KITCHENER -- Getting your first dose of a COVID-19 vaccination doesn't mean you can start to gather outside of your immediate household right away, according to a vaccine expert from the University of Waterloo.

Dr. Kelly Grindrod, an associate professor in UW's School of Pharmacy, spoke about COVID-19 vaccines and how it could impact immunity to the disease at the Region of Waterloo's COVID-19 briefing on Friday morning.

"By far and away, the number one question that I've been getting is 'When can I hug my grandkids again?'" Grindrod said.

Grindrod said the community is in "a funny time right now" as vaccination efforts ramp up across Ontario.

"We're vaccinating the oldest in our population as one of the priority groups," she said at the briefing. "What that means is there's going to be an awful lot of vaccinated grandparents, but at the same time the last people who are going to be vaccinated are children."

Currently, only a minority of people have been vaccinated against the disease and the majority of the population has no protection.

Researchers are working on clinical trials for vaccinating people as young as 12, and Grindrod said trials for children older than six months were recently approved. She's hopeful that means people in that age group might be vaccinated in late summer or early fall.

"That, for the most part, is when you're looking really at whole populations being able to mask-free hug their grandkids," Grindrod said.

Grindrod said people who have received ether one or both doses of their COVID-19 vaccine often feel good. She added those vaccines are very good at preventing serious illness, hospitalization and death.

"That is the goal of vaccinating people," she said. "What separates COVID from a cold is colds don't give you severe illness, hospitalizations and death."

All vaccines approved for use in Canada are effective in preventing bad outcomes like hospitalizations and death, Grindrod said. However, improved immunity doesn't happen right away and no vaccine is 100 per cent effective.

"We vaccinate the entire population," she said. "By having the majority of people have immunity, those who don't develop immunity, there's no community spread and they're protected by the group."

According to Grindrod, there's no way of knowing right now if the vaccine has effectively built up a person's immunity to COVID-19.

"About two-thirds of people, give or take, are protected after two to three weeks after they've their first dose of vaccine," Grindrod said. "Those numbers, even after the first dose, appear to climb to 80 per cent, even almost as high as 90 per cent after the first dose, within about four to six weeks."

Based on current vaccine rollout, Grindrod said that means most people who have received a first dose won't be able to see their grandkids over Easter.

"The majority of people have not been vaccinated long enough to have that immunity," she said.

TAKE THE FIRST VACCINE AVAILABLE TO YOU

When it comes to vaccine ability, Grindrod said the best vaccine is the one that's available to you first.

"What we do know, looking at the data, is all the vaccines approved in Canada are really effective for severe illness, hospitalization and death," Grindrod said. "As we head into the third wave and as we look at the variants, that is the concern."

"You're not choosing between vaccines, you're choosing between getting vaccinated or waiting unvaccinated in a third wave with variants."

Grindrod also addressed concerns about blood clot concerns reported in relation to AstraZeneca vaccines in Europe.

"One thing to remind people is COVID causes clots," she said. "About one in 100 people who have COVID develop a clot. One in 20 people who are hospitalized due to COVID develop a clot."

Whether or not clots are a side effect of the AstraZeneca vaccine is still under investigation, but Grindrod said the incidence is about one in 250,000 people, which is a similar statistic for side effects from birth control pills.

"If you want to avoid a clot, the best thing you can do right now is avoid COVID by getting vaccinated," Grindrod said.