Health Canada says at least 1.3 million Canadians opted for a mixed-dose finish to their COVID-19 vaccination schedule in June.
The weekly vaccination coverage report published Monday shows about 6.5 million people got their second shot between May 31 and June 26, with one-in-five getting a different vaccine than their first.
A Canadian Press analysis of the data suggests at least half of the mixed-vaccine group were people who got the Oxford-AstraZeneca dose first before turning to either Pfizer-BioNTech or Moderna for their second.
It's estimated about one-fifth of those were people who got Pfizer first, but because of the way Health Canada reports the data, it's not entirely clear which vaccine they got for their second, or what combination of vaccines were given to the rest of the mixed-dose group.
Health Canada began reporting data on mixed vaccinations in early June, after the National Advisory Committee on Immunization recommended that people who got Oxford-AstraZeneca for their first dose could be safely offered an mRNA vaccine for their second.
NACI went further on June 17 when it said getting mRNA after AstraZeneca was the preferred option, citing the rare but serious risk of blood clots potentially linked to getting the AstraZeneca vaccine and evidence that mixing vaccines produces a stronger immune response.