Health
Why 'waning immunity' from COVID-19 vaccines isn't as bad as it sounds – CBC.ca
This is an excerpt from Second Opinion, a weekly roundup of health and medical science news emailed to subscribers every Saturday morning. If you haven’t subscribed yet, you can do that by clicking here.
Canadians concerned over waning immunity from COVID-19 vaccines, breakthrough infections and the need for booster shots in the general public could benefit from a dose of some important context, experts say.
Antibodies, your first line of defence against COVID-19 infection, do decline — and may even be doing so as you’re reading this — but that’s not unexpected.
While one aspect of your vaccine-induced immunity to COVID-19 is technically “waning” in the weeks and months after vaccination, that’s not necessarily a bad thing — because it’s not your immune system’s only form of protection against the virus.
“I don’t even like the term,” said University of Toronto immunologist Jennifer Gommerman. “And the reason I don’t like the term is that it implies that the immune response in its entirety is declining.”
It’s “entirely normal” for antibody levels to drop initially after vaccination and your immune response to the virus to become “contracted” over time, she said. But your body is also creating “highly efficient” memory B cells to fight off COVID-19 long term.
B cells work quickly to generate large quantities of antibodies in the weeks after vaccination, but they typically produce more effective antibodies as time goes on, helping sharpen the long-term response to a virus.
So while reports of waning immunity may sound concerning, that initial decrease in antibody levels may also be necessary in the fight against COVID-19, as it helps fine-tune the immune system’s plan of attack.
A new study published in the journal Science found “robust cellular immune memory” from B cells for at least six months after mRNA vaccination against all circulating strains of the virus — even the highly contagious delta variant.
The researchers found those memory cells, unlike the initial wave of antibodies, continue to learn how to fend off the virus months after vaccination and are actually getting better at it over time.
“That doesn’t sound like ‘waning’ to me,” Gommerman said. “There’s a natural contraction, but waning implies that something bad is happening.”
Breakthrough infections don’t tell the whole story
Reports of waning immunity and breakthrough infections have sporadically emerged across Canada in places like the Northwest Territories and New Brunswick, but lack important context and data on who is seriously affected and why.
The N.W.T. has been in the midst of a COVID-19 outbreak since mid-August that started in the Sahtu region before spreading to Yellowknife and its surrounding communities. It has infected 1,584 residents.
During that time, there have been 54 hospitalizations attributed to the outbreak, about 17 of which were among fully vaccinated people. A government spokesperson declined to comment on how many of the nine deaths in the territory were among those fully vaccinated.
WATCH | Concerns over waning immunity leads to expansion of boosters in N.W.T.:
In New Brunswick, where reports that one in five COVID-19 deaths occurred in people who were fully vaccinated made headlines this week, the data shows that while 17 fully vaccinated people have died, evidence of widespread waning immunity is lacking.
“New Brunswick has not identified confirmed evidence of waning immunity among COVID-19 cases,” a government spokesperson said in a statement.
In terms of national numbers, 94.7 per cent of all COVID-19 cases in Canada since Dec. 14 have been among those not fully vaccinated, as well as 95.8 per cent of hospitalizations and 94.3 per cent of deaths, according to the Public Health Agency of Canada (PHAC).
That means a total of 520 fully vaccinated Canadians have died of COVID-19 in the nearly 10 months since our vaccine rollout started, compared with 8,520 who were not considered fully vaccinated during that same time period.
“If we have 100 per cent or 95 per cent of the population vaccinated, almost all the cases that we see, including severe cases, will be in vaccinated people — just because most everyone’s vaccinated,” said Dr. Lynora Saxinger, an infectious diseases physician and associate professor at the University of Alberta.
“So that very rare outcome becomes the majority of the outcomes, and seeing an increasing number of cases in vaccinated people over time doesn’t actually mean that the vaccine works less well, necessarily.”
Underlying conditions key to breakthrough infections
PHAC says fully vaccinated Canadians who do get COVID-19 are also 79 per cent less likely to be hospitalized and 64 per cent less likely to die, backing up new Canadian data showing strong vaccine protection from infection, hospitalization and death.
But key information on the age, underlying health conditions or specific vaccine combination administered to those who were hospitalized or died from COVID-19 two weeks after their second shot is not available in Canada due to health privacy laws.
The recent death of former U.S. Secretary of State Colin Powell from COVID-19 sparked fresh debate about breakthrough infections and waning immunity. But less attention was paid to the fact he was at heightened risk due to a blood cancer called multiple myeloma.
Older, frailer Canadians living with comorbidities in congregate settings, such as long-term care facilities, are at increased risk of breakthrough infections because their antibody levels drop “much faster” than in the general population, said Gommerman.
