TORONTO: Scientists at the University Health Network have conducted a first-in-the-world randomized placebo-controlled trial of third dose Covid-19 booster vaccine for transplant patients that shows substantially improved protection. The study, published in the New England Journal of Medicine, has shown that a third dose of Covid vaccine is the best way to increase protection in individuals.
The team enrolled 120 transplant patients between May 25 and June 3. None of them had Covid previously and all of them had received two doses of the Moderna vaccine. Half of the participants received a third shot of the vaccine (at the 2-month mark after their second dose) and the other half received placebos.
The primary outcome was based on antibody level greater than 100 U/ml against the spike protein of the virus. In the placebo group. Ater three doses (where the third dose was placebo), the response rate was only 18 percent whereas in the Moderna three-dose group, the response rate was 55 percent."This is an important win for our patients because the results are quite conclusive," said Dr Atul Humar, Medical Director of the Ajmera Transplant Centre, UHN. He added that"The third dose was safe and well-tolerated and should lead to a change in practice of giving third doses to this vulnerable population." In addition, 60 percent of the patients in the Moderna group also developed neutralizing antibodies versus 25 percent in the placebo group.