Manitoba 'not finished yet' with COVID-19 vaccination efforts as province rolls back pandemic restrictions

Manitoba may be moving toward lifting its COVID-19 restrictions as more than 80 per cent of its eligible population has gotten fully vaccinated — but that doesn't mean the province is planning to roll back its immunization campaign anytime soon.

Dr. Joss Reimer, the medical lead of the province's vaccine implementation task force, said that's in part because of recent studies that suggest an Omicron infection doesn't provide significant protection against other strains among people who haven't been immunized.

As of Wednesday, 81.3 per cent of eligible Manitobans had received two doses of COVID-19 vaccine, the province's website says.

But that still leaves almost 19 per cent of people unvaccinated — plus the more than 57 per cent of those eligible who haven't yet gotten their third dose.

"So even though the majority of Manitobans are well protected, we are not finished yet," Reimer said at the province's weekly virtual news conference with public health officials on Wednesday.

"The work continues, because we still need to reach those Manitobans who have not made the decision to be vaccinated."

Reimer outlined three recent studies that suggest unvaccinated people who get infected with the Omicron coronavirus variant won't be protected against infection from any future variants.

All three lab-based studies are preprints published in medRxiv, an online portal for research that is so far unpublished and not yet peer-reviewed. 

One study, which looked in the first half at mice and in the second half at humans, examined how well the blood of those who had been infected with COVID-19 could neutralize different strains of the virus that causes it, Reimer said.

That study found that unvaccinated people previously infected with Omicron may not be able to produce an immune response that protects them against other variants. But in vaccinated people, the addition of an Omicron infection may be effective at producing antibodies, she said.

Another study from Austria had almost the exact same results when looking at a group of people who were infected with Omicron, she said.

Some were vaccinated, some had been previously infected with another strain of the virus and some had neither form of protection.

Researchers in that study concluded that vaccinated people and those with a previous COVID-19 infection had high levels of antibodies produced against all of the variants.

But unvaccinated people whose first coronavirus infection was with the Omicron variant only had a low number of antibodies against Omicron and tested negative for antibodies against all other variants, Reimer said.