A recent preprint study from the Toronto-based Lunenfeld-Tanenbaum Research Institute at Sinai Health analyzed 119 Ontario long-term care residents and 78 staff over four months, finding much lower levels of neutralizing antibodies in the elderly patients.
Gommerman also stresses there’s an important difference between infections and disease.
“We expect people to get infected — even healthy people to get infected — as antibody levels decline, because the only thing that can protect you against a breakthrough infection are antibodies,” she said.
“But we have to think about who we’re looking at, and what underlying comorbidities might be there in people who experienced breakthrough disease.”
Other immunocompromised groups, such as transplant patients, have shown declining protection from COVID-19 vaccines, as evidenced in the New England Journal of Medicine from researchers at the University Health Network (UHN) in Toronto.
WATCH | NACI recommends COVID-19 booster shots for long-term care residents:
“If you are a healthy person and you’ve been fully vaccinated, you don’t need to worry about getting severe COVID-19,” Gommerman said.
“If you are worried about getting infected with SARS-CoV-2, you should worry because you have people around you who are not vaccinated or who are under-immune.”
Boosters for general population ‘premature’ in Canada
New data from researchers at the Institute for Clinical Evaluative Sciences (ICES) in Toronto, which has not yet been peer-reviewed, found fully vaccinated people over 16 in Ontario were highly protected against both infection and severe COVID-19 after eight months.
ICES’s vaccine estimates, which have not yet been published, show that protection against symptomatic infection does drop — from 94 per cent to 81 per cent — but protection against severe outcomes remained high, at more than 90 per cent.
“The main takeaway is that we don’t need to do boosters at this time for the general population. We can hold off and wait and see — and when we start seeing the waning, then that’s when we should use the boosters,” said Dr. Jeff Kwong, an epidemiologist and senior scientist at ICES.
“It would be premature to do it at this time and not in our best interest, because we’re allowing other variants to emerge potentially if we let the pandemic spread uncontrolled in other parts of the world [where] they’re not vaccinated.”
WATCH | PHAC reviewing data supporting COVID booster shots in Canada:
Saxinger said the vast majority of Canadians who get severely ill or hospitalized after full vaccination are the very elderly, the immunocompromised, transplant patients and people with certain types of cancers.
“That group of people, of course, they should get a third dose,” she said. “But even with a third dose, they still are going to remain vulnerable as long as we have circulating virus in the community.”
Health
RCMP warn about benzodiazepine-laced fentanyl tied to overdose in Alberta – Edmonton Journal
Article content
Grande Prairie RCMP issued a warning Friday after it was revealed fentanyl linked to a deadly overdose was mixed with a chemical that doesn’t respond to naloxone treatment.
The drugs were initially seized on Feb. 28 after a fatal overdose, and this week, Health Canada reported back to Mounties that the fentanyl had been mixed with Bromazolam, which is a benzodiazepine.
Article content
Mounties say this is the first recorded instance of Bromazolam in Alberta. The drug has previously been linked to nine fatal overdoses in New Brunswick in 2022.
The pills seized in Alberta were oval-shaped and stamped with “20” and “SS,” though Mounties say it can come in other forms.
Naloxone treatment, given in many cases of opioid toxicity, is not effective in reversing the effects of Bromazalam, Mounties said, and therefore, any fentanyl mixed with the benzodiazepine “would see a reduced effectiveness of naloxone, requiring the use of additional doses and may still result in a fatality.”
From January to November of last year, there were 1,706 opioid-related deaths in Alberta, and 57 linked to benzodiazepine, up from 1,375 and 43, respectively, in 2022.
Mounties say officers responded to about 1,100 opioid-related calls for service, last year with a third of those proving fatal. RCMP officers also used naloxone 67 times while in the field, a jump of nearly a third over the previous year.
Recommended from Editorial
Share this article in your social network
Health
CFIA continues surveillance for HPAI in cattle, while sticking with original name for disease – RealAgriculture
The Canada Food Inspection Agency will continue to refer to highly pathogenic avian influenza in cattle as HPAI in cattle, and not refer to it as bovine influenza A virus (BIAV), as suggested by the American Association of Bovine Practitioners earlier this month.
Dr. Martin Appelt, senior director for the Canadian Food Inspection Agency, in the interview below, says at this time Canada will stick with “HPAI in cattle” when referencing the disease that’s been confirmed in dairy cattle in multiple states in the U.S.
The CFIA’s naming policy is consistent with the agency’s U.S. counterparts’, as the U.S. Animal and Plant Health Inspection Service has also said it will continue referring to it as HPAI or H5N1.
Appelt explains how the CFIA is learning from the U.S. experience to-date, and how it is working with veterinarians across Canada to stay vigilant for signs of the disease in dairy and beef cattle.
