The first real study on the resistance of vaccines to the Omicron variant showed a significant decrease in protection against symptomatic conditions caused by a new and rapidly spreading form of the coronavirus.
On Friday, government scientists also provided the most complete information on how fast Omicron is spreading in the UK’s highly vaccinated population, and that this option could cross the Delta in mid-December and increase the incidence of Covid-19 cases without any precautions. warned that it could lead to seizures.
These warnings have been backed up by a UK computer modeling study released on Saturday that Omicron could significantly disrupt lives and invade hospitals, even in immunocompromised populations. As scientists learn more about the severity of Omicron infection, they warned that these prognosis could change.
A vaccine study released on Friday showed a drop in protection levels. Four months after humans received the second dose of the Pfizer-BioNTech vaccine, the vaccines were approximately 35 percent effective in preventing symptomatic infections caused by Omicron, significantly reducing their effectiveness compared to the Delta variant.
The third dose of Pfizer-BioNTech vaccine increased this figure by about 75 percent.
Two doses of the AstraZeneca vaccine showed virtually no protection against the symptomatic infection caused by Omicron a few months after vaccination. But for these recipients, the additional Pfizer-BioNTech dose yielded significant dividends and increased efficiency by 71 percent compared to this option.
Nevertheless, the study authors expected that vaccines would remain a means of protection against hospitalization and death, even if there were no infections caused by Omicron. And researchers warn that it is too early to know how well the vaccines will work in a country like Britain, which is closely monitoring the option.
This study was published along with new findings on how easily Omicron spreads. For example, a person infected with the Omicron variant is about three times more likely to transmit the virus to other members of their family than a person infected with the Delta variant, according to the British Health Safety Agency.
And being in close contact with the Omicron case is twice as likely as a person with Delta to become infected with the virus.
Neil Ferguson, an epidemiologist at Imperial College London, points out that Omicron’s ability to escape the body’s immune defenses has many advantages over its predecessors. But modeling work by his research team also showed that the Omicron Delta is about 25-50 percent more contagious.
Dr. Ferguson, referring to the virus’s ability to bypass the body’s defenses, said, “I think there is a significant amount of immunity.” “But it’s more spontaneous than Delta.”
He and other scientists warned that evidence was still coming and that better observation of the Omicron wave in the most developed areas could affect their findings.
The World Health Organization said there was some evidence this week that the Omicron caused a milder illness than the Delta, but it was too early to be sure. Still, scientists warn that if this option spreads as fast as it does in the UK, which doubles every 2.5 days, health care systems around the world could become overcrowded with patients.
According to Dr. Ferguson, even if the Omicron Delta variant causes serious illness in only half of its cases, its computer modeling has shown that at the peak of the Omicron wave, 5,000 people can be admitted to hospitals in the UK every day – that’s a lot. higher than all the indicators shown. at any other point of the pandemic.
Scientists say the vaccine, which is widespread in countries like the United Kingdom and the United States, will prevent as many deaths as in previous waves. But experts also warned that patients with Covid and other illnesses would suffer if hospitals were full.
“This requires a slight reduction in protection against serious illness so that a large number of infections can become a level of hospitalization that we cannot tolerate,” Dr. Ferguson said.
It will take several weeks to understand how the current proliferation of Omicron infections is turning into people in need of hospital care. “I’m worried it may be too late to act once we know about the seriousness,” Dr. Ferguson said.
A modeling study released on Saturday by a separate panel of experts from the London School of Hygiene and Tropical Medicine significantly eased the possibility of an increase in hospitalizations. So far, those scientists have predicted that Omicron Delta will cause as serious a disease as it does in unvaccinated people, but an increase in immunity to vaccines and previous infections will soften the Omicron wave, as it did in South Africa.
In a scenario reported by some external experts – Omicron significantly bypassing people’s immunity, but boosting doses were also very effective – scientists said it would hit the UK hard. By April, they had estimated about 300,000 hospitalizations and 47,000 deaths.
This could be a greater daily burden on British hospitals at the peak of the Omicron wave than during the pandemic period.
Importantly, scientists point out that reintroducing certain restrictions could save the lives of thousands of people and save tens of thousands of people from being hospitalized.
External experts noted that Omicron is still not well understood, that people can fight severe infections more effectively than predicted, and that the arrival of new antiviral pills in the coming months will alleviate the impact of infections.
Still, the scientists called on governments to speed up vaccination campaigns, share doses with less vaccinated countries, and consider measures such as self-testing, even if there are no new restrictions.
“The coronavirus doesn’t end with us,” said Michael Head, a senior global health researcher at the University of Southampton in the UK.
“Turning off the lights and pretending we weren’t involved is a failed policy.”