Dr Hilary Jones has issued a stark warning to people ahead of the festive season.
Speaking on Good Morning Britain, the health expert urged people not to be “selfish” and reminded them of the sacrifices made by NHS staff this year.
He spoke amid fears that people were no longer being compliant with the latest lockdown restrictions.
Dr Hilary said: “But I want people to remember the fact 630 people – healthcare workers – sacrificed their lives in the first quarter of this year.
“They sacrificed their lives, picking up coronavirus from patients, fighting the pandemic. They worked in hospitals.
“Now if we forget what the NHS has done so far and we say to ourselves, OK, I’m going to take the risk and do what I want.
“To me, that is a selfish way of going forward.”
Dr Hilary added: “And I think we all have to remember, to me, that we are only going to get through this if we behave.
“If we socially distance, if we protect other people. That is the only way we go forward.”
Dr Hilary also warned that a vaccine was needed now “more than ever” after a study revealed the likelihood of reinfection.
Research by Imperial College London estimated just 4.4 per cent of adults had some form of immunity against Covid-19 in September, when cases began to increase again.
This is compared with 6 per cent found to have antibodies between June 20 and July 13, and 4.8 per cent between July 31 and August 31.
The study found that antibody levels fell by 26.5 per cent overall during the three-month period.
Experts said the data from the Real-Time Assessment of Community Transmission (React-2) study showed immunity was “waning quite rapidly”, which could lead to an increased risk of reinfection.
Good Morning Britain continues to air each weekday from 6am.