Although the U.S. will soon offer COVID-19 vaccine booster shots to the general population, Canadian experts aren’t sure that Canada should follow suit.
The U.S. Centers for Disease Control and Prevention made the announcement Wednesday that they are planning to offer a third dose of the Pfizer and Moderna vaccines to Americans, eight months after they had their second dose.
They expect to start offering booster shots to people in September, as Americans who received their shots first become eligible. The overall plan is awaiting a Food and Drug Administration evaluation of the safety and effectiveness of a third dose, the officials said.
The CDC decision was expected, said Alyson Kelvin, a Canadian vaccinologist who works with the Vaccine and Infectious Disease Organization in Saskatoon, but she’s not sure it’s the right one. “Looking at the evidence, I think that many scientists are conflicted whether or not the general public does need booster shots,” she said.
The CDC points to three pre-print studies released Wednesday that examined how well vaccines protected against infection and hospitalization with COVID-19 in the real world. However, all three studies measure vaccine effectiveness over a period before and after the Delta variant became the predominant COVID-19 variety in the U.S..
In other words, it’s hard to tell from these studies whether increasing case numbers are due to people’s immunity fading over time, or whether it’s due to vaccines being less effective against the Delta variant.
“This study could not differentiate the independent impact of the Delta variant from other factors, such as potential waning of vaccine-induced immunity,” reads one study, which examined people in nursing homes. “Further research on the possible impact of both factors on VE (vaccine effectiveness) among nursing home residents is warranted.”
1:18 Ontario to offer 3rd COVID-19 shot to ‘vulnerable’ populations, 1st shot to ages 12+
Ontario to offer 3rd COVID-19 shot to ‘vulnerable’ populations, 1st shot to ages 12+
Waning immunity?
To some leading scientists, the studies “would not be sufficient, in and of themselves, to make the case for a booster,” said Dr. William Schaffner, an infectious-diseases expert at Vanderbilt University, and a liaison to an expert advisory panel that helps the CDC form its vaccination recommendations.
Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, noted that other studies looking at antibodies suggest that immunity fades over time and higher antibody levels might be needed to combat the Delta variant. Giving a third dose causes a “dramatic increase” in antibody levels, he said.
Even though it is calling for a booster shot, the CDC emphasized that the vaccine remained effective against catching COVID-19 and helped prevent serious outcomes from the disease. “While we are still learning about how these vaccines perform over time and how long they will last against emerging variants, one thing is very clear: Getting vaccinated can keep you out of the hospital. Getting vaccinated can save your life,” said CDC director Dr. Rochelle Walensky.
In recent weeks, several other countries have decided to offer booster shots to older adults and people with weak immune systems, including Israel, Germany and France. European Union officials said on Wednesday they do not yet see a need to give booster shots to the general population.
“I think that there’s some evidence that immunity does wane,” Kelvin said. “This happens with all vaccines or even infections.”
When it comes to new variants though, Kelvin isn’t sure how much a third dose of the exact same vaccine will help. “Is this a boost of the same vaccine or is this a boost that’s matching the most prominent circulating variant?” she asked.
If your antibodies are different from the circulating virus, “It doesn’t matter if you get another vaccine to the original SARS-CoV-2 spike protein because it’s a mismatch already,” she said.
1:53 Canada’s top doctor says discussion on COVID-19 booster shots still ‘evolving’
Canada’s top doctor says discussion on COVID-19 booster shots still ‘evolving’ – Aug 5, 2021
Reaching the right people
The Public Health Agency of Canada didn’t respond to specific questions about the CDC decision by deadline, however it noted that people in specific populations who are immunosuppressed might not mount as strong a defence against the virus as others after they get vaccinated. The National Advisory Council on Immunization is reviewing evidence for a booster shot in this population, PHAC said, and will update its recommendations “in the coming weeks.”
People who take immunosuppressant drugs, such as organ transplant patients who take them so they don’t reject their new organs, often have weaker responses to vaccines, said Dr. Deepali Kumar, director of transplant infectious diseases at the University Health Network in Toronto.
“It’s not surprising that that the response to mRNA vaccines would be low in immunocompromised people, and third doses seem to somewhat overcome that problem,” she said. “If a transplant patient gets COVID, they are more likely to end up in the hospital, more likely to end up in the ICU and more likely to die. And so this is a population that we really need to protect.”
Ontario recently announced that it will give booster shots to certain at-risk populations, and other provinces are considering similar measures.
Until we have more specific data though, Kelvin thinks that Canada’s vaccination focus shouldn’t be on giving third doses to fully-vaccinated people in the general population.
“Helping vaccines reach underserved communities in North America is really going to help us achieve our goal of reducing COVID-19 infections,” she said. She thinks it’s more important to reach people who haven’t gotten their first and second doses.
“My perspective as a vaccinologist would be: trying to get as much vaccine coverage both in areas of North America as well as all over the world, is going to help bring down the virus circulating and the number of COVID-19 cases that we’re seeing.”
Kumar agrees. “We need to focus on making sure that the first and second doses are in people’s arms first,” she said. “I mean, we still have a good proportion of the younger population that hasn’t had their first or second doses. So I think, if we’re going to stop the pandemic, we need to cast a broad net and make sure that that everyone’s vaccinated.”
The Canadian government says it will donate up to 200,000 vaccine doses to fight the mpox outbreak in Congo and other African countries.
It says the donated doses of Imvamune will come from Canada’s existing supply and will not affect the country’s preparedness for mpox cases in this country.
