First COVID-19 vaccines 'may not be perfect', says head of UK vaccine task force

Bingham added that the first vaccines would be available in the UK this year if the injections proved "safe and effective".

Speaking on BBC television, Bingham said: "If the first two vaccines, or two of them, show that they are both safe and effective, I think it's possible that the vaccines will be available from Christmas Day."

She added: "Otherwise, I think it will be set for early next year as a reality."

To date, the Vaccine Working Group has secured six potential COVID-19 vaccines, including candidates from AstraZeneca and Oxford University, Pfizer and BioNTech, Janssen, Novartis, GlaxoSmithKline, Sanofi and Varneva.

The most advanced of these candidates are based on novel formats, such as Pfizer/BioNTech's mRNA-based candidate BNT162b2.

If these candidates prove to be effective in large-scale Phase 3 trials, the UK Vaccine Taskforce could choose to purchase sufficient doses of each vaccine to manage the "appropriate" UK population.

Despite encouraging preliminary data from early trials of the first vaccine candidates, Bingham urged against excessive "over-optimism".

She added: "The first generation of vaccines are likely to be imperfect and we should be prepared for them not to prevent infection but to reduce symptoms, and even then they may not apply to all or in the long term."

Pfizer expects the first efficacy data from its BNT162b2 Phase 3 trial to be available, with chief executive Albert Bourla revealing in an open letter published last week that the company will submit the vaccine for emergency use authorization in the U.S. by the third week of November.