Connect with us

Health

Omicron variant multiplies 70 times faster in airways than Delta: study – Global News

Published

 on


Major differences in how efficiently Omicron and other variants of the coronavirus multiply may help predict Omicron’s effects, researchers said on Wednesday.

Compared to the earlier Delta variant, Omicron multiplies itself 70 times more quickly in tissues that line airway passages, which may facilitate person-to-person spread, they said. But in lung tissues, Omicron replicates 10 times more slowly than the original version of the coronavirus, which might contribute to less-severe illness.

A formal report of the findings is under peer review for publication and has not been released by the research team. In a news release issued by Hong Kong University, study leader Dr. Michael Chan Chi-wai said, “It is important to note that the severity of disease in humans is not determined only by virus replication” but also by each person’s immune response to the infection, which sometimes evolves into life-threatening inflammation.

Chan added, “By infecting many more people, a very infectious virus may cause more severe disease and death even though the virus itself may be less pathogenic. Therefore, taken together with our recent studies showing that the Omicron variant can partially escape immunity from vaccines and past infection, the overall threat from Omicron variant is likely to be very significant.”

Omicron grips cells more tightly, withstands some antibodies

A structural model of how the Omicron variant attaches to cells and antibodies sheds light on its behavior and will help in designing neutralizing antibodies, according to researchers.

Using computer models of the spike protein on Omicron’s surface, they analyzed molecular interactions occurring when the spike grabs onto a cell-surface protein called ACE2, the virus’s gateway into the cell.

Read more:

Omicron variant might make COVID-19 vaccines less effective, WHO warns

Metaphorically, the original virus had a handshake with ACE2, but Omicron’s grip “looks more like a couple holding hands with their fingers entwined,” said Joseph Lubin of Rutgers University in New Jersey. The “molecular anatomy” of the grip may assist in explaining how Omicron’s mutations cooperate to help it infect cells, Lubin added.

The research team also modeled the spike with different classes of antibodies trying to attack it. The antibodies attack from different angles, “like a football team’s defense might tackle a ball carrier,” with one person grabbing from behind, another from the front, Lubin said. Some antibodies “appear likely to get shaken off” while others are likely to remain effective. Booster vaccines raise antibody levels, resulting in “more defenders,” which might compensate to some extent for “a weaker grip of an individual antibody,” Lubin said.


Click to play video: 'COVID-19: WHO warns of dismissing the Omicron variant as being ‘mild’, calls for stronger measures'



1:17
COVID-19: WHO warns of dismissing the Omicron variant as being ‘mild’, calls for stronger measures


COVID-19: WHO warns of dismissing the Omicron variant as being ‘mild’, calls for stronger measures

The findings, posted on Monday on the website bioRxiv ahead of peer review, need to be verified, “particularly with real-world samples from people,” Lubin said. “While our molecular structure predictions are by no means a final word on Omicron, (we hope) they enable a faster and more effective response from the global community.”

Four in 10 infected people may unknowingly spread virus

Infected people who show no symptoms might be contributing significantly to transmission of SARS-CoV-2, the virus that causes COVID-19, given that they account for 40.5% of confirmed infections worldwide, according to a study published online Tuesday in the journal JAMA Network Open.

Read more:

Omicron is raging in the U.K. What can Canada learn?

The researchers pooled data from 77 earlier studies involving a total of 19,884 individuals with confirmed SARS-CoV-2 infections. They found that among infected people in the general community, about 40% were asymptomatic, as were 54% of infected pregnant women, 53% of infected air or cruise travelers, 48% of infected nursing home residents or staff and 30% of infected healthcare workers or hospitalized patients.

The pooled percentage of asymptomatic infections was about 46% in North America, 44% in Europe and 28% in Asia.

“The high percentage of asymptomatic infections highlights the potential transmission risk of asymptomatic infections in communities,” wrote Min Liu and colleagues at Peking University in China. Officials should screen for asymptomatic infections, and those who are identified “should be under management similar to that for confirmed infections, including isolating and contact tracing.”

© 2021 Reuters

Adblock test (Why?)



Source link

Continue Reading

Health

Covid-19: World health officials offer hope that Omicron wave will increase global immunity – Hindustan Times

Published

 on


  • The encouraging trends after two years of coronavirus misery have brought a noticeably hopeful tone from health experts. Rosy predictions have crumbled before, but this time they are backed by what could be called Omicron’s silver lining. 

