The summer wave is upon us. In several parts of the country, COVID-19 cases and sewage levels are rising again in a new spike due to the highly contagious Omicron BA.4 and BA.5 subvariants. For Canadians living with the reality of the pandemic for more than two years, asking about masks and vaccines is no longer a question. Here’s what Canadians need to know about the new subvariants, getting boosters and the possibility of reinfection.
What do we know about Omicron’s BA.4 and BA.5 subvariants?
Omicron subvariants BA.4 and BA.5, which were first detected in South Africa in January and February 2022, are causing a wave of cases in several provinces. BA.5 is poised to become the dominant variant strain. The good news is that BA.4 and BA.5 do not appear to cause more severe disease than previous versions of Omicron. “We don’t see BA.4 and BA.5 being more infectious or more pathogenic compared to the previous subvariants BA.1 and BA.2,” said Dr. Nazeem Muhajarine, a professor of community health and epidemiology at the University of Saskatchewan. However, he noted that because BA.4 and BA.5 are highly contagious, the sheer number of cases could put more strain on our healthcare system. Dr. Muhajarine pointed to the United Kingdom and France, where the surge caused by BA.5 is leading to an increase in hospitalizations. “We see what happens in Europe and it happens again in Canada three to four weeks later. This has been the pattern throughout the pandemic,” said Dr Muhajarine.
What are the symptoms of BA.4 and BA.5?
The symptoms of BA.4 and BA.5 are similar to the original Omicron variant, which differ from previous versions of COVID-19, said Raywat Deonandan, an epidemiologist and associate professor at the University of Ottawa. Symptoms of Omicron include fever, runny nose, cough, sore throat, aches, muscle aches and fatigue. Gastrointestinal symptoms and loss of smell and taste are not as prevalent as in earlier variants. “The most prevalent are cold-like symptoms, which is unfortunate because you can’t tell the difference between a cold and COVID-19,” Deonandan said. “But there’s so much COVID now, you can assume that if you have a cold, it’s probably COVID.”
How often can you be reinfected with Omicron?
BA.4 and BA.5 are both highly capable of evading vaccine-induced immunity and immunity acquired from previous COVID-19 infections. A British study published in the journal Science found that antibodies from BA.2 are less effective at neutralizing the BA.4 and BA.5 subvariants, leading to more reinfections. “So, in other words, if you were infected with a previous subvariant of Omicron, that’s not going to protect you from getting infected again with BA.4 and BA.5,” Dr. Muhajarine said. Research led by University of Toronto researcher Igor Stagljar found that immune protection gained from a vaccine or previous infection lasts only four months against BA.4 and BA.5. “If someone had COVID early this year, or if someone was vaccinated early this year, that means we have zero – almost zero – protection in the form of neutralizing antibodies,” against the new variants until the summer. Doctor Stagljar said. There are also many factors that can affect immunity, including age and pre-existing medical conditions, which could make someone more vulnerable to reinfection, Dr Muhajarine said.
How effective are the current Omicron vaccines?
Our current vaccines were adapted exclusively to the original virus. These vaccines are no longer effective in preventing infection against BA.4 and BA.5, Dr. Mahajarine said. However, he notes that they still offer great protection against serious illness and hospitalization. Vaccine makers Pfizer and Moderna are working on new bivalent boosters that target specific mutations in the spike protein found in both the old strain and the newer Omicron strain. While this custom formula isn’t expected to land until the fall, experts say it shouldn’t be considered outdated. “If we have, in this vaccine, representation from very different strains or different variants, then we can assume that we have broad protection against future variants as well,” said Dr Volker Gerdts, director and chief executive of the Vaccine and Infectious Diseases Agency. .
If I am already infected with COVID-19, should I get a booster?
Yes, the National Advisory Committee on Immunization (NACI) strongly recommends a booster dose for all adults and for adolescents considered at high risk for severe disease. Studies have also found that unvaccinated individuals previously infected with BA.1 were more likely to be reinfected with BA.4 and BA.5 compared to those who had been vaccinated. “The bottom line is that taking Omicron, for example, vaccination, is not a smart way to build immunity against re-infection with Omicron or another variant,” Dr Muhajarine said.
