LONDON (Reuters) – The world faces about 4,000 variants of the virus that causes COVID-19, leading to a race to improve vaccines, Britain said on Thursday, when researchers began exploring the dose mix. of the Pfizer and AstraZeneca vaccines in an unprecedented world.
Thousands of variants have been documented as the virus mutates, including so-called British, South African and Brazilian variants, which appear to spread faster than others.
British vaccine distribution minister Nadhim Zahawi said it is very unlikely that current vaccines will not work against the new variants.
“It is very unlikely that the current vaccine will not be effective on variants, whether in Kent or other variants, especially when it comes to serious illness and hospitalization,” Zahawi told Sky News.
“All manufacturers, Pfizer-BioNTech, Moderna, Oxford-AstraZeneca and others, are looking for ways to improve their vaccines to ensure that we are ready for any variant – there are around 4,000 variants of COVID worldwide now.”
Although thousands of variants have emerged as the virus mutates in replication, only a small minority is likely to be important and change the virus appreciably, according to the British Medical Journal.
The so-called British variant, known as VUI-202012/01, has mutations, including a change in the spike protein that viruses use to bind to the human ACE2 receptor – meaning that it is probably easier to detect.
“We have the largest genome sequencing industry – we have about 50% of the global genome sequencing industry – and we are maintaining a library of all variants so that we are ready to respond – whether in the fall or after – to any challenge that the virus can present itself and produce the next vaccine, ”said Zahawi.
VACCINE RACE
The new coronavirus – known as SARS-CoV-2 – has killed 2.268 million people worldwide since it appeared in China in late 2019, according to Johns Hopkins University of Medicine.
Israel is currently far ahead of the rest of the world in vaccination per capita of the population, followed by the United Arab Emirates, the United Kingdom, Bahrain, the United States and then Spain, Italy and Germany.
Britain launched a test on Thursday to assess the immune responses generated if the doses of the Pfizer and AstraZeneca vaccines are combined in a two-dose schedule. Initial data on immune responses should be generated in June.
The study will examine the immune responses of an initial dose of the Pfizer vaccine followed by a boost of AstraZeneca, and vice versa, at intervals of four and 12 weeks.
The trial will be the first of its kind to combine an mRNA injection – one developed by Pfizer and BioNtech – and an adenovirus viral vector vaccine of the type developed by Oxford University and AstraZeneca. The injection of AstraZeneca is being tested separately in combination with another viral vector vaccine, the Russian Sputnik V.
The British researchers behind the study said data on vaccinating people with the two different types of vaccines can help to understand whether vaccines can be applied more flexibly around the world and may even boost immune responses.
Matthew Snape, an Oxford vaccinologist who is leading the study, said the mix of different vaccines proved to be effective in Ebola vaccine schemes and, although the test’s new combined vaccine technologies could also work.
“Ultimately, it all comes down to the same target – cells that make the spike protein – just using different platforms,” he told reporters.
“For this reason, we anticipate that we will generate a good immune response with these combinations.”
Public Health England chief of immunization Mary Ramsay said there were many precedents for this type of work, since vaccines against hepatitis A and B were interchangeable from two different manufacturers, and similar work was done for the human papillomavirus (HPV).
Reporting by Guy Faulconbridge, Andy Bruce and Alistair Smout, edited by Estelle Shirbon and Nick Macfie