Answers regarding COVID-19 variants and vaccine mixing

Prince Edward Family Health Team.

Editor’s note: A recent Ipsos poll indicated nearly 20 per cent of Canadians are either hesitant or out right refusing to take any COVID-19 vaccination. The following is a submission for the Prince Edward Family Health Team Communications Committee

More of your COVID-19 vaccine questions answered – Variants and vaccine mixing:

Q: Why is there so much concern about the latest virus variant called Delta?

A: The Delta variant, originally identified in India, is now rapidly spreading around the world and causing outbreaks even in countries where COVID had been well controlled. This variant is six times more transmissible than the original virus. Even seconds of unmasked contact can be enough to spread it. Unvaccinated people who get the Delta variant are twice as likely to be hospitalized with severe COVID. A single shot of a vaccine is much less effective against Delta, but two shots still provide very good protection.

Q: What is going to be our best way of preventing the Delta variant from running wild?

A: Getting as many people fully vaccinated as quickly as possible is essential. Even if you are fully vaccinated, continue to wear masks and follow social distancing guidelines. Consider limiting your interactions with people from high risk areas. Rarely, people who are fully vaccinated have been infected with the Delta variant. Generally, they have mild or asymptomatic illness, but they can still spread the virus to unvaccinated people. People who are at high risk need to be particularly careful.

Q: Why are we sometimes being offered a different vaccine for our second shot?

A: Getting a different vaccine for booster shots is common with many vaccines and may happen for many reasons. Sometimes it is because of what is available at the time and sometimes it might be because it gives better protection.

Q: Why does everyone know about Pfizer but the Moderna name is less well known?

A: Both vaccines were developed by small companies that specialized in mRNA technology. Most of the initial Moderna production was purchased by the US government and was not distributed internationally at first. Pfizer was already established internationally so was able to distribute vaccine globally including Canada. These two vaccines are very similar and they both provide excellent protection.

Q: Why is it OK to switch between Pfizer and Moderna?

A: These vaccines are functionally the same. They both teach the body to make antibodies against the COVID virus spike protein using the same mechanism. This means that you get the same response from either shot – whether it is Pfizer or Moderna. Whether or not there is any added benefit to getting one shot of each is still being studied.

Q: What about getting an mRNA after Astra Zeneca?

A: In this case, mixing an mRNA vaccine – like Pfizer or Moderna, with a viral vector vaccine like AZ triggers a broader immune response as they each activate slightly different parts of the immune system. This may provide even greater protection against COVID. Bottom Line, two doses of any of our vaccines gives you excellent protection against all of the variants currently that are circulating in Canada.