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Omicron scrambles what we know about immunity. Now what? – Mint

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Scientists are already scrambling to learn how well our existing vaccines will work against this new coronavirus variant. That can help predict how much benefit might come from speeding up worldwide vaccination and booster campaigns, and whether vaccine passports will protect people or give a false sense of reassurance.  Reports that most omicron cases are mild are understandably reassuring for many individuals — especially those of us who aren’t elderly or immunocompromised and have access to booster shots. But some scientists have frowned on such optimism because of the larger picture. If this thing keeps growing exponentially and infects millions of people in a short time, health systems will collapse, even if a tinier fraction of cases are serious. Cases are rising rapidly in the U.K. and South Africa, suggesting that omicron has some advantage over delta, the currently dominant coronavirus variant. It might be that it’s inherently more transmissible, or that it’s better able to get past immunity in those who’ve been infected or vaccinated, or some combination of those factors. Omicron’s genes are weirdly different from previous variants, appearing to be only distantly related to delta. No one is sure where it came from — possibly from growing for months in immune-compromised patients, or from leaping into an animal host and back into humans.

It has 21 mutations in the top part of the spike protein, molecular epidemiologist Emma Hodcroft of the University of Bern said in an interview.(3) Some of these mutations are alarming because they’d been observed in earlier variants that were good at evading immunity from vaccines or past infections.

In just a couple of weeks, scientists have accumulated an impressive amount of preliminary data. Some labs assembled mock versions of omicron by genetically manipulating other variants to carry some of the variant’s key mutations, Hodcroft said. Researchers can grow these “pseudo viruses” in petri dishes and test how well they stand up to antibodies extracted from the blood of vaccinated or previously infected people.

Then last week, a lab in South Africa made headlines with results on the behavior of actual samples of omicron. It found the virus did somewhat evade immunity generated by two shots of the Pfizer vaccine, but was neutralized well by antibodies taken from patients who had been both vaccinated and previously infected with earlier variants. At around the same time, Pfizer announced that antibodies from a booster shot helped stop omicron in laboratory experiments, though the findings aren’t peer reviewed, and outside researchers didn’t get to see the data.

At a press briefing Wednesday, Harvard infectious disease specialist Yonatan Grad said they still don’t know details of any of these experiments. Did the blood come from people who were vaccinated last month or 10 months ago? This matters because other studies demonstrated that antibodies from the Pfizer and Moderna vaccines wane significantly over six to nine months.

“In real humans, it might be more complex, but I think we can probably say that we expect more reinfection or breakthrough infections with omicron than we’ve seen with other variants,” Hodcroft said. 

How severe those infections will be isn’t clear. Vaccines (or past infection) leave people with immune cells that hide in the bone marrow and lymph nodes, and these become activated if there’s a new infection and create a bunch of new antibodies. Lab experiments wouldn’t necessarily capture this phenomenon.

With only partial knowledge about the dangers of omicron, wealthy countries such as the U.S. are starting to push harder to get third doses into everyone, though we’d save more lives by getting initial doses to countries with low supplies. Scientists will know a lot more in three or four weeks, when cases of severe disease would be expected to crop up, after omicron has spread and cases have had time to progress, and epidemiologists can measure how fast the variant is expanding outside South Africa.

How and where the disease spreads will depend on past cases in the population, vaccine uptake, seasonal cycles and other factors nobody yet understands. The past behavior has been surprising.

Earlier variants, including alpha, rose fast in the eastern U.S. in the fall of 2020 and then plummeted in the middle of the winter 2021. Those early variants barely touched India, but delta suddenly exploded there in the spring of 2021. That wave, too, crested and fell suddenly.

With omicron, the severity of disease is going to be particularly hard to ascertain without waiting until it infects a sizable number of people of different ages. The original version of SARS-CoV-2 was mild in most people — and it was enormously destructive.

“Even if Omicron has a milder severity — and we don’t know this at the moment — if it spreads really quickly, even a smaller percent of a big number is a big number,” Hodcroft said. “We’re also, in most of the West, fairly ill-prepared for this, since our delta cases are riding so high — we have very little wiggle room left.” 

So the best-case scenario would be either that omicron isn’t as transmissible as it first appeared and it fizzles out, or that it’s only little more transmissible than delta and a lot milder — so mild that almost nobody has to be admitted to an ICU.

“It would be the best thing we can hope for,” Hodcroft said, but it’s not something she or other experts are betting on.

Hope is fine as long as it doesn’t lull people into inaction or lessen the sense of urgency. A lot can be done now, including producing omicron-specific vaccines and doing a better job of distributing existing vaccines to the countries that need them most. People need to be ready for more restrictions if the worst-case scenarios play out.

