British researchers are to explore mixing doses of the Pfizer and AstraZeneca COVID-19 vaccines in a world first trial aimed at finding new ways to swiftly reduce coronavirus infections as new mutated variants emerge.<br /><br />While thousands of individual changes have arisen as the virus mutates on replication and evolves into new variants, only a tiny minority are likely to be important or change the virus in an appreciable way, according to the British Medical Journal.<br /><br />Among coronavirus variants currently most concerning for scientists and public health experts are the so-called British, South African and Brazilian variants, which appear to spread more swiftly than others.