As of April 19, there has not been a confirmed case of HPAI in cattle in Canada. Appelt says it’s too soon to say if an eventual positive case will significantly restrict animal movement, as is the case with positive poultry cases.
This is a major concern for the cattle industry, as beef cattle especially move north and south across the U.S. border by the thousands. Appelt says that CFIA will address an infection in each species differently in conjunction with how the disease is spread and the threat to neighbouring farms or livestock.
Currently, provincial dairy organizations have advised producers to postpone any non-essential tours of dairy barns, as a precaution, in addition to other biosecurity measures to reduce the risk of cattle contracting HPAI.
Subscribe: Apple Podcasts | Spotify | RSS | All Podcasts
jQuery(document).ready(function($) {
$(“#homesub”).validate(
rules:
first_name:
required: true,
minlength: 2
,
last_name:
required: true,
minlength: 2
,
email:
required: true,
email: true,
minlength: 2
,
state:
required: true,
,
role:
required: true,
,
“listid[]”:
required: true,
minlength: 1
,
messages:
first_name: “Your first name is required.”,
last_name: “Your last name is required.”,
email: “Please verify your email is correct.”,
state: “Your state/province is required.”,
role: “Your role is required.”,
“listid[]”: “Select at least one list is required.”
,
submitHandler: function()
$.ajax(
type: “POST”,
url: “https://www.realagriculture.com/wp-admin/admin-ajax.php”,
data:
action: “realag_cc_process_subscribe_onclick”,
form: “homesub”,
data: $(“#homesub”).serialize(),
,
dataType: “html”,
timeout: 30000,
error: function(response)
console.log(response);
,
success: function(response)
$(“#homesub”).html(response);
,
);
);
});
Health
Toronto reports 2 more measles cases. Use our tool to check the spread in Canada – Toronto Star
/* OOVVUU Targeting */
const path = ‘/news/canada’;
const siteName = ‘thestar.com’;
let domain = ‘thestar.com’;
if (siteName === ‘thestar.com’)
domain = ‘thestar.com’;
else if (siteName === ‘niagarafallsreview.ca’)
domain = ‘niagara_falls_review’;
else if (siteName === ‘stcatharinesstandard.ca’)
domain = ‘st_catharines_standard’;
else if (siteName === ‘thepeterboroughexaminer.com’)
domain = ‘the_peterborough_examiner’;
else if (siteName === ‘therecord.com’)
domain = ‘the_record’;
else if (siteName === ‘thespec.com’)
domain = ‘the_spec’;
else if (siteName === ‘wellandtribune.ca’)
domain = ‘welland_tribune’;
else if (siteName === ‘bramptonguardian.com’)
domain = ‘brampton_guardian’;
else if (siteName === ‘caledonenterprise.com’)
domain = ‘caledon_enterprise’;
else if (siteName === ‘cambridgetimes.ca’)
domain = ‘cambridge_times’;
else if (siteName === ‘durhamregion.com’)
domain = ‘durham_region’;
else if (siteName === ‘guelphmercury.com’)
domain = ‘guelph_mercury’;
else if (siteName === ‘insidehalton.com’)
domain = ‘inside_halton’;
else if (siteName === ‘insideottawavalley.com’)
domain = ‘inside_ottawa_valley’;
else if (siteName === ‘mississauga.com’)
domain = ‘mississauga’;
else if (siteName === ‘muskokaregion.com’)
domain = ‘muskoka_region’;
else if (siteName === ‘newhamburgindependent.ca’)
domain = ‘new_hamburg_independent’;
else if (siteName === ‘niagarathisweek.com’)
domain = ‘niagara_this_week’;
else if (siteName === ‘northbaynipissing.com’)
domain = ‘north_bay_nipissing’;
else if (siteName === ‘northumberlandnews.com’)
domain = ‘northumberland_news’;
else if (siteName === ‘orangeville.com’)
domain = ‘orangeville’;
else if (siteName === ‘ourwindsor.ca’)
domain = ‘our_windsor’;
else if (siteName === ‘parrysound.com’)
domain = ‘parrysound’;
else if (siteName === ‘simcoe.com’)
domain = ‘simcoe’;
else if (siteName === ‘theifp.ca’)
domain = ‘the_ifp’;
else if (siteName === ‘waterloochronicle.ca’)
domain = ‘waterloo_chronicle’;
else if (siteName === ‘yorkregion.com’)
domain = ‘york_region’;
let sectionTag = ”;
try
if (domain === ‘thestar.com’ && path.indexOf(‘wires/’) = 0)
sectionTag = ‘/business’;
else if (path.indexOf(‘/autos’) >= 0)
sectionTag = ‘/autos’;
else if (path.indexOf(‘/entertainment’) >= 0)
sectionTag = ‘/entertainment’;
else if (path.indexOf(‘/life’) >= 0)
sectionTag = ‘/life’;
else if (path.indexOf(‘/news’) >= 0)
sectionTag = ‘/news’;
else if (path.indexOf(‘/politics’) >= 0)
sectionTag = ‘/politics’;
else if (path.indexOf(‘/sports’) >= 0)
sectionTag = ‘/sports’;
else if (path.indexOf(‘/opinion’) >= 0)
sectionTag = ‘/opinion’;
} catch (ex)
const descriptionUrl = ‘window.location.href’;
const vid = ‘mediainfo.reference_id’;
const cmsId = ‘2665777’;
let url = `https://pubads.g.doubleclick.net/gampad/ads?iu=/58580620/$domain/video/oovvuu$sectionTag&description_url=$descriptionUrl&vid=$vid&cmsid=$cmsId&tfcd=0&npa=0&sz=640×480&ad_rule=0&gdfp_req=1&output=vast&unviewed_position_start=1&env=vp&impl=s&correlator=`;
url = url.split(‘ ‘).join(”);
window.oovvuuReplacementAdServerURL = url;
Canada has seen a concerning rise in measles cases in the first months of 2024.
