Connect with us

Health

COVID-19 vaccine booster protection against Omicron fades within 10 weeks, says new study – Republic World

Published

 on


In a more concerning development, the efficacy of the mRNA Pfizer’s booster shot against symptomatic COVID-19 infection from the Omicron variant waned in just 10 weeks after the third shot, a new study has found this week. As the highly complex strain with more than 65 mutations and 32 mutations on spike protein has been spreading like wildfire, pushing cases of coronavirus to more than 100,000 for the first time since the pandemic hit in the UK, scientists and health experts have been weighing into the protection the vaccines provided against this hyper transmissible variant.

Unlike COVID-19 caused by other variants, Omicron has been showing unique symptoms among the patients along with the usual “high temperature, a new, continuous cough, or a loss or change to a sense of smell or taste” noticed in the case of Delta. Those who contracted Omicron also noted several other symptoms which aren’t usually associated with coronavirus, such as nausea and a loss of appetite.

Immunity offered by boosters ‘wanes more quickly’

But more worryingly, Britain’s Health Security Agency outlined the surveillance analyses related to risk assessments of B.1.1.529. It stressed that immunity offered by vaccines wanes more quickly with omicron than was previously seen in any other variant including SARS-CoV-2. “The protection conferred by booster vaccines against the omicron variant begins to wane within 10 weeks,” according to the technical briefing released by the UK Health Security Agency (UKHSA). British agency’s analysis was based on research of 147,597 Delta and 68,489 Omicron cases. Researchers shockingly found that Oxford/AstraZeneca, Pfizer/BioNTech, and Moderna COVID-19 vaccines are less effective against Omicron than Delta.

“There is evidence of waning of protection against symptomatic disease with increasing time after dose 2, and by 10 weeks after the booster dose, with a 15 to 25% reduction in vaccine effectiveness after 10 weeks,” the UKHSA said.

“This waning is faster for Omicron than for Delta infections. There are insufficient severe cases of Omicron as yet to analyze vaccine effectiveness against hospitalisation.” 

For those who received 2 shots of the Oxford/AstraZeneca vaccine, the third booster shot of Pfizer/BioNTech or Moderna will only be 60% effective at preventing symptomatic COVID-19 infection 2 to 4 weeks after the third booster dose. But this protection fades to just 35% to 45%  by 10 weeks. And those who received two initial doses of Pfizer/BioNTech, protection against Omicron falls from 70% at 2 to 4 weeks to 45% at 10 weeks after they take a Pfizer booster shot. The protection however falls to 70% to 75% by the 9th week after a Moderna booster shot. 

Some Omicron cases ‘third’ episode of reinfection

The UKHSA report also estimates that those infected with the B.1.1.529 variant may be 50% less likely to be admitted to the hospital, while a separate study published by Imperial College London found the risk was 15 to 20% lower compared to Delta. The vulnerable population or those with comorbidity may however face more serious COVID-19 and therefore health safety precautions are recommended.

The reinfection rate has increased sharply and disproportionately with Omicron, as per the UK agency. There are 69 identified cases with Omicron which are a “third” episode of infection, at least 290 cases of Omicron infection were recovered COVID-19 cases between a 60 to an 89-day interval of the recovery period. 

Britain’s Health Security Agency categorically stresses that to avoid the similar levels of hospital admission witnessed during the Delta wave, the Omicron B.1.1.529 strain will have to be 90% less severe than all strains previously detected. But the rate of spread of the new variant is dramatically worrying and risks overwhelming the hospitals, the UK government’s Scientific Advisory Group for Emergencies stated in the study.

“What we have got now is a really fine balance between something that looks like a lower risk of hospitalization – which is great news – but equally a highly transmissible variant and one that we know evades some of our immune defenses, so it is a very balanced position,” Jenny Harris, chief executive of UKHSA, told the Today programme, BBC Radio 4.

Just yesterday, the UK has recorded 119,789 new cases of COVID-19 shattering all records of the previous several months. UK’s Office for National Statistics estimates that 1.4 million people have contracted the COVID-19 this week. This is the highest yet comparable figure that was recorded in autumn 2020 during initial pandemic waves. “Omicron has continued to increase sharply as a proportion of cases in England, it is predominant in all regions of England,” the UK agency stressed. “The increase is also visible in wastewater, particularly in London and the South East,” it added. While Omicron has been behind the large community transmission, relative to Delta, it is currently more concentrated in young adult age groups between 20 to 29, the UKHSA warned. London, thus far as per the data until Dec. 20 has seen 40% hospitalizations from the Omicron variant. 

