At a Downing Street press briefing, Johnson said the concept of what constitutes “full vaccination” will need to be adjusted.
“On boosters, it’s very clear that getting three jabs—getting your booster—will become an important fact and it will make life easier for you in all sorts of ways, and we will have to adjust our concept of what constitutes a full vaccination to take account of that,” he said.
“As we can see from what’s happening, the two jabs sadly do start to wane, so we’ve got to be responsible and we’ve got to reflect that fact in the way we measure what constitutes full vaccination.”
Johnson said the government will be making plans to add the booster to the digital COVID-19 passport issued by the National Health Service.
The prime minister urged people to get the booster jab as soon as they are eligible. “It would be an utter tragedy if, after everything we have been through, people who had done the right thing by getting double vaccinated ended up becoming seriously ill or even losing their lives because they allowed their immunity to wane,” he said.
Earlier on Monday, the UK government accepted the advice from the Joint Committee on Vaccination and Immunisation (JCVI) to extend the booster vaccine programme to include people aged 40 to 49.
Health Secretary Sajid Javid said: “We know immunity to COVID-19 begins to wane after six months and new data published today shows a third dose boosts protection against symptomatic infection to more than 90 percent—this highlights just how important it is that everyone eligible gets their top-up jabs as soon as possible.”
Johnson told the Downing Street press conference there were “storm clouds” gathering over parts of Europe with a “new wave” of the CCP (Chinese Communist Party) virus sweeping through central Europe and now affecting Western Europe.
“We don’t yet know the extent to which this new wave will sweep up on our shores but history shows that we cannot afford to be complacent,” he said.
But Johnson said there was nothing in the data to suggest the country needed to move to the so-called Plan B, a backup strategy that involves measures such as vaccine passports and mandatory face coverings in public places.
PA contributed to this report.