US CDC: COVID-19 Hospitalization Prevention Effectiveness Ranks Moderna-Pfizer-Janssen

[Image source=Reuters Yonhap News]

[Asia Economy Reporter Seoyoung Kwon] Among the three types of COVID-19 vaccines approved in the United States, a study by the U.S. Centers for Disease Control and Prevention (CDC) found that Moderna's vaccine is the most effective in preventing hospitalization.

On the 17th (local time), the CDC's "Morbidity and Mortality Weekly Report" (MMWR) announced that, based on a survey of immunocompetent U.S. adults, the effectiveness of vaccines in preventing COVID-19-related hospitalization was 93% for the Moderna vaccine, 88% for the Pfizer vaccine, and 71% for the Janssen vaccine. This study was conducted under the leadership of the CDC from March 11 to August 15 at 21 hospitals in 18 U.S. states, involving 3,689 adults hospitalized due to COVID-19.

The CDC stated, "This real-world data shows that there are some differences in the level of protection provided by each vaccine," but also emphasized, "All vaccines approved by the Food and Drug Administration (FDA) are significantly effective in preventing hospitalization due to COVID-19." Furthermore, the CDC explained, "According to this study, the two-dose Moderna and Pfizer vaccines provide stronger protection compared to the single-dose Janssen vaccine," while also noting, "The Janssen vaccine still reduced the risk of COVID-19 hospitalization by 71%."

Continuing, the CDC pointed out that the difference between the Moderna and Pfizer vaccines, which both use the messenger RNA (mRNA) method, became apparent due to a decline in immune effectiveness starting about four months after completing the Pfizer vaccination. They confirmed that the Pfizer vaccine's effectiveness was 91% during the period from 14 to 120 days after the second dose, but dropped significantly to 77% after 120 days.

The research team stated, "The difference in effectiveness between the Moderna and Pfizer vaccines may have been influenced not only by the higher mRNA content in the Moderna vaccine but also by differences in dosing intervals and the characteristics of the vaccinated populations." However, they added a limitation of the study, saying, "This research did not examine vaccine effectiveness in children, immunocompromised adults, or for COVID-19 infections that were not severe enough to require hospitalization."