Two new studies show the high effectiveness of COVID-19 vaccines and boosters against three variants of concern (Alpha, Delta, and Omicron), CDC reports, reiterating the importance of staying up to date with vaccinations as the best protection against severe illness and the safest way to reduce the emergence of new variants.
According to a study that CDC released last week, adults who received two or three doses of the Pfizer-BioNTech or Moderna vaccine and were hospitalized with COVID-19 during the Delta and Omicron waves had 90–95% less risk of dying or needing a ventilator (IMV) compared with unvaccinated adults.
The data showed that “during the Omicron period, the vaccine efficacy against IMV or in-hospital death was 79% for recipients of 2 doses and 94% for recipients of 3 doses.”
The second study, published in the British Medical Journal, found that mRNA vaccines gave a high level of protection against hospitalization for all variants, and that vaccinated hospital patients had much lower disease severity than unvaccinated patients.
Data has shown that the protection wasn’t as high for Omicron among adults who received only a primary series, but it increased with boosters.
The British Medical Journal study also showed that, although mRNA vaccines are highly effective in preventing hospitalizations related to the Alpha, Delta and Omicron variants, boosters “were required to achieve protection against Omicron similar to the protection that two doses provided against the Delta and Alpha variants”.
Half of Americans haven’t received a booster
While these and other studies have shown the efficacy of the boosters, about half the country’s population has not received them, the CDC said. Some 557.6 million vaccine doses had been administered in the United States between the start of the COVID-19 vaccination programme on December 14, 2020 and March 16, the CDC reported.
Around 65.3% of the total US population (about 216.8 million people) have been fully vaccinated and 96.2 million have already received a booster dose, but “49.9% of the total booster-eligible population has not yet received a booster dose,” CDC said.
CDC’s COVID Data Tracker Vaccination Demographic Trends tab shows that “of all race/ethnicity groups, the Asian non-Hispanic population has the highest proportion that is fully vaccinated (60.2%), and the Black non-Hispanic population has the lowest proportion that is fully vaccinated (41.1%).”
The highest proportion of additional/booster doses (66.9%) was recorded among the Asian non-Hispanic population while “the Hispanic/Latino population has the lowest proportion (40.1%).”