My age group is now eligible for a second reminder. Should I take it right away?
Amid the growing Omicron wave, provinces and territories across Canada have expanded eligibility for fourth doses. For example, in Ontario, everyone between the ages of 18 and 59 who received their last dose more than five months ago – and it’s been at least three months since their last infection – is now eligible for a second booster dose. Ontarians who receive a second booster dose will still be eligible in the fall for new bivalent vaccines that specifically target Omicron. Quebec, New Brunswick, Prince Edward Island, Yukon and Nunavut have also extended eligibility for fourth doses to all adults. When deciding when to get your fourth dose, Deonandan had simple advice for those who qualify: “Get it now. Do not hesitate. We spend so much time trying to figure out the optimal time to maximize our protection – it’s a fool’s game because the virus is all around us.” Dr. Muhajarine said to also assess your personal risk of exposure and need for protection. For example, if you plan to travel internationally to a country with high rates of COVID-19, you might consider getting your souvenir two to three weeks before you leave. Other personal circumstances, such as attending a wedding or returning to work, could also affect the timing of your souvenir. In addition, many health experts now say that receiving two doses of the vaccine should no longer be considered fully vaccinated. Instead, it should be considered a three-dose vaccine.
How soon after a COVID-19 infection should I get a booster?
NACI recommends that anyone infected with COVID-19 should wait three months before receiving a booster dose. A longer interval between infection and vaccination “may lead to a better immune response, as this allows time for that response to mature in breadth and strength, to reduce circulating antibodies, thereby avoiding immune interference when the vaccine is given.”
How effective are BA.4 and BA.5 masks indoors?
“High-filtration masks are very good at reducing both breathing in tiny viruses through your mouth and nose and, if you have the virus in your body, from shedding it into the air,” Dr Muhajarine said. Since COVID-19 is airborne, a quality mask – such as an N95 or KN95 – is one of the most effective and cheapest ways to reduce transmission, whether it’s a BA.4 or BA.5, or any other variant . he said. Although most mask mandates have been lifted across the country, many health experts recommend wearing masks on public transportation and in grocery stores or other crowded indoor spaces. Some health professionals are even calling for the reinstatement of indoor mask use requirements. “We need to stay on our masks a little longer because they really do protect us and others around us,” Dr Muhazarin said. Rapid tests can still detect BA.4 and BA.5, but their use comes with caveats. Jeff McIntosh/The Canadian Press
Are rapid tests still accurate with Omicron?
Yes, rapid tests can still detect BA.4 and BA.5, but their use comes with caveats. Unlike PCR tests, which amplify small amounts of genetic material to confirm the presence of the SARS-CoV-2 virus, rapid tests detect the presence of proteins – or antigens – found on the surface of the virus. A sufficiently high concentration of the virus is required to produce a positive result with the rapid test. If you have symptoms and test negative on a rapid test, that doesn’t necessarily mean you’re in the clear, Deonandan said. “If you’ve been vaccinated and become infected with Omicron, you’ll develop symptoms before you get a viral load. That’s your vaccine doing its job – producing all that phlegm and mucus to prepare your body to fight that infection that’s coming,” he said. Deonandan recommends repeated tests over a few days. “If you test negative, you may still have a rapid infection.” However, if you test positive on a rapid test, Deonandan said you can trust that it’s likely to be accurate.
What treatments are currently available for COVID-19?
Health Canada has approved a handful of treatments for COVID-19, including drugs that reduce or prevent the virus from multiplying in human cells and drugs that treat the symptoms of COVID-19. Pfizer’s Paxlovid is an oral antiviral medicine approved to treat symptomatic adults with mild to moderate COVID-19 and who are at high risk of severe disease. Evusheld, which was developed by AstraZeneca, is designed to protect people with weakened immune systems, including transplant patients. Candidate patients must be unlikely to have an adequate immune response to COVID-19 vaccines or be among the few for whom vaccination is not recommended. Unlike Paxlovid, Evusheld is only approved for…
