COVID-19 provokes all sorts of questions. Can I see my grandchildren after the first dose? How does the first vaccine shot affect risk of severe COVID? When will vaccinations push down ICU admissions? Every week Medcan’s Medical Advisory Services team of expert physicians get together to discuss trending topics. They develop advice to share with their corporate clients, which include some of the world’s biggest brands. The docs are witty, and the meetings entertaining, but more to the point they feature up-to-the-minute guidance of the sort that we’re all craving. So we recorded one of their sessions and cut it into an episode.

Featured in this episode is Medcan chief medical officer Dr. Peter Nord, clinical director of travel medicine Dr. Aisha Khatib, senior medical consultant Dr. Matthew Burnstein, associate medical director Dr. Jason Abrams and Dr. Alain Sotto, who, in addition to his role at Medcan, is also the occupational medical consultant for the Toronto Transit Commission.

To enlist the services of Medcan’s Medical Advisory Services, email corporatesales@medcan.com.

INSIGHTS

It’s not yet known how likely a partly or even fully vaccinated person is to transmit the coronavirus, says Dr. Aisha Khatib. “So we really still need to maintain those public health measures to help decrease the risk of entering into a bigger fourth or even fifth wave down the road. Plus, Dr. Nord says, no vaccine is 100% effective. “We're assuming that there is a reduced transmission with vaccination, but we don't know that for sure.” In other words, some risk will remain that even the fully vaccinated can transmit the virus. (5:00)

The variants of concern continue to live up to their name. According to Dr. Alain Sotto, case fatality rates have tripled among 20-29 year olds for those in Brazil infected by the P.1 variant, from 0.04% to 0.13%. Dr. Nord points out that an outbreak of P.1 is ongoing in British Columbia and that, while the vaccine does appear to be protective against current variants, some risk does exist for future variants to require additional vaccination measures. (7:25)

Speaking about VIPIT, or the Vaccine-Induced Prothrombotic Immune Thrombocytopenia associated with the AstraZeneca and Johnson & Johnson vaccines, Dr. Jason Abrams puts the relative dangers in perspective. Risk of blood clots is higher for those taking the oral contraceptive pill, or those who smoke, compared to the blood clot risk from the AstraZeneca vaccine, Dr. Abrams says. “Frankly a lot of people are not getting the AstraZeneca vaccine—they are waiting,” agrees Dr. Nord. “And what people have to understand is that there’s risk associated with that as well.” (9:30)

Rapid antigen tests like the Abbott Panbio, which provide results in about 15 minutes based on a nasal swab, should be one of the mainstays of preventing outbreaks at workplaces, says Dr. Alain Sotto. The test protocol also provokes questions from the curious. People are wondering: Will those who have been vaccinated produce a positive result on a rapid antigen tests? The answer, Dr. Sotto says, is no. Later, Dr. Khatib says that rapid antigen tests will detect cases that are too early in their infection cycle to be symptomatic. In fact, she argues that screening with the tests may have prevented the Amazon warehouse outbreak. (13:15, 16:50)

More clarification about what you can change after you get your first dose: According to Dr. Sotto, the first dose provides about 80% efficacy in the real world. Dr. Nord clarifies: About 80% of the people given their first doses did not receive any symptoms of COVID-19 infection. But unfortunately, Dr. Burnstein says, the first shot does not change your behaviour. Internally, the first dose makes people feel less anxious about getting infected, because they are more protected than they were before. But externally they shouldn’t change their behaviour at all. (23:00)

Dr. Khatib serves in a COVID-19 testing centre and has personally encountered people who have tested positive for the virus after they received both the first and second doses of the vaccine. They’ve tended to have no symptoms, or very mild symptoms. “But the question is, are they going to be at risk to pass that on to the next person?” Dr. Khatib asks, with the implication that transmission after vaccination is possible. (28:25)

How long are we protected against COVID-19 after being fully vaccinated? Dr. Abrams says that researchers don’t actually know how long the immunity lasts yet. “The results so far based on studies are encouraging,” says Dr. Abrams, “that there is protection of at least several months.” Which raises the question: Are we going to need booster shots to maintain immunity against COVID-19 at some point in the months or years after we’ve been fully vaccinated? Dr. Khatib believes the likelihood is high. The COVID booster could even be an annual thing, like the flu shot. (29:20)

LINKS

Referenced in this episode is this CMAJ article about rapid antigen testing by Dr. Isaac Bogoch and others, which argues for the mass deployment of the point-of-care tests as a public health strategy to minimize COVID outbreak risk.

Here’s information about Medcan’s rapid antigen testing service.

A news report about the outbreak in the Amazon warehouse mentioned in the episode.

Additive to the rapid antigen testing content in this episode is Joshua Gans’ essay, “What does vaccination mean for rapid screening?”

The Takeaway is the YouTube video series that features Medcan docs providing guidance on trending medical topics. This one provides Dr. Nord’s advice on the AstraZeneca vaccine, and whether to get it. Link.

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