Moderna found to be most effective vaccine, CDC-led study finds

A head-to-head study of all three coronavirus vaccines authorized in the United States finds the Moderna vaccine is slightly more effective than Pfizer's in real-world use at keeping people out of the hospital, and Johnson & Johnson's Janssen vaccine comes in third, but still provides 71% protection.

 

Pfizer's vaccine provided 88% protection against hospitalization, and Moderna's was 93% effective.

 

The CDC led a nationwide study of vaccination involving more than 3,600 adults hospitalized for Covid-19 between March and August.

 

They found that the biggest difference between the vaccine made by Moderna and Pfizer/BioNTech was driven by a decline that started about four months after people were fully vaccinated with Pfizer's vaccine.

 

"Differences in vaccine effectiveness between the Moderna and Pfizer-BioNTech vaccine might be due to higher mRNA content in the Moderna vaccine, differences in timing between doses (3 weeks for Pfizer-BioNTech versus 4 weeks for Moderna), or possible differences between groups that received each vaccine that were not accounted for in the analysis," the team wrote.