A new study seeking to shed light on real-world COVID-19 vaccine effectiveness shows a widening gap between Moderna’s and Pfizer’s vaccines four months after the second shot.
Among the 3,600-plus U.S. adults without immunocompromising conditions who were enrolled in the study, vaccine effectiveness against COVID-19 hospitalization within the first four months of being fully inoculated was higher for the Moderna vaccine (93 percent) than the Pfizer-BioNTech vaccine (88 percent) and the J&J vaccine (71 percent), according to the Centers for Disease Control and Prevention (CDC).
While the Moderna vaccine’s effectiveness dropped slightly to 92 percent after 120 days of full vaccination (with a median of 141 days), Pfizer’s declined significantly to 77 percent (with a median of 143 days), the researchers found.
Because only a limited number of patients received the J&J shot more than 120 days before the onset of illness, its effectiveness was not stratified by time in the study, which was conducted between March 11 and Aug. 15 of this year. Also, confidence intervals for estimating the J&J vaccine’s effectiveness were wide because of the relatively small number of patients inoculated with the product, according to the researchers.
“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 CDC noted.
The study did not evaluate vaccine efficacy by variant, including Delta, nor did it gauge effectiveness against COVID-19 that did not result in hospitalization. The analysis also did not consider effectiveness in children and immunocompromised adults.
COVID-19 is the disease caused by the CCP (Chinese Communist Party) virus, also known as SARS-CoV-2 or the novel coronavirus.
The study was published on Sept. 17, the same day that the U.S. Food and Drug Administration’s vaccine advisory panel voted 16–3 to recommend booster shots of Pfizer’s COVID-19 vaccine for individuals aged 65 and older and those at high risk of occupational exposure. At the same time, the panel voted 18–0 to recommend against booster shots for those aged 16 to 65.
By Tom Ozimek
