The first data in people on the new COVID-19 boosters shows them to be just as safe as previous shots and to provide a strong immune response.
The new boosters target both the original version of the virus that causes COVID-19 as well the BA.4 and BA.5 variants that have dominated since early summer. The boosters were authorized based on animal data so they could be available this fall, ahead of an expected surge in cases later in the year.
A similar process is followed with the flu vaccine, which is modified every year to address anticipated strains. Testing is only in animals.
Pfizer and its partner BioNTech announced Thursday that they now have data in adults one week after a 30-microgram booster that targets both variants. It is called a bivalent vaccine because it addresses two variants.
Two groups of 40 adults each, one age 18-55 and the other over 55, both tolerated the new shot as well as earlier ones and had no unexpected side effects.
The bivalent booster significantly increased neutralizing antibodies against the BA.4 and BA.5 variants, according to company press releases, though older people developed less of an immune response to the new variants than younger people.
Moderna, which also provides a bivalent booster, has not yet released any data on people.
It’s still too soon to know whether a bivalent booster will be more protective against infection or severe disease than the original, monovalent booster, or whether someone’s age will make a difference in their vulnerability. Older people have been more likely to suffer severe COVID-19 infections than younger ones.
Among most Pfizer-BioNTech trial participants, about 6 months passed between their original vaccines and the first booster, which took place about 11 months before this second booster.
The companies expect to release more results when trial participants reach the one-month mark.
This week, the federal government authorized the bivalent boosters for children 5 to 11. The shots had previously been authorized in adolescents. There is no data yet on people for either group.
The booster shots are “authorized” rather than “approved” because, in the midst of a pandemic, regulators didn’t want to wait for six months of human data, which is the standard for approval. The initial shots have been fully approved for adults and teenagers with requests pending for younger children and boosters.
Contact Karen Weintraub at kweintraub@usatoday.com.
Health and patient safety coverage at USA TODAY is made possible in part by a grant from the Masimo Foundation for Ethics, Innovation and Competition in Healthcare. The Masimo Foundation does not provide editorial input.