Covid-19: World health officials offer hope that Omicron wave will increase global immunity(Bhushan Koyande)
Published on Jan 25, 2022 08:59 AM IST
AP | | Posted by Krishna Priya Pallavi, Delhi

World health officials are offering hope that the ebbing of the omicron wave could give way to a new, more manageable phase of the Covid-19 pandemic, even as they warn of difficult weeks ahead and the possibility of another, more dangerous variant arising.

In the US, cases have crested and are dropping rapidly, following a pattern seen in Britain and South Africa, with researchers projecting a period of low spread in many countries by the end of March. Though US deaths — now at 2,000 each day — are still rising, new hospital admissions have started to fall, and a drop in deaths is expected to follow.

The encouraging trends after two years of coronavirus misery have brought a noticeably hopeful tone from health experts. Rosy predictions have crumbled before, but this time they are backed by what could be called Omicron’s silver lining: The highly contagious variant will leave behind extremely high levels of immunity.

On Sunday, Dr Anthony Fauci talked on ABC This Week about a “best-case scenario” where Covid-19 would fall to manageable levels so the United States could get “back to a degree of normality.”

And on Monday, the World Health Organization issued a statement anticipating an end to the “emergency phase” of the pandemic this year and saying that the omicron variant “offers plausible hope for stabilization and normalization.”

Both Fauci and the WHO’s Europe regional director, Dr Hans Kluge, cautioned that new variants are likely to emerge, but with vaccination, new drug therapies and — during surges — testing and masks, the world could reach a less disruptive level of disease in which the virus is, as Fauci put it, “essentially integrated into the general respiratory infections that we have learned to live with.”

In the US, new cases are averaging a still extraordinarily high 680,000 a day, down from an all-time peak of over 800,000 a little more than a week ago.

The places in the US where omicron struck first are seeing the sharpest declines. New cases in the Northeast are nose-diving, while other states — Arizona, Texas, Oregon, Kansas and North Dakota among them — are still waiting for relief.

Falling, too, are new US hospital admissions of patients with confirmed Covid-19. They are averaging nearly 20,000 per day, down about 7 per cent from the previous week, according to the Centres for Disease Control and Prevention.

Those numbers include patients who went to the hospital for other reasons and tested positive. But even after accounting for these incidental infections, the trend is hopeful.

One influential model projects that nearly all nations will be past the omicron wave by mid-March, including China and other countries with “zero Covid” policies. The wave will leave behind high levels of immunity — both from infection and vaccination — that could lead to low levels of transmission for many weeks or months.

“What do we end up with at the end of this?” said Dr Christopher Murray of the University of Washington, who developed the closely watched Institute for Health Metrics and Evaluation model. “We end up with the highest levels of global immunity that we’ve seen in the pandemic.”

The model estimates that 57% of the world’s population already has been infected with the virus at least once.

Another research group, which combines several models and shares the projections with the White House, predicts a strong decline in US infections by April, unless a new variant emerges that can sidestep the growing levels of immunity.

“It would be dangerous to forget that possibility, as it has caught us before,” said Katriona Shea of Pennsylvania State University, a leader of the team that pulls together the models.

She noted, too, that the projections show 16,000 to 98,000 more Americans dying before the omicron wave is through. The US death toll stands at close to 870,000.

“Even if we project a more optimistic future, right now we still have a lot of Covid spreading, a lot of strain in our hospital systems, and our deaths have not yet peaked,” said Lauren Ancel Meyers, director of the University of Texas Covid-19 Modeling Consortium.

“There’s still a lot of pain before omicron has run its course,” she said, but added: “It’s very plausible that omicron will be a turning point in terms of our relationship with this virus.”

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

Adblock test (Why?)



Source link

Continue Reading

Health

Factbox-Latest on the worldwide spread of the coronavirus

Published

 on

Britain said on Tuesday it needed to recruit 6,000 more people onto a trial of Merck‘s COVID-19 antiviral pill molnupiravir to inform how the drug can be rolled out more widely.

DEATHS AND INFECTIONS

* Eikon users, see COVID-19: MacroVitals https://apac1.apps.cp.thomsonreuters.com/cms/?navid=1592404098 for a case tracker and summary of news.

AMERICAS

* The U.S. health regulator revised the emergency use authorisations for COVID-19 antibody treatments from Regeneron and Eli Lilly to limit their use, as the drugs are unlikely to work against the Omicron variant.

* Brazil had 83,340 new cases of the novel coronavirus reported in the past 24 hours, and 259 deaths from COVID-19, the Health Ministry said on Monday.

* Chile, which already boasts one of the world’s highest COVID-19 vaccination rates, has agreed to purchase 2 million vaccine doses from Moderna, Chilean interim health minister Maria Teresa Valenzuela said.

