The primary objective of this study is to test whether vaccinating LTCF residents ≥65 years with a fourth dose of Pfizer-BioNtech mRNA- COVID-19 vaccine as compared to control (PCV13) leads to an increase in detectable neutralizing antibodies. Participants will be randomized to receive either the Pfizer COVID-19 vaccine or the Pnemoccocal Prevnar-13 vaccine at baseline after bloodwork is drawn. Another blood sample will be taken 28 days later. After completion of the study, participants in the control group (pneumococcal Prevnar-13 vaccine) will be given a fourth dose of mRNA COVID-19 vaccine and will have their blood drawn 28 days post-vaccination.
This study is a multi-centre, blinded, randomized controlled trial. LTCF residents ≥ 65 years who have received three doses of mRNA vaccine will be randomized to vaccination with a fourth dose of Pfizer-BioNtech mRNA- COVID-19 vaccine or to vaccination with a control (Prevnar-13 vaccine).