Pfizer and Moderna announced in recent days that they have vaccine candidates that are over 90 per cent effective in preventing the COVID-19 virus.
UW talk to Professor Kelly Grindrod, Canada’s Pharmacist of the Year and an expert in vaccines, to unpack which vaccine will work, the logistics of distributing them, and how long it will take for Canada and the world to go back to “normal.”
What is the difference between the Pfizer vaccine and the Moderna vaccine?
With the Moderna and Pfizer announcements over the last week, it appears we now have two promising vaccine candidates. Both vaccines use engineered RNA, which is a new approach for vaccine development. Pfizer’s vaccine is the result of a partnership with German biotech company BioNTech. Moderna, which is an American biotech company, developed their vaccine together with the U.S. National Institutes of Health as part of the country’s Operation Warp Speed program.
The vaccines appear to have similar efficacy, with the Pfizer vaccine claiming to be 90 per cent effective and Moderna claiming nearly 95 per cent efficacy. It is far too early to say if that 5 per cent difference is a true difference as these are still early days. However, a big difference worth noting for the Moderna vaccine is that it does not appear to require the ultra-low temperatures to be stored that we heard about with the Pfizer vaccine. This bodes well for both vaccines as it suggests mRNA vaccines can be manufactured to be stable at normal vaccine storage temperatures.
How likely is it that the Pfizer and Moderna vaccines announced recently will be effective in preventing COVID-19?
The announcement by both companies is promising but we need to be cautiously optimistic. The press releases shared that the vaccines are 90 to 95 per cent effective, but we need to be careful to avoid committing what is being termed “science by press release.” Everyone is now waiting to see more traditional scientific papers or reports, which will help us understand how much is known and what we still need to know. For example, we don’t know yet if older people respond as well to the vaccine as younger people. We don’t know how long the immunity conferred by the vaccines will last. However, these press releases are a glimmer of hope in an otherwise bleak time.
How will Canadians get access to the vaccine?
That’s the big question. Both vaccines require two doses, three to four weeks apart. So, for every person vaccinated, we need two doses. The Pfizer vaccine needs to be stored at very cold temperatures of around -70 C, which requires specialized freezers that are expensive to purchase and operate. The initial Pfizer press release raised many concerns that the vaccine wouldn’t be accessible to rural and remote locations or to developing countries who wouldn’t be able to store or transport it.
In contrast, Moderna has just announced that their vaccine appears to be stable for up to a month at regular fridge temperatures, and can be stored for up to 6 months at -20C. This may mean that the Pfizer vaccine could also be modified to be stored at more reasonable temperatures, or that the Moderna vaccine may be better suited to rural and remote locations.
How long will it take for people to be vaccinated and life to go back to “normal”?
The hope is that in early 2021 we should be starting to see frontline healthcare workers getting vaccinated. The push right now is to have a broad definition of “front line” to make sure we include doctors, nurses, and pharmacists, but also those in low paid healthcare positions who have high infection rates, such as personal support workers, nursing aids, and hospital cleaning staff. By having a broad definition of “healthcare worker”, the early vaccines would reach the hardest hit communities first.
The next step will likely focus on essential personnel who have a high risk of exposure to the virus, such as grocery store employees, taxi and bus drivers, transport truck drivers, school staff, and factory employees such as those working in meat processing plants. Long-term care residents and people living in congregate settings such as prisons and group homes will also likely be an early target as these tend to be the sites of wide-scale outbreaks. People who can work from home and are otherwise low risk are going to be the last to get the vaccine—but they are also the groups that have been the least likely to be infected. All in all, it could take a year to get back to normal.
The University of Waterloo has a number of experts available for comment on various aspects of the COVID-19 pandemic, click here to see the up-to-date list.
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