US biotech company Novavax announced a 90.4 per cent efficacy rate for its Covid-19 vaccine, boosting hopes that a new vaccine could come on stream this year in the United States.
The results of the phase three clinical trial undertaken in the US and Mexico released on Monday also showed that the two-dose vaccine was similarly effective against newer coronavirus strains, especially the Alpha variant that originated in Kent, England.
Only one case of the highly contagious Delta strain, first detected in India, was found among trial participants, making the results on its effectiveness against this variant inconclusive.
US regulators are expected to approve the Novavax vaccine in the autumn. But with the US now dealing with an oversupply of vaccines amid slow take-up by some parts of the US population, it is possible the product will not be needed in the US.
The US was roundly criticised on social media on Monday after it emerged it had donated just 80 vials of the Pfizer vaccine to Trinidad and Tobago. The donation amounts to full vaccinations for just over 200 people in a country of 1.4 million.
In a statement, the US embassy in the Caribbean country said the US “believes that every vaccine counts”.
The Biden administration last week announced plans to buy 500 million Pfizer vaccines to donate to other countries through the World Health Organisation-backed Covax programme. It followed a previous commitment by the US to share up to 80 million vaccines around the world.
More than 64 per cent of the US population have received at least one dose of the Covid vaccine, while more than 54 per cent of adults are now full vaccinated. California became the latest state to lift restrictions, ending all social-distancing requirements indoors. Proof of vaccination or a negative test will be required for events of more than 5,000 people indoors.
However, the pace of vaccination rollout in the United States has slowed in recent weeks, with states offering a range of incentives – from beer to baseball tickets – to encourage people to get vaccinated.
Several Republican-controlled states have moved to outlaw so-called vaccine passports. Texas governor Greg Abbott signed an order prohibiting state agencies or state-funded entities requiring proof of Covid vaccination status.
But in a potentially significant ruling at the weekend, a court in Houston rejected a suit brought by a group of nurses at a Houston hospital challenging their employer’s requirement that they must be vaccinated.
The judge ruled that the Houston Methodist Hospital's decision to mandate vaccines was consistent with public policy and rejected claims by Jennifer Bridges, a nurse and the chief plaintiff in the case, that Covid vaccines were experimental and dangerous and that employees at the hospital were being treated like human "guinea pigs".
"The hospital's employees are not participants in a human trial," Judge Hughes wrote. "Methodist is trying to do their business of saving lives without giving them the Covid-19 virus. It is a choice made to keep staff, patients and their families safer."
He also criticised a comparison made by the plaintiffs between the vaccine requirement and medical experimentation during the Holocaust, calling it “reprehensible”.
As President Joe Biden continued his week-long trip to Europe, vice-president Kamala Harris flew to South Carolina to promote vaccine take-up. The stop in Greenville was the first in her so-called "vaccine tour" across the south.
Speaking to residents ahead of her visit to a vaccination centre at a YMCA, Harris said the vaccines had been developed over years of research as she encouraged people not to fear the jab. Vaccines could “save someone’s life,” she said.