Minister of Health Mark Holland says the donation “will help to protect those in the most affected regions of Africa and will help prevent further spread of the virus.”
Dr. Madhukar Pai, Canada research chair in epidemiology and global health, says although the donation is welcome, it is a very small portion of the estimated 10 million vaccine doses needed to control the outbreak.
Vaccine donations from wealthier countries have only recently started arriving in Africa, almost a month after the World Health Organization declared the mpox outbreak a public health emergency of international concern.
A few days after the declaration in August, Global Affairs Canada announced a contribution of $1 million for mpox surveillance, diagnostic tools, research and community awareness in Africa.
On Thursday, the Africa Centres for Disease Control and Prevention said mpox is still on the rise and that testing rates are “insufficient” across the continent.
Jason Kindrachuk, Canada research chair in emerging viruses at the University of Manitoba, said donating vaccines, in addition to supporting surveillance and diagnostic tests, is “massively important.”
But Kindrachuk, who has worked on the ground in Congo during the epidemic, also said that the international response to the mpox outbreak is “better late than never (but) better never late.”
“It would have been fantastic for us globally to not be in this position by having provided doses a much, much longer time prior than when we are,” he said, noting that the outbreak of clade I mpox in Congo started in early 2023.
Clade II mpox, endemic in regions of West Africa, came to the world’s attention even earlier — in 2022 — as that strain of virus spread to other countries, including Canada.
Two doses are recommended for mpox vaccination, so the donation may only benefit 100,000 people, Pai said.
Pai questioned whether Canada is contributing enough, as the federal government hasn’t said what percentage of its mpox vaccine stockpile it is donating.
“Small donations are simply not going to help end this crisis. We need to show greater solidarity and support,” he said in an email.
“That is the biggest lesson from the COVID-19 pandemic — our collective safety is tied with that of other nations.”
This report by The Canadian Press was first published Sept. 13, 2024.
Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.
HALIFAX – The Nova Scotia government says it could be months before it reveals how many people are on the wait-list for a family doctor.
The head of the province’s health authority told reporters Wednesday that the government won’t release updated data until the 160,000 people who were on the wait-list in June are contacted to verify whether they still need primary care.
Karen Oldfield said Nova Scotia Health is working on validating the primary care wait-list data before posting new numbers, and that work may take a matter of months. The most recent public wait-list figures are from June 1, when 160,234 people, or about 16 per cent of the population, were on it.
“It’s going to take time to make 160,000 calls,” Oldfield said. “We are not talking weeks, we are talking months.”
The interim CEO and president of Nova Scotia Health said people on the list are being asked where they live, whether they still need a family doctor, and to give an update on their health.
A spokesperson with the province’s Health Department says the government and its health authority are “working hard” to turn the wait-list registry into a useful tool, adding that the data will be shared once it is validated.
Nova Scotia’s NDP are calling on Premier Tim Houston to immediately release statistics on how many people are looking for a family doctor. On Tuesday, the NDP introduced a bill that would require the health minister to make the number public every month.
“It is unacceptable for the list to be more than three months out of date,” NDP Leader Claudia Chender said Tuesday.
Chender said releasing this data regularly is vital so Nova Scotians can track the government’s progress on its main 2021 campaign promise: fixing health care.
The number of people in need of a family doctor has more than doubled between the 2021 summer election campaign and June 2024. Since September 2021 about 300 doctors have been added to the provincial health system, the Health Department said.
“We’ll know if Tim Houston is keeping his 2021 election promise to fix health care when Nova Scotians are attached to primary care,” Chender said.
This report by The Canadian Press was first published Sept. 11, 2024.
ST. JOHN’S, N.L. – Newfoundland and Labrador‘s chief medical officer is monitoring the rise of whooping cough infections across the province as cases of the highly contagious disease continue to grow across Canada.
Dr. Janice Fitzgerald says that so far this year, the province has recorded 230 confirmed cases of the vaccine-preventable respiratory tract infection, also known as pertussis.
Late last month, Quebec reported more than 11,000 cases during the same time period, while Ontario counted 470 cases, well above the five-year average of 98. In Quebec, the majority of patients are between the ages of 10 and 14.
Meanwhile, New Brunswick has declared a whooping cough outbreak across the province. A total of 141 cases were reported by last month, exceeding the five-year average of 34.
The disease can lead to severe complications among vulnerable populations including infants, who are at the highest risk of suffering from complications like pneumonia and seizures. Symptoms may start with a runny nose, mild fever and cough, then progress to severe coughing accompanied by a distinctive “whooping” sound during inhalation.
“The public, especially pregnant people and those in close contact with infants, are encouraged to be aware of symptoms related to pertussis and to ensure vaccinations are up to date,” Newfoundland and Labrador’s Health Department said in a statement.
Whooping cough can be treated with antibiotics, but vaccination is the most effective way to control the spread of the disease. As a result, the province has expanded immunization efforts this school year. While booster doses are already offered in Grade 9, the vaccine is now being offered to Grade 8 students as well.
Public health officials say whooping cough is a cyclical disease that increases every two to five or six years.
Meanwhile, New Brunswick’s acting chief medical officer of health expects the current case count to get worse before tapering off.
A rise in whooping cough cases has also been reported in the United States and elsewhere. The Pan American Health Organization issued an alert in July encouraging countries to ramp up their surveillance and vaccination coverage.
This report by The Canadian Press was first published Sept. 10, 2024.
