The Moderna vaccine offers more protection against Covid-19 than the Pfizer-BioNTech and J&J vaccines, according to a new CDC study reported in the latest issue of The Morbidity and Mortality Weekly Report (MMWR).¹

The multicenter study involved 3689 adults aged ≥18 years who were hospitalized this year with COVID-19–like illness and a positive SARS-CoV-2 RT-PCR or antigen test result from March 11 to August 15. A patient was considered fully vaccinated if the final vaccine dose (second dose for Moderna and Pfizer-BioNTech and the single Janssen dose) was received ≥14 days before the onset of illness.

On analysis, the Moderna vaccine was found to be more effective against COVID-19 hospitalization compared to the Pfizer-BioNTech vaccine; 93% vs 88%, respectively. The vaccine effectiveness against COVID-19 hospitalization was higher with Moderna as well as Pfizer vaccines vis a vis J&J vaccine, which had a vaccine effectiveness of 71%.

Upto120 days after the second dose, the vaccine effectiveness for Moderna vaccine was 93%. The vaccine was still effective after 120 days (median 141 days). While the Pfizer vaccine had comparable effectiveness (91%) up to 120 days after the second dose, protection significantly dropped to 77% after 120 days (median = 143 days).

Antibodies (IgG) to the spike protein, receptor binding domain (RBD) and the nucleocapsid were also evaluated separately in 100 healthy subjects 2 to 6 weeks after they had been fully vaccinated with the Moderna, Pfizer-BioNTech or J&J vaccine. Immunocompromised patients were not included in this analysis. The anti-RBD level after the Moderna vaccine was 4333 (median) vs 3217 with Pfizer vaccine vs 57 with the J&J vaccine. Similarly, the anti-spike IgG levels in participants vaccinated with the Moderna vaccine were 3236 vs 2983 after Pfizer vs 59 with J&J vaccine.

This study has shown that the two dose mRNA vaccines had higher efficacy compared to the single dose J&J vaccine. And, of the two mRNA vaccines, the Moderna was more effective than the Pfizer vaccine in protecting against hospitalizations due to Covid-19. Also, the antibody levels obtained with the two mRNA vaccines were much higher than the levels achieved after the J&J vaccine. The antibody levels again were found to be higher for Moderna vaccine compared to the Pfizer vaccine.

According to the study authors, the differences in the vaccine effectiveness among the two mRNA vaccines could be attributed to the differences in timing between the two doses and the higher amount of mRNA in the Moderna vaccine. The two doses of the Pfizer vaccine are administered 3 weeks apart, while for the Moderna vaccine, this gap is 4 weeks.

While this study has demonstrated a difference in the effectiveness of the three vaccines studied, it does not take away the fact that all approved Covid-19 vaccines are safe and effective. And, everyone must take a Covid-19 vaccine at the earliest. The reported adverse effects with the vaccine are rare. The benefits of the vaccines certainly outweigh the associated risks.

References

1. Self WH, et al. Comparative effectiveness of Moderna, Pfizer-BioNTech, and Janssen (Johnson & Johnson) vaccines in preventing COVID-19 hospitalizations among adults without immunocompromising conditions - United States, March-August 2021. MMWR Morb Mortal Wkly Rep. 2021 Sep 24;70(38):1337-43.