By the third week of March, the country had already recorded more than three times the number of cases as all of last year. Canada had just 12 cases of measles in 2023, up from three in 2022.
function buildUserSwitchAccountsForm()
var form = document.getElementById(‘user-local-logout-form-switch-accounts’);
if (form) return;
// build form with javascript since having a form element here breaks the payment modal.
var switchForm = document.createElement(‘form’);
switchForm.setAttribute(‘id’,’user-local-logout-form-switch-accounts’);
switchForm.setAttribute(‘method’,’post’);
switchForm.setAttribute(‘action’,’https://www.thestar.com/tncms/auth/logout/?return=https://www.thestar.com/users/login/?referer_url=https%3A%2F%2Fwww.thestar.com%2Fnews%2Fcanada%2Ftoronto-reports-2-more-measles-cases-use-our-tool-to-check-the-spread-in-canada%2Farticle_20aa7df4-e88f-11ee-8fad-8f8368d7ff53.html’);
switchForm.setAttribute(‘style’,’display:none;’);
var refUrl = document.createElement(‘input’); //input element, text
refUrl.setAttribute(‘type’,’hidden’);
refUrl.setAttribute(‘name’,’referer_url’);
refUrl.setAttribute(‘value’,’https://www.thestar.com/news/canada/toronto-reports-2-more-measles-cases-use-our-tool-to-check-the-spread-in-canada/article_20aa7df4-e88f-11ee-8fad-8f8368d7ff53.html’);
var submit = document.createElement(‘input’);
submit.setAttribute(‘type’,’submit’);
submit.setAttribute(‘name’,’logout’);
submit.setAttribute(‘value’,’Logout’);
switchForm.appendChild(refUrl);
switchForm.appendChild(submit);
document.getElementsByTagName(‘body’)[0].appendChild(switchForm);
function handleUserSwitchAccounts()
window.sessionStorage.removeItem(‘bd-viafoura-oidc’); // clear viafoura JWT token
// logout user before sending them to login page via return url
document.getElementById(‘user-local-logout-form-switch-accounts’).submit();
return false;
buildUserSwitchAccountsForm();
#ont-map-iframepadding:0;width:100%;border:0;overflow:hidden;
#ontario-cases-iframepadding:0;width:100%;border:0;overflow:hidden;
#province-table-iframepadding:0;width:100%;border:0;overflow:hidden;
console.log(‘=====> bRemoveLastParagraph: ‘,0);
-
Media16 hours ago
DJT Stock Rises. Trump Media CEO Alleges Potential Market Manipulation. – Barron's
-
Media18 hours ago
Trump Media alerts Nasdaq to potential market manipulation from 'naked' short selling of DJT stock – CNBC
-
Investment17 hours ago
Private equity gears up for potential National Football League investments – Financial Times
-
Sports22 hours ago
2024 Stanley Cup Playoffs 1st-round schedule – NHL.com
-
News15 hours ago
Canada Child Benefit payment on Friday | CTV News – CTV News Toronto
-
Real eState9 hours ago
Botched home sale costs Winnipeg man his right to sell real estate in Manitoba – CBC.ca
-
Business17 hours ago
Gas prices see 'largest single-day jump since early 2022': En-Pro International – Yahoo Canada Finance
-
Art20 hours ago
Enter the uncanny valley: New exhibition mixes AI and art photography – Euronews