Catching Omicron strain may protect against Delta and usher in endemic phase of Covid, study suggests
Academics took blood samples from people struck down with the ultra-infectious variant and measured their antibody levels. They then looked at how well the virus-fighting proteins reacted to both Omicron and Delta.
Lab tests, conducted two weeks after patients joined the study, showed antibody levels spiked 14-fold in response to Omicron.
But there was also a 4.4-fold increase against Delta, according to the findings which took the researchers by surprise.
Other studies delving into the topic of cross-variant immunity showed antibodies made in response to Delta reacted poorly to Omicron.
Professor Alex Sigal, a virologist at the University of KwaZulu-Natal in South Africa who led the research, said it suggested Omicron could usher in the endemic phase of the pandemic. He said: 'The increase in neutralising immunity against Omicron was expected, that is the virus these individuals were infected with.
'However, we also saw that the same people — especially those who were vaccinated — developed enhanced immunity to the Delta variant.'
Professor Alex Sigal, a virologist at the University of KwaZulu-Natal, found in research that infections with the super-variant also boost protection against Delta.
He said: 'If, as it currently looks like from the South African experience, Omicron is less pathogenic, then this will help push Delta out as it should decrease the likelihood that someone infected with Omicron will get re-infected with Delta.
'If that's true, then the disruption Covid has caused in our lives may become less.'
Professor Nathan Grubaugh, a virologist from Yale University, told the New York Times that the results matched observations on the ground.
He said: 'We are seeing Omicron exponentially rise while Delta cases are falling.
'This suggests to me that Omicron is outcompeting Delta for susceptible individuals, leaving them less susceptible to Delta in the aftermath and driving down Delta cases.'
UK data shows that Delta cases fell 24 per cent over the fortnight to December 18, the latest available, while Omicron infection skyrocketed.
It comes amid the roll out of boosters in the country, which bolster protection against the variant.
Professor Sigal added: 'If, as it currently looks like from the South African experience, Omicron is less pathogenic, then this will help push Delta out.'
He said this was because it should 'decrease the likelihood someone infected with Omicron will get re-infected with Delta'.
'If that is true, then the disruption Covid has caused in our lives may become less,' Professor Sigal continued.
An ever-growing body of evidence shows Omicron is milder than its rivals, and less likely to put people who catch it in hospital.
The variant is already dominant in Britain, and has caused cases to hit record levels.
It has also driven a surge in infections in the US, which has seen infections top 500,000 a day — also a record high.
In the new research, Professor Sigal and colleagues analysed blood from 13 patients who had recovered from Omicron. Six were unvaccinated.
And the majority of the volunteers had been hospitalised during their battle with the virus.
Their blood samples were then tested in laboratory experiments against live versions of both the Omicron and Delta variants.
The paper was published as a preprint on MedRxiv, and is yet to be peer-reviewed by other scientists.
But Professor Nathan Grubaugh, a virologist from Yale University, told the New York Times that the results matched observations on the ground.
He said: 'We are seeing Omicron exponentially rise while Delta cases are falling.
'This suggests to me that Omicron is outcompeting Delta for susceptible individuals, leaving them less susceptible to Delta in the aftermath and driving down Delta cases.'
Scientists did not confirm whether the individuals had previously been infected with Delta, which could have skewed the results.
But this is likely to have been the case because of South Africa's mammoth waves of infection.
Previous research has suggested that people who had previously been infected with Covid were less likely to catch other variants of the virus.
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CDC admits that its PCR test for Covid is not fit for purpose
07/21/2021: Lab Alert: Changes to CDC RT-PCR for SARS-CoV-2 Testing
CDC's Laboratory Outreach Communication System (LOCS)
Audience: Individuals Performing COVID-19 Testing
Level: Laboratory Alert
After December 31, 2021, CDC will withdraw the request to the U.S. Food and Drug Administration (FDA) for Emergency Use Authorization (EUA) of the CDC 2019-Novel Coronavirus (2019-nCoV) Real-Time RT-PCR Diagnostic Panel, the assay first introduced in February 2020 for detection of SARS-CoV-2 only. CDC is providing this advance notice for clinical laboratories to have adequate time to select and implement one of the many FDA-authorized alternatives.
Visit the FDA website for a list of authorized COVID-19 diagnostic methods. For a summary of the performance of FDA-authorized molecular methods with an FDA reference panel, visit this page.
In preparation for this change, CDC recommends clinical laboratories and testing sites that have been using the CDC 2019-nCoV RT-PCR assay select and begin their transition to another FDA-authorized COVID-19 test. CDC encourages laboratories to consider adoption of a multiplexed method that can facilitate detection and differentiation of SARS-CoV-2 and influenza viruses. Such assays can facilitate continued testing for both influenza and SARS-CoV-2 and can save both time and resources as we head into influenza season. Laboratories and testing sites should validate and verify their selected assay within their facility before beginning clinical testing.
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How long is Omicron’s incubation period? How it differs from Delta and other Covid variants
One thing that has become clear over the last few weeks is how the Omicron variant differs from the original Covid strain.
While the World Health Organisation estimated that symptoms took anywhere between two days to two weeks to materialise in cases of people infected with the first coronavirus strain, the Omicron variant is thought to incubate much faster, closer to three to five days.
“Recent analysis from the UK Health Security Agency suggests that the window between infection and infectiousness may be shorter for the Omicron variant than the Delta variant,” UK health secretary Sajid Javid told MPs.
That would explain why it has spread so swiftly and successfully, as the shortness of its incubation period gives sufferers a shorter window between suspecting they have contracted the virus and experiencing a flare-up, making it less likely a positive test result will be recorded in time to warn others, enter isolation and prevent the contagion being passed on.
A shorter incubation period “makes a virus much, much, much harder to control,” Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Center for Health Security, warned The Atlantic this week.
Another aspect of Omicron that makes it potentially harder to detect than other strains is that its symptoms differ somewhat from the three primary indicators we have learned to be on the lookout for: coughs, fever and any loss of sense of taste or smell.
Early warning signs for the new variant, by contrast, include a scratchy throat, lower back pain, a runny or blocked nose, a headache, muscle pains and fatigue, sneezing and night sweats.
The current evidence from Omicron cases analysed in Britain is that patients will recover within five days to a week on average, although some of the symptoms like coughing and fatigue may linger for longer.
Shortness of breath has also been reported in more severe cases, which has been seen to last for as long as 13 days after.
Covid sufferers are, typically, thought to be infectious to others from around two days before their first symptoms start to materialise and for around 10 days after.
https://www.independent.co.uk/news/health/incubation-period-omicron-variant-uk-delta-b1983692.html
*********************************************Also see my other blogs. Main ones below:
http://edwatch.blogspot.com (EDUCATION WATCH)
http://antigreen.blogspot.com (GREENIE WATCH)
http://pcwatch.blogspot.com (POLITICAL CORRECTNESS WATCH)
http://australian-politics.blogspot.com/ (AUSTRALIAN POLITICS)
http://snorphty.blogspot.com/ (TONGUE-TIED)
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