show that people who receive an average of less than one booster shot per year have higher rates of hospitalization and death than people who receive one or more doses. There is much less difference between one and more than one booster dose per year. He said this suggests that annual vaccination is sufficient for most people; however, for older adults, even a small benefit resulting from more vaccinations per year is likely to be worthwhile.