Covid booster shots significantly strengthen immunity, trial finds

Jabs offer far higher protection than that needed to prevent hospitalisation and death, Cov-Boost trial lead saysThe findings show that both Pfizer and Moderna mRNA vaccines are highly effective boosters.

The findings show that both Pfizer and Moderna mRNA vaccines are highly effective boosters. Photograph: Leon Neal/Getty Images

Covid booster shots can d

ramatically strengthen the body’s immune defences, according to a study that raises hopes of preventing another wave of severe disease driven by the Omicron variant.

In a study published in the Lancet, researchers on the UK-based Cov-Boost trial measured immune responses in nearly 3,000 people who received one of seven Covid-19 boosters or a control jab two to three months after their second dose of either AstraZeneca or Pfizer vaccine.

Those boosted with Pfizer after two doses of AstraZeneca had antibody levels a month later nearly 25 times higher than controls. When the Pfizer booster was given following two Pfizer shots, antibody levels rose more than eightfold.

The most potent booster in the study was a full dose of the Moderna vaccine, which raised antibody levels 32-fold in the AstraZeneca group and 11-fold in the Pfizer group. When Moderna is used in the UK booster programme, it is given at a half-dose.

While the findings show that both Pfizer and Moderna mRNA vaccines are highly effective boosters, scientists cautioned about comparing their performance as people started with different antibody levels. For example, antibody levels tend to remain high a few months after a Pfizer vaccination, so a booster would not be able to drive them much higher.

“These are remarkably effective immunological boosters, way above what is needed to prevent hospitalisation and death,” said Prof Saul Faust, the trial lead and director of the NIHR clinical research facility at University Hospital Southampton NHS Foundation Trust. While side-effects varied, most people who reported them had fatigue, headache or arm pain and the study found no safety concerns.

Beyond antibodies, the scientists looked at the impact of boosters on T-cells – another crucial component of the immune system linked with the prevention of severe disease. Most of the boosters, including Pfizer, Moderna and AstraZeneca, increased T-cell levels regardless of the vaccine people had for their first two doses.

One result that has caught scientists’ attention is that the T-cell response was as good against the Beta and Delta variants of concern as against the original virus that emerged from Wuhan. Asked if the finding might be relevant to the Omicron variant, Faust said: “Our hope as scientists is that protection against hospitalisation and death will remain intact.”

Jonathan Ball, professor of molecular virology at the University of Nottingham, who was not involved in the study, shared Faust’s optimism.

“Whilst variants, such as the Delta variant, reduced the overall virus-killing effect of antibodies, the T-cell responses were pretty much unaffected,” he said. “The fact that the mRNA vaccine boosts gave a marked increase in both antibodies and T-cells is great news, especially now, when our attention has been grabbed by the emergence of the Omicron variant.

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“We still don’t know how this increase in immunity translates into protection, especially against serious disease, but I am still convinced that our vaccines will continue to provide the protection that we need.”

Early results from the Cov-Boost study underpinned the decision by the Joint Committee on Vaccination and Immunisation to shorten the time people had to wait for a booster from six to three months. The study found AstraZeneca to be an effective booster too, raising antibody levels three and five times after primary vaccination with AstraZeneca and Pfizer respectively.

Further results from the study suggest that booster programmes could switch to half-doses of the Pfizer vaccine without losing much protection. The data shows that half-doses of Pfizer boosted antibody levels in the AstraZeneca group nearly 17 times and more than six times in those who had Pfizer for their first two shots.


Biden Lays Out Winter Covid Game Plan

President Biden has laid out a multi-pronged plan to confront the delta and emerging omicron variants of the coronavirus that includes an expansion of at-home diagnostic tests, stricter testing rules for international travelers and new efforts to encourage vaccines and boosters.

During a speech at the National Institutes of Health, the president also sought to brace the public for a rise in COVID-19 cases this winter, urging those eligible to get their vaccine booster shots even as he showed optimism about the country’s continued efforts against the virus.

“My plan I am announcing today pulls no punches in the fight against COVID-19 and it’s a plan that I think should unite us,” Biden said. “I know COVID-19 has been very divisive in this country. It’s become a political issue, which is a sad, sad, commentary. It shouldn’t be.”

Biden reiterated that the new variant is “cause for concern but not panic” and pledged to fight it “with science and speed, not chaos and confusion.”

The Biden administration early next week will put in motion a new policy for international travelers to test negative for COVID-19 within 24 hours of boarding flights to the U.S., rather than the current policy of within three days.

The administration has held off on implementing vaccine or testing requirements for domestic flights, though officials maintain that it and other steps are not “off the table.”

The Transportation Security Administration is also extending its mask mandate for flights, trains and public transit until March 18.

As part of Biden’s plan, the administration will also move to allow Americans with private health insurance to seek reimbursement for at-home COVID-19 diagnostic tests. The Departments of Health and Human Services, Labor and the Treasury will issue guidance by Jan. 15 on the new rule.

White House press secretary Jen Psaki told reporters that additional details would be available in January that will shed light on when Americans can expect to get reimbursed for the tests and whether the costs would ultimately be covered by the government or the insurers.

The White House is also launching hundreds of family vaccination clinics and rolling out a new public education campaign to reach seniors who haven’t gotten their booster shots, as part of an effort to increase the uptake of vaccinations and booster shots.

In his Thursday speech, Biden called on private companies to offer workers paid time off so they can get their booster dose.

