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Virus Notebook

Pfizer, BioNTech say tests suggest 3 doses protect against Omicron

Syringes filled with the Pfizer-BioNTech COVID-19 vaccine used for booster shots at Chiba University Hospital in Chiba, Japan.Noriko Hayashi/Bloomberg

Pfizer and BioNTech said Wednesday that laboratory tests suggest that three doses of their coronavirus vaccine offer significant protection against the fast-spreading Omicron variant of the virus.

The companies said that tests of blood from people who received only two doses found much lower antibody levels against the Omicron variant compared with an earlier version of the virus. That finding indicates that two doses alone “may not be sufficient to protect against infection” by the new variant, the companies said.

But the blood samples obtained from people one month after they had received a booster shot showed neutralizing antibodies against the Omicron variant comparable to those against previous variants after two doses, the companies said in a statement.


These experiments, done with blood samples in the lab, cannot say for sure how the vaccines will perform in the real world. Vaccines stimulate a wide-ranging immune response that involves more than just antibodies. So the experiments offer an incomplete picture of how well the vaccine will protect against severe outcomes from Omicron.

Still, the results seemed to underscore the importance of booster shots in combating infection from the new variant. “Our preliminary, first data set indicate that a third dose could still offer a sufficient level of protection from disease of any severity caused by the Omicron variant,” said Dr. Ugur Sahin, the chief executive officer of BioNTech, Pfizer’s German partner.

Dr. Albert Bourla, the chairman and chief executive officer of Pfizer, said while two doses may still prevent severe disease from Omicron, “it’s clear from these preliminary data that protection is improved with a third dose of our vaccine.”

Dr. Peter Hotez, a vaccine expert with the Baylor College of Medicine, called the results “really good news.” But he noted that Pfizer’s experiments only measured the levels of neutralizing antibodies one month after the third shot, saying he was concerned by other research suggesting that those levels might drop off later, more sharply than expected.


The results come one day after a preliminary report on laboratory experiments in South Africa also found Omicron seemed to dull the power of two doses of Pfizer’s vaccine. The South African experiments did not try to evaluate how well three doses worked.

The Omicron variant has now spread to dozens of countries, and while the Delta variant is still overwhelmingly dominant in the United States, the Biden administration is bracing for a new flood of cases from Omicron.

At a White House briefing Tuesday, Dr. Anthony S. Fauci, the government’s top infectious disease expert, said it would still be weeks before scientists understand how virulent the Omicron variant is.

“We shouldn’t be making any definitive conclusions, certainly not before the next couple of weeks,” he said.

He said early reports from South African medical officials presented a somewhat hopeful picture of Omicron’s impact. Researchers at a major hospital complex in Pretoria reported this week that patients with the coronavirus are significantly less ill than those they have treated before and that other hospitals are seeing the same trends.

New York Times

WHO says early data suggests Omicron causes mild cases

World Health Organization officials said Wednesday that preliminary data suggest that the Omicron variant — which has been reported in 57 countries — presents a rapid increase in transmission but causes milder cases of COVID-19 than the Delta variant, which is still spreading across the globe.


Although the emerging data is a cause for relief, WHO Director General Tedros Adhanom Ghebreyesus said it is too early to draw conclusions and that more data and time is needed to have a complete picture of the risks and impact of the variant.

Given Omicron’s virulence and high number of mutations, Thedros said it is undeniable that it “could have a mayor impact in the course of the pandemic,” urging countries to keep their guard up, accelerate vaccine access, and ramp up efforts to keep transmissions down.

“The steps countries take today and in the coming weeks will determine how Omicron unfolds,” Thedros said. “Complacency could cost lives.”

Some studies — including one in South Africa — found that Omicron partially evades protection of the Pfizer/BioNTech vaccine, but WHO scientists warned Wednesday that these preliminary results were drawn from a small number of samples and have not been peer-reviewed.

They emphasized that the significant drop in the level of antibodies found in some of the samples doesn’t necessarily translate into a reduction in vaccine efficacy.

“It is premature to conclude that this reduction in neutralizing activity would result in a significant reduction of vaccine effectiveness,” Soumya Swaminathan, WHO’s chief scientist said. “We do not know that.”

WHO officials contend that vaccines produce a wide-ranging immune response, with levels of antibodies being only one element of it, and said these experiments offer an incomplete picture on the efficacy against severe disease or death from Omicron.


Washington Post

US hospitalizations rising as 4 states see surges

COVID-19 hospitalizations are rising in the United States, driven by surges in four states that represent nearly half the increase nationwide.

Overall, the seven-day average number of people hospitalized with COVID-19 has risen by nearly 12,000, or 29 percent, since Nov. 10, when about 40,000 COVID patients were hospitalized, according to the Centers for Disease Control and Prevention. On Dec. 5, an average of about 52,000 were hospitalized.

During that time frame, Michigan’s COVID hospitalizations rose by nearly 1,900, CDC data show, marking the highest figure for a single state. Hospitalizations also went up by more than 1,400 patients each in Ohio and Pennsylvania and by more than 900 in Indiana. The four states, which have some of the highest per capita current hospitalization numbers in the United States, are responsible for almost half of the country’s increase in COVID hospitalizations between Nov. 10 and Dec. 5.

Coronavirus cases, driven by the Delta variant, have also been rising since late October. A rise in hospitalizations tends to follow a rise in new cases by a couple of weeks. At the pandemic’s peak in January, US hospitalizations reached nearly 128,000.

Washington Post

Variant fears fueling muted or canceled holiday celebrations

With the Omicron virus variant sowing a new wave of uncertainty, leaders around the world are opting to have 2021 rung out the way it was rung in, with only muted public celebrations or none at all.


From Brazil to Germany to the United States and beyond, local officials have canceled Christmas and New Year’s Eve events. The beaches of Copacabana will be empty because officials in Rio de Janeiro have canceled the city’s famous New Year’s Eve celebration. Mayor Eduardo Paes, Rio’s mayor, said on Twitter on Saturday that the event would not take place because, “We respect science.”

In Germany, the popular Christmas markets in Munich, Dresden, and other cities did not open this year. Officials in Baltimore called off a New Year’s Eve fireworks show and said in a statement to WBAL-TV that the city hoped to bring the event back next year.

The state of Odisha in eastern India issued an order last week banning New Year’s Eve and New Year’s Day celebrations because of the “large potential for spread of Covid-19 infections.”

Taking a different tack, New York City plans to allow fully vaccinated people to throng Times Square in traditional fashion to watch the ball drop on New Year’s Eve, Mayor Bill de Blasio said last month.

New York Times