Of those hospitalized in London, 17 (12.9%) had received a booster dose, 74 (56.1%) a second dose, and 27 (20.5%) were not vaccinated (less than 10 were unlinked or had one dose). At least 14 people died within 28 days of an Omicron diagnosis, age range 52 to 96 years. The risk of hospital admission for a person detected as a case of Omicron appears reduced compared to a case of Delta. But this analysis is preliminary because of the small numbers of Omicron cases currently in hospital, and the limited spread of Omicron worldwide as the variant is in the initial stages of transmission and has not reached older age groups as yet, UKHSA noted. 

Adblock test (Why?)



Source link

Continue Reading

Health

Over 1.2 million people died from drug-resistant infections in 2019 – study

Published

 on

More than 1.2 million people died in 2019 from infections caused by bacteria resistant to multiple antibiotics, higher than HIV/AIDS or malaria, according to a new report published on Thursday.

Global health officials have repeatedly warned about the rise of drug-resistant bacteria and other microbes due to the misuse and overuse of antibiotics, which encourages microorganisms to evolve into “superbugs”.

The new Global Research on Antimicrobial Resistance report, published in The Lancet, revealed that antimicrobial resistance (AMR) was directly responsible for an estimated 1.27 million deaths and associated with about 4.95 million deaths. The study analysed data from 204 countries and territories.

“These new data reveal the true scale of antimicrobial resistance worldwide… Previous estimates had predicted 10 million annual deaths from AMR by 2050, but we now know for certain that we are already far closer to that figure than we thought,” said Chris Murray, co-author of the study and a professor at the University of Washington.

Last year, the World Health Organization warned that none of the 43 antibiotics in development or recently approved medicines were enough to combat antimicrobial resistance.

Cornelius Clancy, professor of Medicine at the University of Pittsburgh, said one of the ways to tackle AMR is to look at a new treatment model.

“The traditional antibiotic model that we’ve had for past number of decades since penicillin. I think it is tapped out.”

Most of 2019’s deaths were caused by drug resistance in lower respiratory infections such as pneumonia, followed by bloodstream infections and intra-abdominal infections.

AMR’s impact is now most severe in Sub-Saharan Africa and South Asia, while around one in five deaths is in children aged under five years.

There was limited availability of data for some regions, particularly many low and middle-income countries, which may restrict the accuracy of the study’s estimates.

Clancy said the focus has been on COVID-19 for the past two years, but AMR is a “long-term kind of challenge”.

 

(Reporting by Mrinalika Roy in Bengaluru; Editing by Krishna Chandra Eluri and Devika Syamnath)

Continue Reading

Health

Study casts doubt on reliability of rapid antigen tests in kids; COVID transmission through breastmilk unlikely

Published

 on

The following is a summary of some recent studies on COVID-19. They include research that warrants further study to corroborate the findings and that has yet to be certified by peer review.

Rapid antigen tests may be unreliable in children

When used in children, rapid antigen tests for detecting the coronavirus do not meet accuracy criteria set by the World Health Organization and U.S. and UK device regulators, according to researchers who reviewed 17 studies of the tests.

The trials evaluated six brands of tests in more than 6,300 children and teenagers through May 2021. In all but one study, the tests were administered by trained workers. Overall, compared to PCR tests, the antigen tests failed to detect the virus in 36% of infected children, the researchers reported on Tuesday in BMJ Evidence-Based Medicine. Among children with symptoms, it missed 28% of infections. Among infected kids without symptoms, the tests missed the virus in 44%. Only about 1% of the time did the tests mistakenly diagnose the virus in a child who was not actually infected.

Given that more than 500 antigen tests are available in Europe alone, the authors said, “the performance of most antigen tests under real-life conditions remains unknown.” But the new findings “cast doubt on the effectiveness” of rapid antigen tests for widespread testing in schools, they concluded.

Breastmilk transmission of COVID-19 unlikely

A new study appears to confirm smaller, earlier studies that suggested nursing mothers are unlikely to transmit the coronavirus in breastmilk.

Between March and September 2020, researchers obtained multiple breastmilk samples from 110 lactating women, including 65 with positive COVID-19 tests, 36 with symptoms who had not been tested, and a control group of 9 women with negative COVID-19 tests. Seven women (6%) – six with positive tests and one who had not been tested – had non-infectious genetic material (RNA) from the virus in their breastmilk, but none of the samples had any evidence of active virus, according to a report published on Wednesday in Pediatric Research. Why breastmilk would contain coronavirus RNA but not infectious virus is unclear, said study leader Dr. Paul Krogstad of the David Geffen School of Medicine at UCLA, “Breastmilk is known to contain protective factors against infection, including antibodies that reflect both the mother’s exposure to viruses and other infectious agents and to vaccines she has received,” he noted.

