The Prime Minister particularly highlighted the risks that individuals vulnerable to coronavirus could get “seriously ill” even after being double-jabbed once the impact of the vaccine starts to wane.
He stressed that the current daily rates of cases, 43,467 on Friday in the UK, “do not currently constitute any reason” for the Government to impose Plan B which could see working from home, mandatory masks and vaccine passports.
However, ahead of talks at the G20 summit in Rome, Mr Johnson emphasised: “Rather than thinking new restrictions the best thing everybody can do is get that booster jab as soon as you’re offered it.
“It’s a very important message I think people don’t quite realise that the first two jabs do start to wane.
“So people who are double vaccinated can experience a waning effect in their immunity
“How sad how tragic it would be if people who had other complications other compromises in their health got seriously ill because they were overconfident about their level of immunity and didn’t get their booster when they needed it.
“So please please please can everybody get their boosters.”
Asked if he could guarantee a good Christmas, he added: “I see no evidence whatever to think that any kind of lockdown is on the cards.”
More than 1.6 million people who are newly eligible for a coronavirus booster vaccine will be invited to come forward next week.
Around 9.5 million booster invites have been sent to people in England so far, and more than six million jabs have been delivered in the first six weeks of the rollout, according to NHS England.
More than half of eligible people aged over 50 and over two thirds of people over 80 have received the third dose, the service said.
Eligible people include adults over 50, those living in care homes, frontline health and social care workers, adults with underlying health conditions which make them more vulnerable to coronavirus, and those they live with.
Deputy lead of the NHS vaccination programme, Dr Nikki Kanani, said the figures are “encouraging” and advised anyone who receives an invite to take up the offer.
She added: “It is encouraging to see that thanks to the efforts of NHS staff, millions of people have received their booster already and just over six weeks in, with over half of eligible over 50s already protected as we head into winter like no other.
“I’ve recently had my booster at a local pharmacy and with more people becoming eligible every day I would encourage anyone who receives their text or letter invite to book an appointment and get their potentially life-saving top-up jab as soon as they can.
“The vaccine is simple, quick and effective and will help us to give the country maximum protection from the virus.”
Overall, more than 86 million coronavirus doses have been delivered and nine in 10 adults have had their first dose since the rollout began in December 2020.
People who are eligible for boosters will be invited for the shot at least six months after their second dose, so the number of eligible people changes daily.
Text invites will come from “NHSvaccine” and will include a link to the NHS website, guiding people to their nearest vaccine site.