There’s some evidence that vaccinations cut back on transmission. That means the more shots we can get into arms around the world, the fewer chances the virus has to stumble on some new variant — perhaps something that’s not mild at all.

This story has been published from a wire agency feed without modifications to the text.

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Omicron-specific vaccine likely to come too late to help in this wave: Sharma – Victoria News

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Health Canada’s chief medical adviser says variant-specific vaccines can be approved faster than the general ones first issued to combat COVID-19, but one targeting the Omicron strain still likely won’t be ready in time to help with the latest wave.

Dr. Supriya Sharma said what is really needed are vaccines that can possibly stop more than one variant at a time, including those yet to come.

Omicron became the dominant variant in Canada in just over two weeks, and the Public Health Agency of Canada said Friday it’s now believed to be responsible for more than 90 per cent of all COVID-19 cases.

Studies suggest two doses of the existing mRNA vaccines from Pfizer-BioNTech and Moderna are not good at preventing infection from Omicron.

Multiple studies, however, suggest the vaccines are excellent at keeping symptoms mild, preventing hospitalizations, and shortening the stay and lowering the level of care for those who do get admitted to hospital. Fewer vaccinated Omicron patients, for example, need mechanical ventilation.

Both Pfizer and Moderna are working on new versions of their vaccines that specifically target the Omicron variant.

Moderna is hoping to get its product into trials early this year. Pfizer said it could have 100 million doses of theirs ready as early as March, and Canada has contracts for boosters from both companies that would include vaccines for variants too.

But Sharma said even with the expedited review process for vaccine variants, that’s “probably not” fast enough.

“By that time, based on what we’ve known about the Omicron wave, it might well and truly be through,” she said. “And then the question is always, ‘is there another variant that’s coming up?’”

The solution, she said, likely lies with vaccines that can target more than one variant at a time.

READ MORE: Omicron may seem unavoidable, but experts say ‘let it rip’ isn’t the solution

The COVID-19 vaccine technical committee of the World Health Organization said the same thing on Jan. 11, noting Omicron is the fifth variant of concern in two years and “is unlikely to be the last.”

Booster shots that heighten antibody development became the immediate response to Omicron for many governments, including Canada.

Dr. Srinivas Murthy, a British Columbia pediatrician and co-chair of the WHO’s clinical research committee on COVID-19, told The Canadian Press that boosters aren’t a long-term viable option.

“Boosting your way out of a pandemic is going to inevitably shoot you in the foot in the sense that you’re going to have a future variant that’s going to emerge that’s going to cause problems,” he said. “It’s going to evade your vaccines, and then you’re going to have to scramble.”

Omicron doesn’t evade the existing vaccines entirely but a future variant could, he said. The issue largely stems from the fact that the original vaccines train the body’s immune system to recognize what is called the spike protein found on the surface of a virus, and that spike protein is mutating significantly.

Think of the mutated spike protein as a bit of a disguise that makes it harder for the immune system to recognize the virus and mount a defence to kill it off.

Omicron has more than 50 mutations, and at least 36 are on the spike protein.

Multivalent vaccines that use the spike protein from more than one variant, or that target the genetic components of a virus rather than the spike protein, are possibly the ones that could offer protection for both this pandemic and the next novel coronavirus that emerges.

“It’s pan-coronavirus, where it’s looking at big broad neutralizing responses and you don’t have to update it every season and so on,” said Murthy. “That’s been the Holy Grail of flu vaccinology for the past number of decades. We haven’t achieved that yet, because flu is a bit tricky, but we think that it’s achievable for coronavirus, specifically.”

The United States Army has a version heading into Phase 2 trials that can attach multiple spike proteins. A vaccine with the specific spike proteins from all five COVID-19 variants of concern would likely be more successful, even against future variants, because they all share some of the same mutations and what one might miss another may catch.

Moderna is working on trials for multivalent vaccines using combinations of the spike proteins from the original virus and one of the variants, or two of the variants together. It’s not clear when they would be ready for use.

Sharma said even if the vaccines aren’t working as well against variants as they were against the original virus, to her “they’re still miraculous.”

“To have a vaccine that was developed that quickly, that still has, through multiple variants … with boosters, up to 70, 80 per cent effectiveness against serious disease, ailments, hospitalization and death,” she said. “That is miraculous for a new vaccine for a new virus.”

Mia Rabson, The Canadian Press


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Canada approves Pfizer’s oral COVID-19 antiviral treatment, seeks supplies

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Canada on Monday approved Pfizer Inc’s oral antiviral treatment for mild to moderate cases of COVID-19 in people aged 18 and older but said supply shortages would keep doses from being made available immediately.

