Boris Johnson is set to publish a Covid blueprint to prepare for a “difficult time” this winter, with jabs for younger teenagers, a booster programme, flu shots and vaccine passports all expected to be part of the measures.

Johnson is likely to strike a more cautious note than he has done in recent months, warning the public to continue being careful as cases are rising – with more than 8,000 Covid patients in hospital in the UK despite the vaccination programme.

The government is looking to extend its emergency Covid powers – opposed by a caucus of anti-lockdown Tory MPs – in case restrictions are needed as a last resort.

No 10 is hoping the combination of measures to be announced next week will head off the need for further draconian lockdowns after some scientists warned that a “firebreak” could be needed this autumn.

The prime minister’s Covid plan for England is expected to coincide with announcements from the Joint Committee on Vaccinations and Immunisation (JCVI) on booster jabs and from the chief medical officers on the vaccination of schoolchildren aged 12-15.

The JCVI is understood to have agreed in principle to an autumn programme of booster jabs following lengthy discussions on Thursday, at which the panel was shown interim findings of the Cov-Boost study, which examined the efficacy of various vaccines given as a third dose to people who had previously had two AstraZeneca or Pfizer jabs.

However, it remains unclear how widespread a rollout of boosters was agreed, with government sources indicating they thought it would only apply to elderly or vulnerable people in the first instance.

The JCVI had already approved third injections for about 500,000 clinically very vulnerable adults and older children and it is possible it could simply extend this to people with other health conditions, or who are older.

It is also believed that the JCVI approved the idea of, where possible, booster jabs being given alongside the regular programme of annual flu vaccinations, which are also targeted at older people or those with health conditions.

Another study, known as ComFluCov, has been examining whether it is safe and effective to give both jabs together. While preliminary results in July suggested this was the case, there have been no updates since. But speaking in the Lords on Thursday, the junior health minister James Bethell said the two types of jab “will be co-administered”, indicating this is the government’s intention.

The UK’s four chief medical officers are also expected to give the go-ahead for children aged 12 to 15 to be offered Covid vaccines next week.

A week ago, the JCVI approved this for older children with serious health conditions, but said the evidence for doing so more widely was not sufficiently strong.

However, amid intense ministerial pressure to approve wider childhood vaccinations, the JCVI suggested the chief medical officers review the decision, taking into account wider factors outside its remit, such as the impact of vaccinations on disruption to schooling.