between Moderna’s vaccine and Pfizer/ BioNtech’s vaccine was caused by a decrease that began about four months after patients had complete vaccination with Pfizer’s vaccine. According to the team, the efficacy rate for both the vaccines were different. They said, “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 (three weeks for Pfizer-BioNTech versus four weeks for Moderna), or possible differences between groups that received each vaccine that were not accounted for in the analysis”. They added, “Vaccine effectiveness for the Pfizer-BioNTech vaccine was 91% at 14 -120 days after receipt of the second vaccine dose but declined significantly to 77% at more than 120 days”.
Both Pfizer and Moderna vaccines transmit immunity via genetic material called messenger RNA, although their dosages and formulations are marginally different. The Janssen vaccine delivers genetic instructions into the body using an inactivated common cold virus known as adenovirus, a viral vector. The team also analysed the effectiveness of the Janssen vaccine. According to the team, “A single dose of the Janssen viral vector vaccine had comparatively lower anti-SARS-CoV-2 antibody response and vaccine effectiveness against COVID-19 hospitalizations”. The team further added, “Understanding differences in vaccine effectiveness by vaccine product can guide individual choices and policy recommendations regarding vaccine boosters. All FDA-approved or authorized COVID-19 vaccines provide substantial protection against COVID-19 hospitalization.”
The CDC collaborated with experts from throughout the country to investigate 3,689 patients at 21 hospitals across 18 states. Additionally, they examined 100 healthy volunteers’ blood antibodies following immunization with one of the three vaccines.
The team concluded their comparative analysis saying, “These real-world data suggest that the two-dose Moderna and Pfizer-BioNTech mRNA vaccine regimens provide more protection than does the one-dose Janssen viral vector vaccine regimen. Although the Janssen vaccine had lower observed vaccine effectiveness, one dose of Janssen vaccine still reduced risk for COVID-19-associated hospitalization by 71%”. According to the team, this study also had certain limitations. They said, “This analysis did not consider children, immunocompromised adults, or vaccine effectiveness against COVID-19 that did not result in hospitalization”. Plus, the participants were only monitored for 29 weeks.
