Even combining a Johnson & Johnson vaccine with a booster of either Johnson & Johnson, or one of the two messenger RNA vaccines, wasn’t as strong as three shots of the messenger RNA vaccines in preventing emergency room visits or hospitalizations, according to the report.
Shortly after the study’s release, the CDC gave a green light for a second booster, either of the Pfizer-BioNTech or Moderna shots, for those who received Johnson & Johnson’s vaccine and booster at least four months ago. It did not formally recommend the second booster but said people may get it if they choose. More than 1.3 million people received the Johnson & Johnson vaccines and booster, according to CDC data.
The study’s results confirm what health officials and scientists have known for some time based on earlier research. But the report is important because vaccine effectiveness data on the mix-and-match booster strategies in the real world has been limited.
The data, from a 10-state study conducted by independent researchers, may provide clarity amid a confusing stew of data about the single-dose vaccine. It shows that three doses of a messenger RNA vaccine perform the best, while a Johnson & Johnson vaccine followed by a messenger RNA booster shot is next best. Two shots of Johnson & Johnson provide a lower level of protection, with a single shot just 31 percent effective against hospitalization. ...
