This article was written based on interviews conducted for the Capital Daily podcast. Listen and subscribe here.

New modelling data from Simon Fraser University shows that BC must vaccinate adults 10-19 to reach herd immunity, the point at which enough people in the general population are immune to COVID-19 that the virus can no longer spread widely. 

The Capital Daily podcast spoke with the co-author of the SFU study, Caroline Colijn, about herd immunity, the challenges we face in getting there and what BC can do to overcome these challenges. 

According to Colijn, reaching herd immunity means vaccinating 80-90% of BC’s total population. This is slightly higher than the 75% currently pursued by Health Canada, because numerous factors, including variants, might still alter how effective the vaccines are. It’s also because researchers still don’t know the rate at which the virus will be transmitted when all restrictions are lifted.

“Herd immunity is a moving target,” Colijn said. “But it’s still a useful concept because we do want to achieve, through vaccination, protection from severe disease, protection from infection and protection from the transmission to those who are vulnerable around them.” 

According to Colijn’s modelling, only 51% of the BC population will receive protection through the current vaccination program because adults make up approximately 80% of BC’s population, but only 80% of these adults will be vaccinated. 

“Since we are not vaccinating those under 17, that means we’re getting zero in that group because they haven’t been approved yet,” said Colijn. “So even if we have 70-75% of the rest of us, we won’t be able to reopen completely to pre-pandemic levels.” 

The modelling looked at vaccinating 70% of people over 10 years old. It showed that this would be a significant step toward achieving herd immunity.

Schools have been a site of many COVID-19 exposures and outbreaks on Vancouver Island in recent weeks. As of April 19, there are 19 active school exposure notices on the Island Health website, 11 of which are in the Capital Regional District.

Currently, no COVID-19 vaccines have been approved for Canadians aged 16 and under. However, on April 16, Health Canada did say it’s reviewing a submission from Pfizer-BioNtech that expanded the use of their vaccine to those aged 12 and over. 

Vaccinating under-17s comes with a host of logistical and ethical challenges, all of which tie into bigger arguments about the general vaccine rollout. 

One challenge is figuring out who should be vaccinated first. Specifically, would it be more effective to vaccinate those who have many contacts—like high school students—or those who are older and have fewer contacts? 

Colijn said that their data supports a rollout based on contact, rather than age. 

Infections in schools have been increasing, possibly as a result of the new variants, while schools remain open throughout Vancouver Island.

Colijn also said high school students should be vaccinated to protect those around them—in part to protect the teens themselves, who may depend on parents’ good health to provide for them.

“Youths have a certain need for parents because parents are caregivers,” said Colijn. “So the damage of a youth infecting their parent so their parent has long COVID or can’t work or has severe symptoms or disease, that is a damage to the young people themselves.” 

For more of our conversation with Caroline Colijn, listen to our podcast on Apple Podcasts, Spotify or wherever you get your podcasts. For up-to-date coverage on the vaccine rollout, follow us on Twitter.