People who received a Johnson & Johnson Covid vaccine might be better off with a booster shot from Moderna or Pfizer-BioNTech, a new study found.
Those who received the single-dose vaccine by Johnson & Johnson followed by a Moderna booster shot saw their antibody levels rise 76-fold within 15 days, while those who received another dose of the Johnson & Johnson vaccine saw only a fourfold rise in the same period. And a Pfizer booster shot raised antibody levels 35-fold in Johnson & Johnson recipients.
Separately, the authorities in China have begun rolling out third shots of vaccines for high-risk groups as the country races to meet its goal of fully vaccinating 80 percent of its population by the end of the year. The W.H.O. has recommended an additional dose for people over 60 who were inoculated with vaccines made by the Chinese companies Sinopharm and Sinovac.
Here are the latest updates and maps of the pandemic.