Connect with us

Health

COVID-19: Research raises questions over delayed second vaccine doses for seniors – BayToday

Published

 on


TORONTO — More questions are being raised about how long second shots of the COVID-19 vaccine can be delayed for seniors and other immunocompromised people.

The federal body that advises how vaccines be deployed said Thursday it’s reviewing a Vancouver study that found long-term care residents had a weaker immune response to their first dose than healthy adults. 

After supplies slowed to a trickle earlier this year, the National Advisory Committee on Immunization said provinces and territories can delay second doses by as long as four months. 

That’s instead of recommended schedule of spacing out the two-dose Pfizer-BioNTech and Moderna vaccines by three to four weeks, and the AstraZeneca product by four to 12 weeks.

Committee chair Dr. Caroline Quach said Thursday that NACI is looking at the Vancouver research, which found a weaker antibody response among older recipients but did not measure whether seniors were more likely to fall sick or die.

She said the findings will be assessed along with data from Quebec and the United Kingdom.

“What is so difficult with this disease is that there is no correlate of protection. That means that the presence and quantity of antibody present does not mean protection, or lack thereof,” Quach said in an email to The Canadian Press.

“Based on all those data, NACI will see if exceptions to the extended interval are necessary, keeping in mind that we are managing risk at a population level: the more people are vaccinated, the more likely we are to stop transmission, which will also be protective for the most vulnerable who may not mount an optimal response.”

The Vancouver data, funded by the COVID-19 Immunity Task Force, has yet to be peer-reviewed but adds to concerns about the rollout strategy of provinces including Ontario, Manitoba, Saskatchewan, Alberta, and British Columbia.

Task force director Dr. Tim Evans said the findings underscore a need to monitor senior recipients very carefully after their first shot.

“The immune response is so complicated and we still don’t fully understand what are called the correlates of protection,” Evans said from Montreal, where he is director and associate dean of the school of population and global health at McGill University.

“The most important takeaway from this study is we have to be very vigilant in monitoring the followup for the elderly, or immunocompromised with respect to extending the vaccine dose beyond what’s recommended.”

Evans stressed that older people in both long-term care and the community are well-protected for many weeks by a single dose of an mRNA vaccine, but said there may be limits to how long some people should wait for their second dose.

He said COVID-19 vaccines have already been associated with dropping hospitalizations and deaths in Canada, but expected NACI may have to refine its advice for how they be used in various populations.

“We’ve got multiple vaccines, they all work a little bit differently and so we know that we don’t have a one-size-fits-all approach,” he said, adding that long-term care residents may be more vulnerable than seniors in the community.

“We’re going to have to get used to working with different approaches for different age groups with different vaccines over the coming months as the vaccine rollout continues.”

Earlier Thursday, Health Canada’s chief medical adviser Dr. Supriya Sharma noted her agency – a separate body from NACI – approved the vaccines for use according to their respective labels.

She also said NACI’s advice will evolve as new science becomes available.

“I think it does make sense that we potentially have a more nuanced recommendation around that delayed second dose, but those conversations are ongoing,” Sharma said.

This report by The Canadian Press was first published March 25, 2021.

Cassandra Szklarski, The Canadian Press

Let’s block ads! (Why?)



Source link

Continue Reading

Health

Today's coronavirus news: Ontario reporting 192 cases of COVID-19, one death; Mostly spectator-free opening ceremony kicks off Tokyo Games – Orangeville Banner

Published

 on


Orangeville.com

Adblock test (Why?)



Source link

Continue Reading

Health

Why are Covid cases rising among double vaccinated? – Deccan Herald

Published

 on


By Jamie Hartmann-Boyce for The Conversation,

Sir Patrick Vallance, the UK’s chief scientific adviser, has announced that 40 per cent of people admitted to hospital with Covid in the UK have had two doses of a coronavirus vaccine.

At first glance, this rings very serious alarm bells, but it shouldn’t. The vaccines are still working very well.

There are several factors at play that explain why such a high proportion of cases are in the fully vaccinated.

Covid vaccines are extremely effective, but none 100 per cent so. This itself isn’t surprising – flu vaccines aren’t 100 per cent effective either.

Yet in the US alone flu vaccines are estimated to prevent millions of cases of illness, tens of thousands of hospitalisations and thousands of deaths every year. The Covid vaccines are doing the same in the UK right now – all one has to do is compare the curves from the winter wave with those from this summer.

As cases are rising, hospitalisations and deaths are rising too, but not at anywhere near the same level as they were in the winter. In the second half of December 2020 – a time when UK case rates were similar to what they are now – about 3,800 people were being admitted to hospital with Covid each day.

