With COVID-19, whooping cough and mpox still a concern, what should Canadians do this fall?

After more than four years of living with COVID-19, one thing that’s predictable is that SARS-CoV-2 will continue to evolve rapidly and find new ways to infect and reinfect Canadians and the world’s population.

“KP.3.1.1 drove a notable summer surge in COVID-19 cases in Canada and the United States, as this virus continues to impact us differently than typical seasonal winter viruses like flu,” says Dr. Fiona Brinkman, Deputy in CoVaRR-Net’s Computational Analysis, Modelling and Evolutionary Outcomes (CAMEO) Pillar 6, and Distinguished Professor in Bioinformatics and Genomics at Simon Fraser University. “This subvariant has several new mutations that improve binding to our cells, increases transmissibility, and supports further immune evasion. While there are currently no concerns with new, emerging variants on the horizon, SARS-CoV-2 is still a relatively new virus and still has the potential to further optimize its cellular binding and immune evasion.”

The rapid rate of evolution of SARS-CoV-2 is still a concern. “SARS-CoV-2 has not gone away and looks like it’s here to stay,” says Dr. Nazeem Muhajarine, Co-Lead of CoVaRR-Net’s Public Health, Health Systems and Social Policy Impacts Pillar 8 and Professor, and epidemiologist, at the University of Saskatchewan. “Since 2020, each year, we have seen late summer surges of COVID-19 cases, and the current year was no different. This usually follows a winter surge of COVID-19 and other respiratory viral diseases as well,” he adds.

Get an updated vaccine this fall

Last fall, only 15% of Canadians aged five and up and fewer than half of higher-risk older adults had received an updated COVID-19 vaccine tailored to the XBB.1.5 variant by early December 2023, according to the Public Health Agency of Canada (PHAC). Newly updated COVID-19 vaccines from Moderna, Pfizer and Novavax, targeted to newer subvariants, have recently been approved by Health Canada. The new Moderna and Pfizer vaccines target the KP.2 subvariant of Omicron, which is much closer to the current dominant strain of KP.3.1.1 than the previous version of the vaccines. They are both approved for adults and children aged six months and older. The Novavax protein-based vaccine called Nuvaxovid is approved for adults and for children 12 years and older.

The National Advisory Committee on Immunization (NACI) strongly recommends that all Canadians at increased risk of SARS-CoV-2 infection or severe COVID-19 disease get the most recently updated vaccine this fall. However, CoVaRR-Net experts suggest everyone eligible aged five and up should get a booster.

“If it’s been six months since your last booster and you haven’t been infected with COVID-19 during that period, get the updated vaccine as soon as it’s available. The new formulation should provide some protection against infection and good protection against severe disease since it’s a better match for the dominant variant circulating now,” advises Dr. Cory Neudorf, MD, Co-Lead of CoVaRR-Net’s Public Health, Health Systems and Social Policy Impacts Pillar 8, and Professor at the University of Saskatchewan.

“Getting an updated booster this fall is especially important for individuals who are at higher risk due to age, an underlying medical condition, pregnant, living in a long-term care home or other congregate setting, Indigenous Peoples, members of racialized and other marginalized communities, and people who provide essential community services,” he says.

CoVaRR-Net experts also strongly advise parents that all eligible children and adolescents from age five to 17 should receive an updated vaccine this fall if they haven’t had a recent SARS-CoV-2 infection this year. This can both benefit their child and help limit widespread transmission in schools. Fewer than 7% of school-age children and teens had received an XBB.1.5 booster by June 2024, according to PHAC, enabling transmission in the school environment.

“SARS-CoV-2 is still so new and not much is known about the long-term effects of COVID on a child, especially if reinfected multiple times,” says Dr. Brinkman. “As parents, we want our children to have the best start in life, and vaccination can help minimize risks to their future health, as they venture out and explore their world.”

Dr. Brinkman also advises that those at higher risk of COVID-19 complications, who usually have lower rates of exposure and haven’t had COVID-19 recently, consider timing their vaccination this fall to be roughly two to eight weeks before any higher risk activity, including travel, if possible.

The reality is that people are still getting sick and dying from COVID-19. “People are presenting to physicians and hospitals during the current surge and there is still a certain amount of severity to this disease, resulting in intensive care unit (ICU) admissions and deaths,” adds Dr. Neudorf. “Also, the research continues to show the risk for long-term complications – or Long COVID – increases the more times you are sick.”

Stay home, if sick

It’s also important to take common sense precautions to prevent or limit the spread of all respiratory viruses, noting most spread more easily in the fall and winter. “If you have significant respiratory symptoms or fever, stay home if you’re sick,” says Dr. Neudorf. “We don’t need to spread any of these viruses in the community, schools or the workplace. If you’re sick or still recovering, do what you can to contain the spread, such as limiting contact with others and wearing a mask if around vulnerable people.”

Meantime, whooping cough, a bacterial illness also known as pertussis, is surging in Quebec, Ontario, New Brunswick and other provinces, just in time for back-to-school and ahead of the fall respiratory illness season. “We’re now seeing more whooping cough outbreaks in Canada. Unfortunately, the fact that many children have not been getting all their childhood vaccinations since the pandemic has opened the door for infectious diseases like whooping cough and measles to return. These diseases can be prevented with higher uptake of long-established, proven vaccines, that most people born in Canada have gotten for decades,” says Dr. Muhajarine.

What about mpox and bird flu?

On August 14, the World Health Organization (WHO) declared mpox a public health emergency of international concern, partly driven by the spread of mpox strain clade 1b in the Democratic Republic of Congo (DRC) and many other African countries. Clade 1b sometimes causes severe illness or death and is more transmissible than the clade 2 strain (which fueled a global outbreak in 2022) since people can get clade 1b not only through sexual contact but when handling personal items used by an infected person.

“Canada needs to do more in the international public health arena and advocate for delivery of mpox vaccines to hot spots in Africa where mpox is spreading. We haven’t had any reports in Canada of clade 1b as yet, but, in a globalized world, this strain is as close to us as the next visitor with the infection from a country where there is an outbreak,” says Dr. Muhajarine.

Influenza A H5N1– a subtype of avian influenza (“bird flu”) – made headlines last spring when it was reported the virus had jumped from birds into cattle in Texas, eventually causing outbreaks on dairy farms in multiple US states, spilling back into other animal species and infecting dairy farm workers. On August 30, new outbreaks of bird flu in cattle on dairy farms in California were confirmed and then on September 6, the US Centers for Disease Control and Prevention reported that a Missouri man was hospitalized with – and recovered from – the first case of human bird flu with no known work-related exposure to sick animals.

“The spread of bird flu to cattle herds in California is a concern because that state has the largest number of dairy farms in the U.S. and supplies roughly 20 per cent of that country’s milk,” Dr. Brinkman cautions. “Fortunately, in Canada, there are no confirmed cases of H5N1 in cattle yet and active monitoring of our milk supply for signs of the virus has been performed. We’re continuing to watch the spread and evolution of this new subclade of H5N1 very closely, including its spread this coming fall and winter when regular seasonal flu cases are added to the mix. Monitoring on multiple fronts is critical so we can quickly responding to, and hopefully minimize, any threats, and allow people to go about their normal lives,” she emphasizes. “But one of the simplest and effective ways individuals can reduce their risk of multiple viruses is to simply keep themselves, and their household members, up to date with recommended vaccines.”