The Centers for Disease Control and Prevention (CDC) released the data as the Food and Drug Administration (FDA) considers booster doses of the Pfizer vaccines for those who are past 6 months of vaccination.

In a study involving a case-control analysis of 3,689 adults who were hospitalized at 21 US hospitals at some point from Mar 11 through Aug 15, the vaccine effectiveness (VE) against COVID-19 hospitalizations was 93% for Moderna, 88% for Pfizer/BioNTech, and 71% for the single-dose Johnson & Johnson (J&J) vaccine.

"Although these real-world data suggest some variation in levels of protection by vaccine, all FDA-approved or authorized COVID-19 vaccines provide substantial protection against COVID-19 hospitalization," the authors wrote.

One hundred healthy study participants also provided serum samples for a postvaccination antibody analysis, with blood collected 2 to 6 weeks after receipt of the second Moderna and Pfizer vaccine dose or the single J&J vaccine dose.

Again, recipients of the Moderna vaccine, followed by Pfizer then J&J had higher anti-spike Immunoglobulin G levels, a sign of a stronger antibody response.