“The country went into lockdown and now transmission has reduced a lot. We are vaccinating in multiple countries where there is high transmission, so we are increasing the chances of getting the results early.
“We can’t show the vaccine works unless we have infections in the groups that we know are being exposed and that the vaccine has protected them. With the transmission dropping so much in the UK, we now have trials going in Brazil and South Africa.”
Kate Bingham, the chairman of the UK Government Vaccine Taskforce, said that unless the Oxford vaccine was available sooner no other candidate looked capable of being ready this year.
She said it would be a “reasonable assumption” to think Britain would be facing the winter without a coronavirus vaccine.
Prof Gilbert added: “I hope we can improve upon those timelines and come to your rescue.”
But Sir John Bell, regius professor of medicine at Oxford, leading the vaccine development programme, also told the committee that the UK should be getting ready for a worst case scenario of a bad flu season combined with a second virus wave before a vaccine is ready.
The committee chairman, Greg Clark, asked whether Britain should prepare for a winter without a coronavirus vaccine or whether one might be ready in time.
Sir John said: “This whole epidemic has relied too heavily on assumptions that have turned out not to be true. So my strong advice is to be prepared for the worst. We will have a new set of other respiratory viruses floating and, if we happen to have a bad flu season, it will be a real challenge separating the flu from the Covid patients.”