The U.S. Centers for Disease Control and Prevention (CDC) advises that before breastfeeding, bottle-feeding, or expressing milk, women with COVID-19 should wash their hands or use hand sanitizer with at least 60% alcohol. The CDC also recommends that they wear a mask when within 6 feet (1.8 meters) of the baby.

New technique may speed vaccine, antibody drug development

Researchers are working on a way to speed development of vaccines and monoclonal antibody drugs for COVID-19 and other illnesses, shortening the time from collection of volunteers’ blood samples to identification of potentially useful antibodies from months to weeks.

As described in Science Advances on Wednesday, the new technique employs cryo-electron microscopy, or cryoEM, which involves freezing the biological sample to view it with the least possible distortion. Currently, “generation of monoclonal antibodies involves several steps, is expensive, and typically takes somewhere on the order of two to three months, and at the end of that process you still need to perform structural analysis of the antibodies” to figure out where they attach themselves to their target, and how they actually work, explained Andrew Ward of Scripps Research Institute in La Jolla, California.

In experiments using the new approach to look for antibodies to HIV, “we flipped the process on its head… by starting with structure,” Ward said. Because cryoEM affords such high resolution, instead of having to laboriously sort through antibody-producing immune cells one by one to identify promising antibodies, the process of identifying antibodies, mapping their structure and seeing how they are likely to attack viruses and other targets goes much faster, he added. “The ongoing COVID-19 pandemic has highlighted the need for such robust and rapid technologies,” his team concluded.

Click for a Reuters graphic on vaccines in development.

 

(Reporting by Nancy Lapid; Editing by Bill Berkrot)

Continue Reading

Health

Vaccination plus infection offered most protection during Delta surge, U.S. study shows – CBC News

Published

 on


Protection against the previously-dominant Delta variant was highest among people who were both vaccinated and had survived a previous COVID-19 infection, according to a report published Wednesday by the U.S. Centers for Disease Control and Prevention (CDC).

The report also found those who had previously been infected with COVID-19 were better protected against the Delta variant than those who were vaccinated alone, suggesting that natural immunity was a more potent shield than vaccines against that variant, California and New York health officials reported on Wednesday.

Protection against Delta was lowest among those who had never been infected or vaccinated, the CDC report continued.

“The evidence in this report does not change our vaccination recommendations,” Dr. Ben Silk of the CDC and one of the study’s authors told a media briefing.

“We know that vaccination is still the safest way to protect yourself against COVID-19,” he said.

The findings do not apply to the Omicron variant of the virus, which now accounts for 99.5 per cent of COVID-19 cases in the United States.

Study includes data from May to November

For the study, health officials in California and New York gathered data from May through November, which included the period when the Delta variant was dominant.

It showed that people who survived a previous infection had lower rates of COVID-19 than people who were vaccinated alone.

That represented a change from the period when the Alpha variant was dominant, Silk told the briefing.

“Before the Delta variant, COVID-19 vaccination resulted in better protection against a subsequent infection than surviving a previous infection,” he said.

In the summer and fall of 2021, however, when Delta became the predominant circulating iteration of the virus in the United States, “surviving a previous infection now provided greater protection against the subsequent infection than vaccination,” he said.

But acquiring immunity through natural infection carries significant risks. According to the study, by Nov. 30, 2021, roughly 130,781 residents of California and New York had died from COVID-19.

The analysis did not include information on the severity of initial infection, nor does it account for the full range of illness caused by prior infection.

One important limitation to the study was that it ended before administration of vaccine booster doses was widespread.

WATCH | Experts agree the science behind booster shots is sound:

The safe science behind COVID-19 booster shots

5 days ago

Duration 1:55

While some Canadians who have received their booster shots have later tested positive for COVID-19, medical experts agree that the science behind booster jabs is sound. 1:55

‘Clearly shows’ vaccines provide safest protection

Dr. Erica Pan, state epidemiologist for the California Department of Public Health, said in an email that the study “clearly shows” that vaccines provide the safest protection against COVID-19 and they offer added protection for those with prior infections.

“Outside of this study, recent data on the highly contagious Omicron variant shows that getting a booster provides significant additional protection against infection, hospitalization and death,” Pan said.

Silk said the CDC is studying the impact of vaccination, boosters and prior infection during the Omicron surge and expects to issue further reports when that data becomes available.

So far, Omicron has proven to evade some level of immunity from both vaccination and previous infection, but vaccines are still largely preventing serious illness and death.

An Israeli hospital on Monday also said preliminary research indicates a fourth dose of leading mRNA-based vaccines provides only limited defence against infection from the variant.

Adblock test (Why?)



Source link

Continue Reading

Trending