US researchers have started a clinical trial to test what happens when adults who have been fully vaccinated with one type of COVID-19 vaccine receive booster doses of a different COVID-19 vaccine. Each vaccine group will enroll about 25 people aged 18 to 55 years, and about 25 people aged 56 years and older. Twelve to 20 weeks following their initial vaccination regimen, participants will receive a single booster dose of the Moderna COVID-19 vaccine as part of the trial. People who have not received the COVID-19 vaccine are also eligible to enroll in the trial in a separate cohort. These volunteers will initially receive the two-dose Moderna COVID-19 vaccine regimen and will be assigned to receive a booster dose of a vaccine about 12 to 20 weeks later, according to the NIH.

Source: dna June 03, 2021 02:48 UTC