COVID-19 vaccines “ebb and flow” over the next few weeks, officials in London, Ont., are reassuring residents concerned about mixing and matching the two mRNA vaccines.The Middlesex-London Health Unit announced Sunday that three of its mass vaccination clinics would only be offering adults Moderna’s vaccine this week, due to a delayed delivery of Pfizer’s vaccine.
3 London-Middlesex COVID-19 vaccination clinics to switch from Pfizer to Moderna Monday During the MLHU’s COVID-19 update on Monday, medical officer of health Dr.