One Dose of Pfizer Vaccine Reduces Transmission, Study Finds

Three new British studies show the Pfzier-BioNTech COVID-19 vaccine, which is considered a two-dose vaccine, reduced transmission of the virus after one dose, particularly in people who had previously tested positive.

One study conducted by Britain’s University of Cambridge Hospital and published Friday suggests a single dose of the Pfizer BioNTech vaccine can reduce by four times the number of asymptomatic COVID-19 infections. According to researchers, that indicates the vaccine could significantly reduce the risk of transmission of the virus from people who are asymptomatic, as well as protecting others from getting ill.

Lead researcher on the study, Cambridge University Hospital Infectious Disease Specialist Dr. Mike Weekes, said, “This is great news – the Pfizer vaccine not only provides protection against becoming ill from SARS-CoV-2 but also helps prevent infection, reducing the potential for the virus to be passed on to others.”

The study has not been peer reviewed but researchers say they published ahead of that review because of the urgent need to share information relating to the pandemic.

Two other studies, published late Thursday in the British medical journal The Lancet, indicate a single dose of the Pfizer-BioNTech vaccine is enough to protect people who have had COVID-19 from getting it again.

The studies were conducted by the University College London and Public Health England, and the Imperial College of London.

In other news regarding the Pfizer-BioNTech vaccine, the U.S. Food and Drug administration late Thursday said the vaccine can be kept at conventional freezer temperatures for up to two weeks, rather than the ultra-cold temperatures originally required for the vaccine.

The makers of the vaccine had applied for the approval last week, after their studies concluded the vaccine was still safe and effective when stored at conventional freezer temperatures. The ruling will make the vaccine far easier and less expensive to distribute and store.