The Food and Drug Administration authorized J&J boosters in October as part of a broader expansion of the country’s booster campaign heading into the fall and winter. All J&J recipients who are at least two months past their shot may get a booster, a recognition of that vaccine’s lower efficacy compared to the Pfizer-BioNTech and Moderna Covid shots. The one-dose J&J vaccine is authorized for people 18 and older.
J&J’s shot has had limited uptake in the U.S. since the federal government paused its use in April over concerns about blood clotting post-inoculation. The company’s U.S. production was also interrupted for months by problems at a contractor’s plant.
J&J said prior to the emergence of Omicron, in October, that giving a second dose two months after the first increased protection against symptomatic moderate to severe Covid-19 to 94 percent, with 100 percent protection against severe illness.
Vaccine manufacturers and the Biden administration continue to evaluate whether booster shots should be considered part of the original Covid-19 vaccine regimen as the Omicron strain rapidly spreads across the country.