The world has about 4,000 variants of the virus that causes COVID-19, prompting a race to improve vaccines, Britain said on Thursday, as researchers began exploring the world’s first mixed doses of Pfizer and AstraZeneca injections.
Thousands of variants have been documented as mutated viruses, including the so-called British, South African and Brazilian variants which seems to be spreading faster than others.
British Vaccine Dissemination Minister Nadhim Zahawi hopes inoculation in order to be effective. “It is highly unlikely that the current vaccine will not be effective in either the Kent variant or the other variants, especially when it comes to severe disease and hospitalizations,” Zahawi told Sky News. “All the producers, Pfizer-BioNTech, Moderna, Oxford-AstraZeneca and others, are looking for ways to scale up their vaccines to ensure that we are ready for any variant. There are around 4,000 variants of COVID worldwide now.”
While thousands of variants have emerged as the virus mutates during replication, only a very small minority is likely to become important and transform the virus in any meaningful way, according to the British Medical Journal.
The so-called British variant, known as VUI-202012/01, has mutations that include spike protein changes which the virus uses to bind to human ACE2 receptors – meaning it may be easier to catch.
“We have the largest genome sequencing industry; we have about 50% of the world’s genome sequencing industry and we keep a library of all the variants so we are ready to respond – whether in fall or beyond – to whatever challenges a virus may emerge and produce the next vaccine,” said Zahawi.
The new coronavirus, known as SARS-CoV-2, has killed 2.26 million people worldwide since appearing in China in late 2019, according to Johns Hopkins University of Medicine.
Israel is currently far ahead of the world in terms of vaccinations per head of population, followed by the United Arab Emirates, Britain, Bahrain, the United States and then Spain, Italy and Germany.
The UK on Thursday launched a trial to assess the immune response that results when vaccine doses from Pfizer and AstraZeneca are combined in a two-shot schedule. Initial data on the immune response are expected to be produced sometime in June.
This trial will examine the immune response of the initial dose of Pfizer vaccine followed by the AstraZeneca booster, and vice versa, at intervals of four and 12 weeks.
The trial will be the first of its kind to combine an injection of mRNA – developed by Pfizer and BioNtech – and an adenovirus vector vaccine of a kind developed by the University of Oxford and AstraZeneca. The AstraZeneca injection has been piloted separately in combination with another viral vector vaccine, Sputnik V. Russia.
The British researchers behind the trial said the data on vaccinating people with two different types of vaccines could help to understand whether injections could be launched more flexibly around the world, and perhaps even boosted immune responses.
Matthew Snape, the Oxford vaccination expert who led the trial, said mixing different injections had proven effective in the Ebola vaccine schedule, and although the new trials used mixed vaccine technology, it could also work. “Ultimately, it all comes down to the same target – the cells that make the spike protein – just using a different platform,” he told reporters. “For that reason, we anticipate that we will generate a favorable immune response with this combination.”
UK head of Public Health immunization Mary Ramsay said there was a lot of precedent for the work, as vaccines for Hepatitis A and B were interchangeable from two different manufacturers, and similar work was being done on the human papillomavirus (HPV).