One dose of Pfizer or Moderna vaccines was 80% effective

March 30, 2021:- A single dose of Pfizer’s or Moderna’s Covid-19 vaccine was 80% effective in preventing the risk of coronavirus disease, according to a new Centers for Disease Control and Prevention study of vaccinated health-care workers.

According to the CDC, partial immunization effectiveness was seen two weeks after the first dose, which looked at around 4,000 health-care personnel, first responders, and front-line workers between December 14 and March 13. The health-care personnel and other workers in the study, which was published on Monday, had no previous laboratory documentation of Covid-19 disease.

“These findings indicate that authorized mRNA COVID-19 vaccines are effective to prevent from SARS-CoV-2 infection, despite the symptoms shown, among working-age adults in real-world conditions,” the U.S. agency wrote in the study.

The CDC findings were published before the agency’s director, Dr. Rochelle Walensky, told reporters that the U.S. is facing “impending doom” as daily Covid-19 cases start to rebound once again, which threaten to send more people to the hospital even as vaccinations are accelerating nationwide.

Dr. Paul Offit, a voting member of the FDA’s Vaccines and Related Biological Products Advisory Committee, reviewed both the vaccines for emergency use authorization, said the CDC study overall is “good news.”

However, he is worried that people will now think one dose of the vaccines is “good enough” and won’t return for a second dose. Studies have shown immunity appears to be more “durable” after the double amount, which means protection may last longer,  he added.

According to the CDC, among the 3,950 participants in the study, 2,479, or 62.8%, received both the doses, and 477, or 12.1%, received only one recommended dose.

The infection rate among vaccinated participants was 0.04, compared with 1.38 for those who were not vaccinated.

The study took place across eight U.S. locations, including Phoenix, Tucson, and other Arizona areas; Miami, Florida; Duluth, Minnesota; Portland, Oregon; Temple, Texas; and Salt Lake City, Utah. According to the CDC, most of the participants were female, white, and had no chronic medical conditions.