Ontario’s Dr. Moore to announce expansion of fourth vaccine boosters on Wednesday

Ontario’s chief medical officer of health is expected to announce details on Wednesday about COVID-19 vaccine boosters, set to be made available to adults between the ages of 18 and 59.

A spokesperson says Dr. Kieran Moore will speak at 11 a.m. about “expanding access to fourth doses of COVID-19 vaccines.” Dr. Moore will also touch on the province’s rapid antigen test (RAT) program.

The province’s top doctor confirmed in an interview with CityNews last week that the latest round of booster shots would be made available in July.

In that interview, Dr. Moore said these boosters would not preclude Ontarians from another follow-up shot three months later, as that vaccine would be re-formulated to add additional layers of protection.

“We’re going to make it, so those 18 to 59 are eligible for a second booster,” Dr. Moore told CityNews on July 7.

Currently, third doses are available to people 12 and older, and fourth doses are available for people 60 and older or First Nation, Inuit and Metis adults as well as their adult household members.

Immunocompromised people — such as transplant recipients — aged 60 and older and long-term care residents can get the fifth dose.

Dr. Moore said the upcoming second booster shots will be of the original strain and include only Pfizer or Moderna.

The top doctor says the government is considering a “base strain” vaccine in the fall, and an additional strain of an Omicron variant — either the BA.1 or BA.5 subvariant — which has become dominant in Ontario.

Ontario’s Science Advisory Table published new findings last week, saying the province had “likely entered a wave” of COVID-19, driven by the Omicron BA.5 subvariant.

New Omicron mutation spreading globally

Dr. Moore’s scheduled press conference comes as a new mutation of the Omicron variant continues to spread rapidly in countries like India.

U.S. scientists say the variant — classified as BA.2.75 — may be able to spread rapidly and get around immunity from vaccines and previous infection.

It’s unclear whether it could cause more severe disease than other Omicron variants, including the globally prominent BA.5. It’s been detected in about 10 countries, including Australia, Germany, the United Kingdom and Canada.

Two cases were recently identified on the West Coast of the U.S., and Helix identified a third U.S. case last week.

Ontario is now at least three weeks into a seventh COVID-19 wave, Dr. Moore said, noting a difference between past waves in the winter when Omicron was spreading at a dangerous and rapid pace.

The top doctor says the province can endure this smaller wave, noting that Ontario has another week to 10 days to see the maximal effect.