Coronavirus: Canada-wide study to investigate mix-and-matching vaccine doses

A new Canada-wide study will look at the effect of using different COVID-19 vaccine doses in Canadian adults to determine if mixing and matching vaccines yields a strong immune response and how long the response lasts. The study, announced Thursday, will investigate the use of different vaccines for first and second doses in 1,300 adult participants. The study will be conducted in conjunction with the COVID-19 Immunity Task Force, Vaccine Surveillance Reference Group, Canadian Immunization Research Network and Dalhousie University. 'As questions of vaccine interchangeability arise and alternative dosing intervals are being used in public health programs, our objective is to determine: what are the effects of different dosing intervals of the vaccines on immunity and safety?' said Dr. Joanne Langley, co-principal investigator of the study and professor at Dalhousie University, said in a press release.