Even people who have recovered from COVID-19 are urged to get vaccinated, especially as the extra-contagious delta variant surges — and a new study shows survivors who ignored that advice were more than twice as likely to get reinfected.
Friday’s report from the Centers for Disease Control and Prevention adds to growing laboratory evidence that people who had one bout of COVID-19 get a dramatic boost in virus-fighting immune cells — and a bonus of broader protection against new mutants — when they’re vaccinated.
“If you have had COVID-19 before, please still get vaccinated,” said CDC Director Dr. Rochelle Walensky. “Getting the vaccine is the best way to protect yourself and others around you, especially as the more contagious delta variant spreads around the country.”
According to a new Gallup survey, one of the main reasons Americans cite for not planning to get vaccinated is the belief that they’re protected since they already had COVID-19. From the beginning health authorities have urged survivors to get the broader protection vaccination promises. While the shots aren’t perfect, they are providing strong protection against hospitalization and death even from the delta mutant.
Scientists say infection does generally leave survivors protected against a serious reinfection at least with a similar version of the virus, but blood tests have signaled that protection drops against worrisome variants.
The CDC study offers some real-world evidence.
Researchers studied Kentucky residents with a lab-confirmed coronavirus infection in 2020, the vast majority of them between October and December. They compared 246 people who got reinfected in May or June of this year with 492 similar survivors who stayed healthy. The survivors who never got vaccinated had a significantly higher risk of reinfection than those who were fully vaccinated, even though most had their first bout of COVID-19 just six to nine months ago.
A different variant of the coronavirus caused most illnesses in 2020, while the newer alpha version was predominant in Kentucky in May and June, said study lead author Alyson Cavanaugh, a CDC disease detective working with that state’s health department.
That suggests natural immunity from earlier infection isn’t as strong as the boost those people can get from vaccination while the virus evolves, she said.
There’s little information yet on reinfections with the newer delta variant. But U.S. health officials point to early data from Britain that the reinfection risk appears greater with delta than with the once-common alpha variant, once people are six months past their prior infection.
“There’s no doubt” that vaccinating a COVID-19 survivor enhances both the amount and breadth of immunity “so that you cover not only the original (virus) but the variants,” Dr. Anthony Fauci, the U.S. government’s top infectious disease expert, said at a recent White House briefing.
The CDC recommends full vaccination, meaning both doses of two-dose vaccines, for everyone.
But in a separate study published Friday in JAMA Network Open, Rush University researchers reported just one vaccine dose gives the previously infected a dramatic boost in virus-fighting immune cells, more than people who have never been infected get from two shots.
Other recent studies published in Science and Nature show the combination of a prior infection and vaccination also broadens the strength of people’s immunity against a changing virus. It’s what virologist Shane Crotty of California’s La Jolla Institute for Immunology calls “hybrid immunity.”
Vaccinated survivors “can make antibodies that can recognize all kinds of variants even if you were never exposed to the variant,” Crotty said. “It’s pretty sweet.”
One warning for anyone thinking of skipping vaccination if they had a prior infection: The amount of natural immunity can vary from person to person, possibly depending on how sick they were to begin with. The Rush University study found four of 29 previously infected people had no detectable antibodies before they were vaccinated — and the vaccines worked for them just like they work for people who never had COVID-19.
Why do many of the previously infected have such a robust response to vaccination? It has to do with how the immune system develops multiple layers of protection.
After either vaccination or infection, the body develops antibodies that can fend off the coronavirus the next time it tries to invade. Those naturally wane over time. If an infection sneaks past them, T cells help prevent serious illness by killing virus-infected cells — and memory B cells jump into action to make lots of new antibodies.
Those memory B cells don’t just make copies of the original antibodies. In immune system boot camps called germinal centers, they also mutate antibody-producing genes to test out a range of those virus fighters, explained University of Pennsylvania immunologist John Wherry.
The result is essentially a library of antibody recipes that the body can choose from after future exposures — and that process is stronger when vaccination triggers the immune system’s original memory of fighting the actual virus.
With the delta variant’s super infectiousness, getting vaccinated despite a prior infection “is more important now than it was before to be sure,” Crotty said. “The breadth of your antibodies and potency against variants is going to be far better than what you have right now.”
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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education. The AP is solely responsible for all content.
Lauran Neergaard And Mike Stobbe, The Associated Press
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.