Infections and hospitalizations due the Omicron variant have been rising in Canada, forcing provinces to put in restrictions and the federal government to support impacted businesses.

“(This) is particularly important, as access to easy to use treatments could help to reduce the severity of COVID-19 in adults who become newly infected at high risk of progressing to serious illness,” said chief public health officer Theresa Tam.

Pfizer’s two-drug antiviral regimen, Paxlovid, was nearly 90% effective in preventing hospitalizations and deaths in patients at high risk of severe illness, according to data from the company’s clinical trial.

It is meant to be taken at home for five days beginning shortly after onset of symptoms.

Ottawa said last month it had signed a deal with Pfizer for a million treatment courses, pending approval. But getting those supplies could face hurdles.

“While there is currently limited global supply of Paxlovid, we are working to firm up a delivery schedule with the intent of bringing treatment courses to Canada as quickly as possible,” Tam told a briefing.

Ontario, the most populous of the 10 provinces, is seeing signs that Omicron cases may have peaked, said chief medical officer Kieran Moore.

“I’m starting to have much more hope … the number of cases is decelerating instead of accelerating in terms of hospitalizations and (people admitted to) intensive care units,” he told an Ottawa radio station.

Official data show that as of Jan 8, 87.8% of Canadians aged 12 and above had received two doses of a COVID-19 vaccine.

The U.S. authorized the Pfizer treatment for people ages 12 and older last month.

Canada is still looking at whether to approve Merck & Co’s oral antiviral pill, molnupiravir, which had less impressive results than Paxlovid in its pivotal clinical trial.

(Reporting by David Ljunggren in Ottawa and Ismail Shakil in Bengaluru; Editing by Franklin Paul and Bill Berkrot)

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January 16, 2022 coronavirus update for Oakville – Oakville News

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This is Oakville’s coronavirus update for Sunday, Jan. 16, 2022. As children head back to school tomorrow, the main takeaway from today’s COVID-19 update is the increase in the number of outbreaks in long-term care, retirement, and hospital facilities. OTMH is now dealing with two outbreaks as a new one was declared at 5 South, and the province has 231 hospitals recording ongoing outbreaks, an increase nice.

Hospital status

A new outbreak at OTMH was declared but not shown on the region’s update of Friday, Jan. 14, 2022. Halton does not provide new information on weekends or holidays. 

  • Oakville – 70 patients – plus 6
  • Halton – 126 patients – plus 10
  • Ontario – 3,595 patients – minus 362 (ICU 563 plus 19, Ventilators 327 plus 19)

Outbreaks

There are currently nine active outbreaks with 58 cases (LTC-41, retirement homes-13, hospitals-2) in Oakville. 

Ontario

Long-term care facilities status

  • 424 ongoing outbreaks -plus 9
  • 27,391 cases – plus 320
  • 39,06 resident deaths – plus 9

Retirement homes

  • 319 ongoing outbreaks – plus 16

Hospitals

  • 231 ongoing outbreaks – plus 16

Vaccination status

Halton 

  • 1st Dose (5+) – 90%
  • 2nd Dose (5+) – 83%
  • Boosters (18+) – 48%

Ontario administered 117,300 vaccinations

  • 1st Dose (5+) – 82%
  • 2nd Dose (5+) – 3%

Case status

The number of confirmed new cases in Oakville, Halton and Ontario is under-reported since the province restricted access to testing, limiting it to high-risk individuals, healthcare providers, and patients. 

Halton

  • 36,184 cases – plus 552 or 5,962.2 cases per million
  • 634.6 new weekly cases per 100,000, down 15.9 per cent from 2 weeks ago

Ontario

  • 948,086 total cases – plus 10,450 or 6,434.7 cases per million
  • 503.1 new weekly cases per 100,000, down 22.4 per cent from 2 weeks ago
  • 843,073 recoveries –  plus 15,317
  • 10,605 deaths – plus 40
  • 94,408 active cases – minus 4,907

**Vaccine booking: Halton continues to book first and second-dose vaccinations for all residents age five and older, plus third-dose boosters for all adults age 18 and up.

Parents must make booster doses and appointments for children in advance, but first and second doses for those 12 and up are available on a walk-in basis.

All vaccines approved for use in Canada effectively protect you against COVID-19 and all known variants of concern.

CLICK HERE to book a first, second or third vaccination appointment at a Halton Region vaccine clinic

The evidence is clear: vaccination is the best way to be protected. Local, provincial, national and international health units all affirm the same data that Canada’s approved vaccines effectively protect you from COVID-19 and significantly reduce your risks of getting sick, going to the hospital, and dying from the disease.

Pictured right is a graph from the Halton region showing how dramatically your risk of getting sick or being admitted to hospital is when vaccinated.

Sources: 

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