Staff at the Royal Free played a key role in a Covid-19 vaccine study which found that a single dose can significantly boost how protected someone is against new variants of the virus.

If someone has already had mild or asymptomatic Covid, then research on NHS workers - including 200 at the Royal Free - showed a single dose of the Pfizer/BioNTech vaccine conveys "significantly enhanced" protection against the coronavirus - including the variants first identified in Kent and South Africa.

The immune systems of those who had not previously had Covid-19 responded less strongly to the first dose of the vaccine - highlighting the importance of second doses in fully protecting people.

The research, led by scientists at UCL, Queen Mary University and Imperial, has been published in the journal Science.

Professor Marianna Fontana, principal investigator on the study for the Royal Free, said: “This significant study highlights the importance of completing your two doses of the vaccination to provide greater protection.

"This study is also an incredible example of scientific collaboration between hospitals, universities and departments. Each has provided a valuable contribution."

She thanked volunteers for their participation.