Pfizer-BioNTech and Moderna Vaccines Highly Effective in the Real World: CDC

A new report by the Centers for Disease Control and Prevention released Friday found that both the Pfizer-BioNTech and Moderna mRNA vaccines are 94% effective in preventing symptomatic COVID-19. This real-world evidence that the vaccine works as well as clinical trials result promised comes from a study of more than 1,800 healthcare workers across the U.S.

This is important news, as studies have shown healthcare workers, particularly nurses, are at increased risk and have a higher prevalence of infection from COVID-19 than non-healthcare workers.

According to The New York Times, the ongoing research by the CDC involves 1,843 healthcare workers in 25 states who are regularly tested for COVID-19 infections. In that cohort, 623 workers tested positive for the virus between January and mid-March. The fully vaccinated workers were 94% less apt to develop troublesome symptoms than their fellow personnel who did not get COVID-19 vaccines. These real-world figures match the efficacy noted in the clinical trials of the vaccines, says the Times.

“This report provided the most compelling information to date that COVID-19 vaccines were performing as expected in the real world,” CDC director Dr. Rochelle Walensky said in a statement on Friday. She added that this new information bolstered the growing body of evidence that the vaccines work, and helped the CDC make its recent decision on relaxing mask mandates indoors.

“This study, added to the many studies that preceded it, was pivotal to CDC changing its recommendations for those who are fully vaccinated against COVID-19,” said Walensky.

Surprisingly, researchers found that even a single dose of vaccine offered 82% protection in preventing illness. That figure is higher than formerly reported. Previous research found that getting only one shot of the Pfizer drug provided 52% defense against the spread of the virus and the first shot of the Moderna vaccine imparted 80% protection. But there are no clinical studies to show how long partial protection lasts.

Experts say that because the healthcare workers surveyed had a median age of 37, and fewer than 2% were over the age of 65, their youthful profile may have increased the percentage of immunity after only one dose of the vaccine.

Medical professionals and immunologists still recommend getting both doses of the mRNA vaccines to ensure immunity against COVID-19 and its variants. According to Good Housekeeping, Dr. Nicholas Kman, an emergency physician at Ohio State University’s Wexner Medical Center, says getting both shots ensures as much immunity as possible against COVID-19. Kman says that while both vaccines do provide some protection against a person becoming infected by the virus after the first dose, the second dose increases the number of antibodies in bloodstream tenfold, offering 95% efficacy.