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The first shots of the Pfizer-BioNTech COVID-19 vaccine were administered on Monday in Canada. While it made for a historic moment, the vaccine’s arrival has also resulted in a lot of questions about its efficacy and nationwide availability. The Ontario Medical Association (OMA) hosted a virtual panel on Monday to address the top 10 questions doctors get asked about the vaccine. Moderated by Samantha Hill, OMA president, the panel gathered five doctors to discuss what to expect from the vaccine as it makes its way across the province in the coming days. While these answers are specific to Ontario, much of what they address will be helpful information, no matter where you live.
Dr. Zain Chagla, infectious disease physician at St. Joseph’s Healthcare in Toronto, pointed to the four groups identified by the federal framework for vaccine rollouts: long-term care workers that provide care for seniors, Canadians 70 years of age and older (beginning with adults 80 years and older), healthcare workers in direct contact with patients including those in healthcare settings and personal support workers, and adults in Indigenous communities. “The hope is all these groups get the first batch of vaccines up till March, and then it starts seeping out to the general population after that,” Chagla says.
The vaccine will be distributed at a few centres across the province, says Dr. Isaac Bogoch, infectious disease consultant and general internist at the University Health Network. There are currently two centres in the province that are distributing the vaccine, and that will (most likely) expand to 13 other centres across the province. “We know this Pfizer vaccine doesn’t travel well. That’s why, at least up front, we’re going to be bringing people to the centres rather than bring the vaccine to people,” Bogoch says. Health Canada is expected to approve another vaccine—the Moderna vaccine—by month’s end. It’s known to be a more stable product that’s easier to be moved around, as it doesn’t need to be kept in extremely cold temperatures like the Pfizer vaccine, which must be kept at -70 C to be effective. This vaccine is said to be key to immunizing long-term care residents in Ontario. “When we have access to [the] vaccine, I think we can start to see the vaccine programs roll out in the communities themselves … it can be brought to more rural, remote and underserved locations.”
According to data from Pfizer and BioNTech, Chagla says we start seeing protection show up in the first 10 to 14 days after getting the first shot, but it doesn’t mean we can only get one shot and call it a day. “We do need two shots because this is still a vaccine that’s built on this two-dose series, where when they did the phase-one trials they found the best dose optimization to get the best response was those two shots 21 days apart.” Knowing the seriousness of COVID-19, Chagla says we have an obligation to ensure we get both shots correctly for optimal immunity across the population.
“As with any vaccine, you’re going to start to experience some symptoms, which might make you think about what it’s like to actually have the illness,” says Dr. Zainab Abdurrahman, a pediatric immunologist. The vaccine works by introducing little bits of a pathogen to your system so that your body thinks it’s getting infected and is able to produce an immune response. For some people, this might look like an elevated temperature—a natural immune response to try and kill viruses. Other side effects might include aches and pains, localized redness and some swelling at the site, which are all signs of your innate immune response and an indication that your immune system is working. The hope is that as your body makes immune responses, the next time you’re exposed you’ll have the ability to generate these antibodies to tackle the infection.
In the United Kingdom, where the vaccine was first rolled out, there were two cases of anaphylaxis (or serious allergic) reactions. Those patients were treated and recovered quickly, but Abdurrahman says the public health team in the U.K were initially a bit restrained with their recommendations of who can receive the shot while investigating this, and they put out a statement to that effect. “But with review of all the information, all the data looking at those in the [Pfizer] studies, there was actually no increased risk of having anaphylaxis in this vaccine compared to others. It's important for everyone to know that people who had food allergies and had other allergies were included in the [Pfizer] study,” she added. The only people excluded were those with allergies to components in the vaccine.
With this information, the U.S. Food and Drug Administration as well as Health Canada have recommended that people who have an allergic reaction to the first dose of the two-dose Pfizer vaccine should not get the second dose, stating as well that it is not safe for those who are allergic to one of its components—such as polyethylene glycol. The Canadian Society of Allergy and Clinical Immunology released a statement on Tuesday that acknowledged the two cases in the UK and went on to “emphasize that the majority of individuals with a history of allergy will be able to safely receive vaccination for COVID-19.”
