The waning effectiveness of vaccines to stop the spread of the highly infectious Omicron variant of COVID-19 could mean it’s time for federal policy makers to consider lifting vaccine mandates, some experts suggest.
“It’s hard to really justify our mandates anymore,” said Dr Zain Chagla, an infectious diseases physician at St. Joseph’s Healthcare Hamilton and an associate professor at McMaster University.
Toronto’s Pearson International Airport has recently been a scene of snarling air passenger traffic, causing long lineups and major delays.
While government officials have blamed staffing shortages for problems, some industry groups and politicians are laying the blame on COVID-related border restrictions including vaccine mandates that require travellers to prove their vaccine status using an app before entering Canada.
Prevent severe illness and death
Scientists stress that the vaccines do hold up against what matters — severe illness, hospitalization and death.
And Chagla said that when the Alpha and Delta variants of COVID-19 swept through, data showed that vaccination had a “profound effect” on stopping a significant amount of infections, and that people’s ability to transmit was reduced.
But the vaccines’ abilities to prevent transmission of the virus changed with the Omicron variant, he says.
Last month, in a editorial for The Globe and Mail, under the headline: “The logic behind vaccine mandates for travellers no longer holds,” Chagla wrote that with the Omicron variant, vaccine efficacy “wanes significantly” to help prevent transmission. He pointed to data from the UK Health Security Agency that he said showed the effectiveness of two or three doses of vaccine against spreading the Omicron-variant infection over time approaches zero.
“We live in a world now where a lot of people have either been vaccinated or got COVID, that maybe one to two per cent of people isn’t in that category,” he told CBC News. “Are we really working hard to make sure that they’re not able to access a flight?” he said.
“They’re not necessarily at an increased risk of transmission as compared to the fully vaccinated person against the next variant.”
WATCH | Frustrations mount over delays at Toronto’s Pearson International Airport:
Proof-of-vaccine certificates to enter public places have been largely removed in all provinces Canada. The remaining proof-of-vaccination policy requirement applies to federally regulated employees and for travel especially by air overseas and to enter Canada.
However, the Public Health Agency of Canada recently announced that COVID-19 restrictions at the border will remain in place for at least another month. Those restrictions include vaccine mandates, which require travellers to use the ArriveCan mobile app to download proof of their vaccination before entering Canada.
Those who do not are subject to testing and quarantine.
Conservative motion shot down
The Canadian Airports Council and the Canadian Travel & Tourism Roundtable are among some industry organizations calling for vaccine mandates to be dropped.
WestJet Airlines has also called for the removal of mandates. Meanwhile, a federal Conservative motion calling for the removal of pandemic-related restrictions, including vaccine mandates, was shot down last month.
But Dr. Nazeem Muhajarine, professor of community health and epidemiology at the University of Saskatchewan in Saskatoon, said that some research does indicate that vaccine booster doses do protect people from transmission of the virus.
That’s why he believes “this last remaining vaccine policy should remain a little longer because the threat of COVID-19 and the harm it causes in terms of long COVID, deaths and hospitalization particularly in vulnerable people, elderly and in some cases in children hasn’t entirely disappeared.”
Yet, Dr. Amesh Adalja, an infectious disease physician and senior scholar at the Johns Hopkins Center for Health Security in Baltimore, questioned the value those mandates now serve in light of the Omicron variant and population immunity.
“I think that increasingly it’s become less valuable than it was in the earlier eras in the pandemic, because the vaccine in the face of Omicron isn’t very great at protecting against infection, he said.
‘Much less value’ for travel
Because the vaccines hold up against severe illness, hospitalization and death, Adalja said there is still great value for employers to insist their workforce be vaccinated from a work-safety standpoint.
As for vaccine mandates for travel, “I think it has much less value,” he said. “I don’t think the ArriveCan [app] serves the same value that it once did.”
Appearing before a House of Commons health committee earlier this week, Canada’s Chief Public Health Officer Dr. Theresa Tam said the mandates were first implemented when there was a strong resurgence of the Delta variant and two doses of vaccines were very effective.
But Omicron was the “game changer,” she said.
“Given the reduced vaccine effectiveness, even with three doses against the Omicron variant, vaccines cannot prevent all transmissions alone,” she said. “So a layered approach has to be considered, including layering mask wearing, for instance. But these are the things that the relevant ministers need to consider.”