The average now is around 700. So though that’s still higher than we wish it was, it’s a lot lower than it was the last time we had this many infections.

Covid is also growing among the vaccinated because the number of people in the UK who have had both doses is continuing to rise. At the time of writing, 88 per cent of UK adults have had a first dose and 69 per cent a second. As more and more of the population is vaccinated, the relative proportion of those with Covid who have had both jabs will rise.

If you imagine a hypothetical scenario in which 100 per cent of the population is double vaccinated, then 100 per cent of people with Covid, and in hospital with Covid, will also have had both jabs. As with deaths, this doesn’t mean the vaccine isn’t working. It just means the vaccine rollout is going very well.

Also read: WHO warns of ‘long term’ Covid impact on mental health

We also need to remember that the vaccine rollout in the UK has systematically targeted people at the highest risk from Covid.

Older people and people with health conditions that make them more vulnerable were the first to get vaccinated. Once vaccinated, these people (including me) are at much lower risk from Covid than they would have been otherwise – but they are still at risk.

That means that when we compare people with both vaccinations being hospitalised to those who haven’t had both doses, we aren’t comparing like with like. People with both vaccinations are more likely to have been at greater risk from Covid in the first place. This makes them both more likely to be hospitalised and more likely to have already received both of their vaccine doses.

Is Covid different in the vaccinated?

The latest data from Public Health England suggests that against the delta variant, which is now dominant in UK, two doses of any of the vaccines available in Britain are estimated to offer 79 per cent protection against symptomatic Covid and 96 per cent protection against hospitalisation.

We don’t have clear estimates yet from Public Health England on the level of protection against death caused by the delta variant – fortunately, this is partly driven by the fact deaths have been relatively low during this third wave in the UK.

But for the alpha variant, Public Health England data estimates the Pfizer vaccine to be between 95 per cent and 99 per cent effective at preventing death from Covid-19, with the AstraZeneca vaccine estimated to be between 75 per cent and 99 per cent effective. The evidence we have so far doesn’t suggest that the delta variant substantially changes this picture.

There’s lots we still need to learn about how people with both vaccine doses respond to getting infected with the virus. The UK’s Covid Symptom Study is looking at this.

One of the key questions that remain is who is at most risk. Emerging data – released in a preprint, so yet to be reviewed by other scientists – suggests people who are overweight or obese, poorer people, and people with health conditions causing frailty seem to be more likely to get infected after having both jabs.

The preprint also suggests that age itself doesn’t seem to affect chances of developing Covid after being vaccinated, nor does having a long-term condition such as asthma, diabetes or heart disease – but we need more data on this to be sure of these findings.

Generally, the Covid Symptom Study has found that people report the same Covid symptoms whether or not they’ve been vaccinated, but that people who’ve been vaccinated have fewer symptoms over a shorter period of time, suggesting less serious illness. The most commonly reported symptoms in people who had had both doses were headache, runny nose, sneezing, sore throat and loss of smell. 

(The author is a Senior Research Fellow, Departmental Lecturer and Director of Evidence-Based Healthcare DPhil Programme, Centre for Evidence-Based Medicine, University of Oxford)

Adblock test (Why?)



Source link

Continue Reading

Health

Canada’s and Zimbabwe’s paths for COVID-19 vaccination are worlds apart – The Globe and Mail

Published

 on


A forklift carries a pallet of the Sinopharm COVID-19 vaccine from China upon its arrival at Robert Mugabe International airport in Harare.

Tsvangirayi Mukwazhi/The Associated Press

When mother-of-three Amanda Wood heard that hundreds of coronavirus shots were available for teens, only one thing prevented her from racing to the vaccination site at a Toronto high school – her 13-year-old daughter’s fear of needles.

Wood told Lola: If you get the vaccine you’ll be able to see your friends again. You’ll be able to play sports. And enticed by the promise of resuming a normal, teen life, Lola agreed.

In Zimbabwe, more than 8,000 miles (13,000 kilometers) and a world away from Canada, immunity is harder to obtain.

On a recent day, Andrew Ngwenya sat outside his home in a working-class township in Harare, the capital, pondering how he could save himself and his family from COVID-19.

Ngwenya and his wife De-egma had gone to a hospital that sometimes had spare doses. Hours later, fewer than 30 people had been inoculated. The Ngwenyas, parents of four children, were sent home, still desperate for immunization.

“We are willing to have it but we can’t access it,” he said. “We need it, where can we get it?”

