Yvonne Doyle, medical director of Public Health England, defended the decision as â€œa reasonable scientific balance on the basis of both supply and also protecting the most people.â€ Researchers in Britain have begun collecting blood samples from newly vaccinated people in order to study how many antibodies they are producing at different intervals, from 3 weeks to 24 months, to get an answer to the question of what timing is best for the shots.
The doctorsâ€™ concerns came a day after government medical advisers said there was evidence that a new variant of the virus first identified in southeast England carries a greater risk of death than the original strain.
Chief Scientific Adviser Patrick Vallance said Friday â€œthat there is evidence that there is an increased risk for those who have the new variant,â€ which is also more transmissible than the original virus. He said the new strain might be about 30% more deadly, but stressed that â€œthe evidence is not yet strongâ€ and more research is needed.
Research by British scientists advising the government said although initial analyses suggested that the strain did not cause more severe disease, several more recent ones suggest it might. However, the number of deaths is relatively small, and fatality rates are affected by many things, including the care that patients get and their age and health, beyond having COVID-19.
Britain has recorded 97,329 deaths among people who tested positive, the highest confirmed virus toll in Europe and the fifth-highest in the world.
The U.K. is in a lockdown to try to slow the latest surge of the virus, and the government says an end to the restrictions will not come soon. Pubs, restaurants, gyms, entertainment venues and many shops are closed, and people are required to stay largely at home.
The British government is considering tightening quarantine requirements for people arriving from abroad. Already travelers must self-isolate for 10 days, but enforcement is patchy. Authorities are considering requiring arrivals to stay in quarantine hotels, a practice adopted in other countries including Australia.
â€œWe may need to go further to protect our borders,â€ Prime Minister Boris Johnson said Friday.