Abdurrahman notes that people who are pregnant and immunocompromised generally need to be more cautious with all vaccines—especially live vaccines. This includes the flu vaccine, which is basically made from weakened influenza viruses— because there’s an increased risk they could develop symptoms and have a milder form of the infection. However, the COVID-19 vaccine is not a live vaccine, so it does not have that increased risk. But because pregnant women were excluded from COVID-19 clinical trials, there is currently no safety data for this group. The Centers for Disease Control and Prevention (CDC) recommends those who are immunocompromised, pregnant or breastfeeding discuss the risks and benefits of the vaccination with their healthcare providers.
The vaccine tells your body to make a spike protein, explains Dr. Vinita Dubey, Toronto Public Health’s associate medical officer of health—a piece of the COVID virus that is responsible for infection. Essentially, a spike protein is a piece of protein that your body makes antibodies against, but it’s not the whole virus—”and so that’s why the virus can’t give you COVID,” Dubey says (though the spike protein is enough to make your body think that it’s infected). Your immune system responds to the spike proteins by making antibodies that fight off infection. The antibodies break down the spike protein and the vaccine, and the antibodies you’re left with then protect you if you’re exposed to COVID.
Bogoch says we don’t know the answer to that quite yet. “We’ve only started using this particular product in humans since March when the first phase one clinical trials began, so we don’t actually know how long protection will last.” Whether or not we’ll need to take it annually like the flu shot is also something that will reveal itself with time, though Bogoch emphasizes that this vaccine is very different from the flu vaccine. (As mentioned, the COVID vaccine is not a live vaccine.)
“That’s a pretty loaded question,” says Dr. Mariam Hanna, a pediatric allergist. “Vaccine safety, if we take a step back, is heavily scrutinized in any vaccines that we have on the market.” While vaccine safety is first established in clinical trials, people often overlook that it continues to be analyzed in real time. In relation to the Pfizer vaccine, researchers looked for rare side effects in the 44,000 doses administered as part of the clinical trials. As we get into the real-world data, there will be more cases to analyze—like the two anaphylaxis reactions in the U.K.
Vaccine safety monitoring happens on a local, provincial, national and international level. “We know it's safe, we continue to gather data to ensure that it's safe. The real-world data is probably the most exciting part to look at as vaccines get implemented. So that when it's your turn to get the vaccine, the safety data is not only 44,000 patients, it's in the millions by that point,” Hanna says.
As it stands, the available vaccine is approved in people 16 years and older. Hanna says we do have clinical trials underway in pediatrics for 12 to 15, as well as for those under 12. “As is the process with many vaccines as they’re developed, their first established safety is in adults and then we start looking at pediatric trials.”
Children make up 20 percent of Canada’s population, and we will not achieve herd immunity until they’re able to be vaccinated as well. “First and foremost, we need to continue to keep our guard up during this transition time. Kids are not included in the phase-one rollout, maybe in phase two, but probably phase three will definitely include kids. So until then, we refer to the three guards that we have: physical distancing, masks and hand hygiene. But COVID vaccines for [adults] that can get them,” Hanna says.
To the questions of whether you still need to wear a mask and stay home after you get the vaccine, Dubey says the simple answer is yes and yes. While the doctors are optimistic and have seen a high efficacy rate based on early trials, Dubey reiterates that it still takes time. “It's not overnight, it still can take months or even years. And I think part of that is because we have to get everyone vaccinated and that's going to take time as well. So in the meanwhile, we're going to wear a mask and physical distance, stay home if we’re sick, we're going to screen [our] before we send them to school, we're going to do all of these things,” she says. Protecting the vulnerable—those who live in shelters, long-term care homes, those who may suffer more serious consequences should they get COVID—means we must give everyone a chance to get vaccinated.