The new measures come as Biden’s vaccine mandates for private companies and healthcare workers have been stalled amid legal challenges.

“While my existing federal vaccination requirements are being reviewed by the courts, this plan does not expand or add to those mandates,” Biden said, calling it “a plan that all Americans can hopefully rally around.”

Despite his plea for unity, neither the emergence of the omicron variant nor the new White House steps to address it have shown signs of unifying the country. There are partisan divides on masks and vaccinations and Republicans have attacked Biden over his vaccine mandate for businesses.

Two cases of omicron had been detected in the U.S. — one in California and the other in Minnesota — at the time of Biden’s speech. A third was disclosed in Colorado shortly thereafter. While little is known about the new variant, first identified in southern Africa, health experts believe it has the potential to be more transmissible and that the vaccines could offer less protection against it.


US confirms at least three omicron cases

© (Associated Press photo/David Zalubowski)

Minnesota and Colorado confirmed the country’s second and third COVID-19 cases involving the omicron strain, one day after the Centers for Disease Control and Prevention (CDC) identified the first in California.

The second was detected in someone from Minnesota, whose only recent travel had been to a convention in New York City. He developed symptoms on Nov. 22, a full week before the travel ban took effect, an indicator that the strain was already circulating in the U.S.

The third was found in Colorado, in a person who traveled throughout Africa and returned to the U.S. late last week.

All three individuals were fully vaccinated and endured only mild symptoms.

“While this is clearly something to take seriously … it is not a reason to panic,” Minnesota Health Commissioner Jan Malcolm said during a press conference.

Though no cases of omicron have been confirmed in New York, New York City Mayor Bill de Blasio (D) said on Thursday that people should assume the variant is already present in the city.

Important to note: Since omicron’s emergence, health experts have stated that it is still unclear how well the strain evades immunity offered by currently available COVID-19 vaccines. Numerous vaccine developers have hypothesized that oral COVID-19 treatments and booster shots should be effective against the variant.


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People pull shopping carts as they walk past an information board, amid the outbreak of the coronavirus disease (COVID-19), in Bolton, Britain, June 16, 2021. REUTERS/Phil Noble

Omicron marches on as Biden prepares U.S. for grim winter

Australia, despite restrictions on international visitors, became the latest country on Friday to report community transmission of Omicron, a day after the coronavirus variant was found locally in five U.S. states.

U.S. President Joe Biden warned on Thursday that infections will rise during the northern-hemisphere winter and the European Union’s public health agency said Omicron could account for more than half of all infections in Europe within months. read more

New U.S. international travel testing rules take effect Monday

New rules requiring international air travellers arriving in the United States to obtain a negative COVID-19 test within one day of travel will take effect Monday at 12:01 a.m. ET (0501 GMT), according to an order issued late Thursday.

The administration is considering whether to grant temporary exemptions for about two dozen countries where access to same-day testing is limited, but the details are still being finalized, the sources added. Those exemptions could last for only about a week and are expected to be detailed on Friday. read more

Novavax says it could start making Omicron-specific vaccine in January

Novavax Inc said on Thursday it could begin commercial manufacturing of a COVID-19 vaccine tailored for the Omicron coronavirus variant in January next year, while it tests whether or not its current vaccine works against the variant.

Laboratory data expected in the coming weeks will show whether antibodies from individuals who have previously received Novavax’s COVID-19 shot can neutralize the variant, according to the company. Novavax also said it has started developing an Omicron-specific spike protein antigen and will begin laboratory tests of a new vaccine to target the variant in a few weeks. read more

China easing rules for US business travellers, approvals in 10 days

China will cut to no more than 10 days the time required for approval of travel by U.S. business executives, its ambassador to the United States said on Thursday, promising to turn “an attentive ear” to concerns raised by businesses.

Qin Gang, who arrived in the United States in July, told a dinner hosted by the US-China Business Council that Beijing would also work to make COVID-19 testing more convenient and allow executives to work during quarantine. Qin said Beijing would share its specific workplan “very soon” with the U.S. Centers for Disease Control. read more

Nightclubs, cafes and casinos reopen in Auckland

Aucklanders returned to nightclubs, cinemas and cafes on Friday as New Zealand’s biggest city exited pandemic lockdown after more than 100 days. Retailers threw open their doors to vaccinated customers as the country ended lockdowns and moved into a new ‘traffic light system’ that rates regions as red, orange or green depending on their level of exposure to COVID-19 and vaccination rates.

Auckland, the epicentre of the country’s Delta outbreak, will start at red, making face masks mandatory and putting limits on gatherings in public places. Bars, nightclubs and restaurants can open to guests with vaccine certificates but with a limit of 100 people and 1 metre social distancing. Outdoor events are allowed. read more

UK study finds mRNA vaccines provide biggest booster impact

COVID-19 vaccines made by Pfizer and Moderna that use mRNA technology provide the biggest boost to antibody levels when given 10-12 weeks after the second dose, a British study published on Thursday has found.

When AstraZeneca, Novavax, Johnson & Johnson and Curevac were given as boosters, they increased antibody levels for either initial vaccine, albeit to a smaller degree. However, while Valneva boosted antibodies in people initially vaccinated with AstraZeneca, it did not provide a boost for Pfizer. The study found that booster shots also helped to generate a broad T-cell response against the Beta and Delta variants, which may play a key role in longer-term protection. read more

Compiled by Karishma Singh; Editing by Kim Coghill


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