Nearly three in four cases of COVID-19 in Waterloo Region since the start of May have been in unvaccinated people and most of the rest are in the partially vaccinated population, the region's medical officer of health said Friday.

Speaking at the region's COVID-19 briefing on Friday, Dr. Hsiu-Li Wang said since May 1, 72.1 per cent of cases were in unvaccinated people, while 25.3 per cent were partially vaccinated and 2.6 per cent were fully vaccinated "breakthrough" cases.

Hospitalizations showed a similar pattern, with 72.1 per cent of patients unvaccinated, 25.2 per cent were partially vaccinated and 2.7 per cent were fully vaccinated.

Since May 1, five deaths were reported among people who were fully vaccinated. Dr. Wang said four of those deaths were associated with outbreaks at long-term care homes.