* A New York judge struck down the state’s mask mandate, one week before it was due to expire, ruling the governor overstepped her authority in imposing a rule that needed to have been passed by the state legislature.

EUROPE

* The head of the World Health Organization warned that it was dangerous to assume the Omicron variant would herald the end of COVID-19’s acutest phase, exhorting nations to stay focused to beat the pandemic.

* Germany extended its current pandemic measures as the experts panel appointed by the government has warned the Omicron variant could bring critical infrastructure in Europe’s biggest economy to a breaking point.

ASIA-PACIFIC

* South Korea’s daily count of new coronavirus cases topped 8,000 for the first time, as the Omicron variant spreads rapidly despite the recent extension of strict social-distancing rules to slow infection.

* Japan is set to more than double the number of regions under enhanced coronavirus curbs on Tuesday, even as it sought to modify strategies to contend with the infectious Omicron variant that has fuelled record numbers of cases.

* About two dozen cases of COVID-19 have been recorded among the crew of an Australian warship expected to arrive in coronavirus-free Tonga on Wednesday to deliver humanitarian aid, Australian authorities said.

AFRICA AND MIDDLE EAST

* Israel’s health minister said he did not think Israel will offer a fourth COVID-19 vaccine dose to most people after the government made it available to over 60s and other high-risk groups.

MEDICAL DEVELOPMENTS

* Omicron can survive longer than earlier versions of the coronavirus on plastic surfaces and human skin, Japanese researchers found in laboratory tests.

* A third booster dose of a COVID-19 vaccine made by AstraZeneca, Pfizer-BioNTech or Johnson & Johnson increases antibody levels significantly in those who have previously received two doses of Sinovac’s CoronaVac shot, a study has found.

ECONOMIC IMPACT

* Australia’s core inflation flew to its fastest annual pace since 2014 in the December quarter as fuel and housing costs led broad-based price pressures, a shock that will stoke market speculation of an early hike in interest rates.

* South Korea’s economy expanded at the fastest pace in 11 years in 2021, helped by a jump in exports and construction activity, tempering declines in capital investment and a slow recovery in the coronavirus-hit service sectors.

* A measure of Australian business confidence has swung into the red as a surge in coronavirus cases hit consumer spending and played havoc with staffing, though sales overall were proving resilient so far.

 

(Compiled by Sherry Jacob-Phillips; Edited by Shounak Dasgupta)

Continue Reading

Health

Sinovac regimen gets strong boost from Pfizer, AstraZeneca or J&J COVID shots – study

Published

 on

A third booster dose of a COVID-19 vaccine made by AstraZeneca, Pfizer-BioNTech or Johnson & Johnson increases antibody levels significantly in those who have previously received two doses of Sinovac’s CoronaVac shot, a study has found.

The study found that CoronaVac received the strongest boost from a viral vector or RNA shot, including against the Delta and Omicron coronavirus variants, researchers from Brazil and Oxford University said on Monday.

China-based Sinovac’s vaccine uses an inactivated version of a coronavirus strain that was isolated from a patient in China. It is currently approved in more than 50 countries including Brazil, China, Argentina, South Africa, Oman, Malaysia, Indonesia and Turkey.

“This study provides important options for policymakers in the many countries where inactivated vaccines … have been used,” said Andrew Pollard, director of the Oxford Vaccine Group and study lead.

However, another study in December found that Sinovac’s two-dose shot followed by a booster dose of Pfizer-BioNTech’s vaccine showed a lower immune response against the Omicron variant compared with other strains.

Viral vector vaccines such as the ones developed by AstraZeneca-Oxford and J&J use a weakened version of another virus to deliver genetic instructions for making proteins from the virus against which protection is sought. Pfizer and BioNTech’s mRNA vaccines deliver a genetic transcript with instructions for making viral proteins to teach the body how to defend against infections.

A third dose of CoronaVac also increased antibodies, but the results were better when a different vaccine was used, according to the latest study that included 1,240 volunteers from the Brazilian cities of Sao Paulo and Salvador.

Antibody levels were low before the booster doses, with only 20.4% of adults aged 18-60 and 8.9% of adults aged over 60 having detectable levels of neutralising antibodies. These were seen to significantly increase across every booster vaccine regimen, according to the study, which was published in the Lancet medical journal on Friday.

 

(Reporting by Aby Jose Koilparambil and Pushkala Aripaka in Bengaluru; Editing by Ramakrishnan M.)

Continue Reading

Trending