Tuesday, December 14, 2021
U.K. Study Says Boosters Provide Substantial Defense Against Omicron
The first real-world study of how vaccines hold up against the Omicron variant showed a significant drop in protection against symptomatic cases caused by the new and fast-spreading form of the coronavirus.
But the study, published by British government scientists on Friday, also indicated that third vaccine doses provided considerable defense against Omicron.
Government scientists on Friday also offered the most complete look yet at how quickly Omicron was spreading in England’s highly vaccinated population, warning that the variant could overtake Delta by mid-December and, without any precautionary measures, cause Covid-19 cases to soar.
Four months after people received a second dose of the Pfizer-
BioNTech vaccine, the shots were roughly 35 percent effective in preventing symptomatic infections caused by Omicron, a significant drop-off from their performance against the Delta variant, the scientists found.
A third dose of the Pfizer-BioN- Tech vaccine, though, lifted the figure to roughly 75 percent.
Two doses of the AstraZeneca vaccine appeared to offer virtually no protection against symptomatic infection caused by Omicron several months after vaccination. But for those recipients, an additional Pfizer-BioNTech dose paid big dividends, boosting effectiveness against the variant to 71 percent.
Still, the study’s authors said they expected that the vaccines would remain a bulwark against hospitalizations and deaths, if not infections, caused by Omicron. And the researchers cautioned that even in a country tracking the variant as closely as Britain is, it was too early to know precisely how well the vaccines would perform.
That study was released alongside new findings about how easily Omicron is managing to spread. Someone infected with the Omicron variant, for example, is roughly three times as likely as a person infected by the Delta variant to pass the virus to other members of his or her household, Britain’s Health Security Agency reported.
And a close contact of an Omicron case is roughly twice as likely as a close contact of someone infected with Delta to catch the virus.
Neil Ferguson, an epidemiologist at Imperial College London, said that Omicron’s ability to evade the body’s immune defenses accounted for most of its advantage over previous variants. But modeling work by his research team and other groups in Britain also suggested that Omicron was simply more contagious than Delta, by roughly 25 to 50 percent.
Covid-19 cases have been doubling every 2.5 days in England.
“I think that there’s a significant amount of immune escape,” Dr. Ferguson said, referring to the virus’s ability to dodge the body’s defenses. “But it’s also more intrinsically transmissible than Delta.”
He and other scientists have cautioned that evidence was still coming in, and that better surveillance in places where the Omicron wave is most advanced could affect their findings.
The World Health Organization said this week that some evidence had emerged that Omicron was causing milder illness than Delta, but that it was too early to be certain. Still, scientists have warned that if the variant keeps spreading as quickly as it is in England, where cases are doubling every 2.5 days, health systems around the world may be deluged with patients.
Even if Omicron causes severe illness at only half the rate of the Delta variant, Dr. Ferguson said, computer modeling suggested that 5,000 people could be admitted to hospitals daily in Britain at the peak of its Omicron wave —a figure higher than any seen at any other point in the pandemic.
Scientists said that widespread vaccination in countries like Britain and the United States would keep as many people from dying as have in earlier waves. But the experts also warned that patients with Covid and with other illnesses would suffer if hospitals became too full.
“It only requires a small drop in protection against severe disease for those very large numbers of infections to translate into levels of hospitalization we can’t cope with,” Dr. Ferguson said.
It will take several weeks to understand how the current surge in Omicron infections may translate into people needing hospital care. “I’m concerned that by the time we know about severity,” Dr. Ferguson said, “it may be too late to act.”
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Three shots of Pfizer vaccine DOES protect against Omicron - but at four times lower levels than against the Delta variant, Israeli study shows
Israeli researchers have found that a three-shot course of the Pfizer/BioNTech COVID-19 vaccine provides significant protection against the new Omicron variant.
The study, carried out by Sheba Medical Centre and the Health Ministry's Central Virology Laboratory, compared the blood of 20 people who had received two vaccine doses 5-6 months earlier to the same number of individuals who had received a booster a month before.
Gili Regev-Yochay, director of the Infectious Diseases Unit at Sheba, said: 'People who received the second dose 5 or 6 months ago do not have any neutralisation ability against the Omicron. While they do have some against the Delta strain.
'The good news is that with the booster dose it increases about a hundred fold. There is a significant protection of the booster dose.'
But Regev-Yochay also admitted that the booster is still less effective in protecting against Omicron versus the Delta variant. 'It is lower than the neutralisation ability against the Delta, about four times lower,' she said.
The findings were similar to those presented by BioNTech and Pfizer earlier in the week, which were an early signal that booster shots could be key to protect against infection from the newly identified variant.
The Israeli team said they worked with the actual virus while the companies used what is known as a pseudovirus, which was bio-engineered to have the hallmark mutations of Omicron.
The Israeli research follows a study from South Africa that found the Omicron variant can partially evade protection from two doses.
'People who have received the booster are better protected than those who received only the second, and of course, more than the unvaccinated,' said Dr. Sharon Alroy-Preis, Israel's health department's head of public health services,
'Two doses are not effective enough.'
Alroy-Preis also announced that the health ministry in Israel is debating whether to encourage people to take their booster shot as soon as three months after receiving their second jab to ensure maximum protection.
It comes less than a month after BioNTech announced it had begun working on a Covid vaccine specifically targeting the Omicron variant.
Despite the latest news that a third shot of the Pfizer/BioNTech could provide considerable protection against Omicron, the company said in late November it could have a tailor-made vaccine against Omicron ready for distribution within 100 days.
'The first steps of developing a potential new vaccine overlap with the research necessary in order to evaluate whether a new shot will be needed,' the company said.
Moderna also announced last month it is developing a booster which it says will provide protection targeted against the Omicron variant.
Despite the news that booster jabs can provide significant protection against Omicron, Israel today announced that its citizens will be banned from travelling to Britain, Denmark and Belgium from Wednesday due to the spread of the new variant.
Alroy-Preis said the three countries are being placed on the 'red' list because of the 'significant' spread of the Omicron variant.
Since the Omicron variant was discovered, some 50 countries have been placed on Israel's red list, mostly in Africa.
Health officials said there have been 55 confirmed cases of Omicron in Israel, which motivated the government and health ministry to enforce stricter mask mandates.
It was also decided that Green Pass restrictions in the country would be introduced at shopping centres, meaning unvaccinated Israelis cannot enter.
The Prime Minister Naftali Bennett is facing calls to impose tougher restrictions in Israel over the coming days.
It comes after the spread of the virus yesterday hit a three-month peak and the R-number climbed to 1.1.
Previously, Israel imposed a two-week ban on foreigners entering the country in late November in an attempt to stem coronavirus infections.
And Israelis entering the country, including those who are vaccinated, are required to quarantine.
The country also brought back counter-terrorism phone-tracking technology in a bid to crack down on the Omicron variant.
The Shin Bet counter-terrorism agency's phone-tracking technology is used to locate carriers of the new variant in order to curb its transmission to others, Bennett said in November.
Used on and off since March 2020, the surveillance technology matched virus carriers' locations against other mobile phones nearby to determine with whom they had come into contact.
Israel's Supreme Court this year limited the scope of its use after civil rights groups mounted challenges over privacy concerns.
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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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