Covid-19 boosters are to be offered to all vulnerable people and those aged over 50 six months after their second dose, Heath Secretary Sajid Javid confirmed this afternoon.
A plan B would be triggered if the NHS came under "unsustainable pressure", Javid added.
This would involve masks, potentially working from home and vaccine passports if needed.
Speaking to MPs, Javid said vaccinations were a fifth pillar of the government’s plan to tackle coronavirus and that 112,300 deaths, 143,600 hospitalisations and 24.7mln infections had been prevented so far by the current programme of jabs.
The UK has administered 92mln vaccine doses, data today revealed, with the jabs providing 95% protection against severe disease caused by coronavirus including the Delta variant.
Earlier, the Joint Committee on Vaccination and Immunisation (JVCI) said its preference for the booster jab was the Pfizer (NYSE:PFE) vaccine or alternatively a half-dose of Moderna's mRNA alternative.
Javid said that plan A for the government consisted of vaccines, including the first dose for 12-15 years and booster for the over-50s and vulnerable groups.
Other measures include test, trace and isolation with free PCR tests to continue: a £5.4bn payment to help the NHS with its Covid response; encouraging people still to meet outdoors and playing a key role in the international response.
Javid also urged people to have normal flu jabs because of the potential additional pressure on health services that an outbreak might cause.
Earlier, vaccines minister Nadhim Zahawi had said that a coronavirus-linked lockdown would be considered only as a last resort,
He added the government has more tools at its disposal now to tackle the pandemic this time and much more information about the virus than at the start of the first lockdown.
Test and trace, surveillance and the vaccine programme were not available at the start of pandemic he said, adding he was confident that the infrastructure is in place to deal with any new major outbreak.
Hospitalisations have been steadily rising during the summer, principally among those yet to be vaccinated, as the Delta variant of the virus has spread rapidly.
Shares showed little reaction to the news ahead of the PM’s update.
Pub, hotel and restaurant groups such as Whitbread, JD Wetherspoon and Mitchells and Butlers were all largely unchanged at 3,303p, 1,068p and 267p respectively.
Airlines, though, were weak even though the scrapping of the UK’s traffic light travel system and an end of PCR tests for fully vaccinated passengers are expected to be part of the PM’s speech.
Ryanair shed 1.3% to €15.70 and easyJet 0.6% to 586.2p.