The stories of the Wood and Ngwenya families reflect a world starkly divided between vaccine haves and have nots, between those who can imagine a world beyond the pandemic and those who can only foresee months and perhaps years of illness and death.

In one country, early stumbles in the fight against COVID-19 were overcome thanks to money and a strong public health infrastructure. In the other, poor planning, a lack of resources and the failure of a global mechanism intended to share scarce vaccines have led to a desperate shortage of COVID-19 shots – and oxygen tanks and protective equipment, as well.

With 70% of its adult population receiving at least one dose of a COVID-19 vaccine, Canada has among the world’s highest vaccination rate and is now moving on to immunize children, who are at far lower risk of coronavirus complications and death.

Meanwhile, only about 9% of the population in Zimbabwe has received one dose of coronavirus vaccine amid a surge of the easier-to-spread delta variant, first seen in India. Many millions of people vulnerable to COVID-19, including the elderly and those with underlying medical problems, are struggling to get immunized as government officials introduce more restrictive measures.

Ngwenya said the crush of people trying to get vaccinated is disheartening.

“The queue is like 5 kilometers (about 3 miles) long. Even if you are interested in a jab you can’t stand that. Once you see the queue you won’t try again,” he said

Vaccines weren’t always plentiful in Canada. With no domestic coronavirus vaccine production, the country got off to a sluggish start, with immunization rates behind those in Hungary, Greece and Chile. Canada was also the only G7 country to secure vaccines in the first round of deliveries by a U.N.-backed effort set up to distribute COVID-19 doses primarily to poor countries known as COVAX.

Prime Minister Justin Trudeau said it had always been Canada’s intention to secure vaccines through COVAX, after investing more than $400 million in the project. The vaccines alliance, Gavi, said COVAX was also meant to provide rich countries with an “insurance policy” in case they didn’t have enough shots.

COVAX’s latest shipment to Canada – about 655,000 AstraZeneca vaccines – arrived in May, shortly after about 60 poor countries were left in the lurch when the initiative’s supplies slowed to a trickle. Bangladesh, for example, had been awaiting a COVAX delivery of about 130,000 vaccines for its Rohingya refugee population; the shots never arrived after the Indian supplier ceased exports.

Canada’s decision to secure vaccines through the U.N.-backed effort was “morally reprehensible,” said Dr. Prabhat Jha, chair of global health and epidemiology at the University of Toronto. He said Canada’s early response to COVID-19 badly misjudged the need for control measures including aggressive contact tracing and border restrictions.

“If not for Canada’s purchasing power to procure vaccines, we would be in bad shape right now,” he said.

Weeks after the COVAX vaccines arrived, more than 33,000 doses were still sitting in warehouses in Ottawa after health officials recommended Canadians get shots made by Pfizer-BioNTech or Moderna instead – of which they had bought tens of millions of doses.

The Wood children got the Pfizer vaccine. When Canada began immunizing children aged 12 and over, Wood, who works with children in the entertainment industry and her architect husband didn’t hesitate.

Wood said her children, who are all avid athletes, have been unable to play much hockey, soccer or rugby during repeated lockdowns. Lola has missed baking lemon loaves and chocolate chip cookies with her grandmother, who lives three blocks away.

“We felt we had to do our part to keep everyone safe, to keep the elderly safe, and to get the economy going again and the kids back to school,” she said.

In Zimbabwe, there is no expectation of a return to normal anytime soon, and things are likely to get worse – Ngwenya worries about government threats to bar the unvaccinated from public services, including transport.

Although Zimbabwe was allocated nearly 1 million coronavirus vaccines through COVAX, none have been delivered. Its mix of purchased and donated shots – 4.2 million – consist of Chinese, Russian and Indian vaccines.

Official figures show that 4% of the country’s 15 million population are now fully immunized.

The figures make Zimbabwe a relative success in Africa, where fewer than 2% of the continent’s 1. 3 billion people have been vaccinated, according to the World Health Organization. Meanwhile, the virus is spreading to rural areas where the majority live and health facilities are shambolic.

Ngwenya is a part-time pastor with a Pentecostal church; he said he and his flock have had to rely on their faith to fight the coronavirus. But he said people would rather have vaccines first, and then prayer.

“Every man is scared of death,” he said. “People are dying and we can see people dying. This is real.”

Our Morning Update and Evening Update newsletters are written by Globe editors, giving you a concise summary of the day’s most important headlines. Sign up today.

Adblock test (Why?)



Source link

Continue Reading

Trending