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.
“That’s too low, especially in this world where we have access to other things,” said Natalie E. Dean, a biostatistician at Emory University’s Rollins School of Public Health. “One priority is making sure that people who only received one dose [of Johnson & Johnson vaccine] are aware that they should go and get, preferably, a messenger RNA vaccine.”
The data also suggest a second boost with a messenger RNA vaccine may need to be considered, even for individuals who have received two doses of Johnson & Johnson, said Boghuma Titanji, an infectious-diseases expert at Emory University. “This is not yet a formal recommendation,” Titanji said, “but is something individuals who fall in this category should discuss with their health-care provider.”
The takeaway: “If you can get the messenger RNA vaccine series, and especially get one as a booster, this [study] confirms that is the way to go,” said Jeanne Marrazzo, director of the Division of Infectious Diseases at the University of Alabama at Birmingham.
Experts said the latest CDC study underscores what some experts say is a critical need for clearer recommendations on boosters.
“Right now, there aren’t recommendations for people who got two doses of J & J to get a third messenger RNA shot,” said William Moss, executive director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health. (Those who are moderately to severely immunocompromised are already recommended to get a third dose.) “The messenger RNA vaccines seem to be providing more protection … What I’d like to see is a very simple recommendation: that everyone get three doses, and they should be messenger RNA vaccines.”
Several studies have shown the Pfizer and Moderna vaccines remain highly effective at preventing the worst outcomes from infections even as protection against less severe illness waned over time.
Although the Johnson & Johnson vaccine provides a lower level of initial protection than the messenger RNA vaccines, the company has pointed to evidence that its vaccine’s protection may not erode as quickly.
A study funded by the division of Johnson & Johnson that developed the…
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