On Sept. 17, the Center for Disease Control and Prevention (CDC) published a report which compared the efficacy of the three vaccines currently available in the United States to protect against COVID-19. An important note of the report is that it measures the effectiveness of vaccination fighting against hospitalization from COVID-19, specifically “among adults without immunocompromised conditions.” The assessment was done between the CDC and unspecified collaborators using a case-control analysis among 3,689 adults aged 18 or older, those of whom were hospitalized at 21 different hospitals spanning 18 states.
The analysis was done throughout the period of Mar. 11 to Aug. 15, 2021. Further analysis was conducted using serum antibody levels and anti-receptor binding domain to SARS-CoV-2 across a sample size of “100 healthy volunteers enrolled at three hospitals 2 to 6 weeks after full vaccination with the Moderna, Pfizer-BioNTech or Janssen COVID-19 vaccine.”
The results of the studies found that Moderna’s vaccine was the most effective at protecting from hospitalization due to COVID-19, with a finding of 93% of individuals who tested positive for the virus not requiring medical care, which included both those that were asymptomatic and suffered from mild symptoms. Pfizer’s vaccine landed closely in second place, with an effectiveness rate of 88%. Both of the two-dose shots were significantly higher than Johnson & Johnson’s vaccine, which ended up with an effectiveness rate of 71%.
The CDC review continued to find that for the two-dose vaccinations, protection declined after about four months of being fully vaccinated. Despite the findings of various levels of defense offered by the vaccines, the report concluded by saying that “all FDA-approved or authorized COVID-19 vaccines provide substantial protection against COVID-19 hospitalization.” In regard to the topic of booster shots to provide individuals more defense against the virus, on Sept. 22, the Food and Drug Administration (FDA) “amended the emergency use authorization (EUA) for the Pfizer-BioNTech COVID-19 vaccine to allow for use of a single booster dose.” These booster doses are meant to be administered following six months of being fully vaccinated. The EUA also only applies to Pfizer’s vaccine. Currently, these shots are only being recommended for those aged 65 and older, those between 18 and 64 with a high-risk of severe COVID-19 and individuals between 18 and 64 who might be frequently exposed to the virus due to occupational or institutional needs.