Omicron mutation could increase infectivity; EU cases top 1-mn mark

Study says that mutations in the variant can strengthen its affinity for human cells, evade antibodies

Mutations in Omicron can strengthen the affinity of the coronavirus variant for the human cells, which could increase its infectivity and evasion of antibodies, according to researchers.

Meanwhile,  Omicron has taken hold in the European Union, where daily cases of coronavirus exceeded 1 million on Wednesday for the first time since the start of the pandemic. Even though omicron symptoms are largely relatively mild, governments are still worried about pressure on hospitals and broader health services, and have stepped up measures—as well as the language—to force people to get vaccinated.

The scientists from Boston College in the US developed a computer model that can predict mutations in the SARS-CoV-2 virus, and provide insights into future variants of concern before they emerge.

The team used the model to develop an initial set of predictions about the role of mutations on infectivity and immune response evasion of Omicron and other SARS-CoV-2 variants with human host cells.

"We find that Omicron has not reached its full potential to bind human host cells," said Babak Momeni, Assistant Professor at Boston College.

“We identify mutations that can strengthen the virus affinity for the human cell, which could increase infectivity and evasion of antibodies," said Momeni, lead researcher on the project.

The Omicron variant of the coronavirus is suspected to be the most infectious yet by binding to human receptors better than the Delta variant.

The yet-to-be peer-reviewed research posted on a preprint repository found that Omicron may have the potential to continue to evolve even stronger binding to increase transmission and infectivity.

The spike protein of the coronavirus binds to a receptor on the host cells, called ACE2, which allows the virus to enter the cells and infect it.

Binding is the first step for infection, and several mutations in previous variants of concern have been shown to be important for increasing the spike's binding to human ACE2.

"We use a fully quantum mechanical model to theoretically assess how different mutations in the spike can contribute to its increased, or decreased, binding strength to human ACE2," said Momeni.

"The modelling shows that Omicron binds to receptor proteins stronger than the Delta variant," he said.

The model predicts what mutations allow better binding to host receptors and better evasion of antibodies, the researchers said.

Such mutations can potentially lead to a future variant of concern, they said.

"Having this knowledge from our model would help with readiness for detecting and preventing, as well as treating, emerging and future variants,” Momeni added.

He, however, cautioned that increased infectivity is only one important aspect in variants of concern.

It is also important to monitor the severity of symptoms and the ability of the variant to evade antibodies and vaccines, the researcher said.

The study found that Omicron's spike proteins bind better than the Delta variant to the human ACE2 receptor.

However, not all mutations in the spike protein's targeting system -- known as a receptor binding domain -- are beneficial for binding.

This suggests factors other than binding may also be involved in determining how the variant evolves.

One possible explanation is that the variant has acquired mutations to evade host antibodies, Momeni said.

Such mutations can be detrimental to its binding to the host receptor and were followed by additional compensatory mutations to recover, or even improve, its receptor binding.

Pfizer booster gets CDC panel’s backing for teens’ use

U.S. public health advisers said vaccinated teens should get a Covid-19 booster shot from Pfizer Inc. and BioNTech SE, an important step in efforts to expand immunizations and keep schools open.

The panel of outside experts convened by the Centers for Disease Control and Prevention voted to 13 to 1 to recommend the booster shot for people ages 12 to 17 who received their second dose at least five months earlier. CDC Director Rochelle Walensky endorsed the recommendation, making it official.

Brazil approves Covid vaccine for children aged 5-11

Brazilian health authorities authorized Covid-19 vaccines for children age five to 11 on Wednesday, as South America's most populous country faces a rapid increase in cases due to holiday gatherings and the arrival of the Omicron variant.

The final green light by Brazil's Ministry of Health comes three weeks after the nation's independent medicines regulator, Anvisa, declared Pfizer-BioNTech's child-size dose to be safe and effective.

"To all those parents who want to vaccinate their children, the Ministry of Health will guarantee doses of the (Covid) vaccine," said Health Minister Marcelo Queiroga in Brasilia.

Omicron pushes UK services PMI to 10-month low

Britain’s services sector grew in December at the slowest pace since the country was last in lockdown, as the spread of the Omicron variant of coronavirus hammered hospitality and travel, a survey showed on Thursday.

The IHS Markit/CIPS services Purchasing Managers’ Index (PMI) fell to a 10-month low of 53.6 in December from 58.5 in November, according to final data which was a fraction stronger than a preliminary ‘flash’ reading of 53.2.

The composite PMI, which includes Tuesday’s more upbeat manufacturing PMI, showed a similar move.

“Mass cancellations of bookings in response to the Omicron variant led to a slump in consumer spending on travel, leisure and entertainment,” IHS Markit economist Tim Moore said.

The last time the index was lower was in February 2020 when the economy was still under lockdown, and restaurants and non-essential shops were closed to the public, but December’s data was above the 50 mark that separates growth and contraction.

Unlike during the wave of Covid-19 cases last winter – when few Britons had been vaccinated—this year Prime Minister Boris Johnson has rejected new legal restrictions in England.

Omicron may be less severe, but not mild: WHO chief

The more infectious Omicron variant of Covid-19 appears to produce less severe disease than the globally dominant Delta strain, but should not be categorised as "mild", the head of the World Health Organization (WHO) said on Thursday.

Grammys 2022 rescheduled amid Covid spike

The organization behind the Grammys on Wednesday postponed the music awards gala scheduled for January 31 due to "uncertainty surrounding the Omicron variant" of Covid-19 that has ripped through the United States in recent weeks. "Holding the show on January 31 simply contains too many risks," a statement from the Recording Academy said, adding it would announce a rescheduled date "soon."

"The health and safety of those in our music community, the live audience, and the hundreds of people who work tirelessly to produce our show remains our top priority."

A class of pop stalwarts and newbies including Justin Bieber, Billie Eilish and Olivia Rodrigo were among the leading nominees for the 64th annual show, with Jon Batiste garnering the most nominations with 11.