As Boris Johnson seeks to avoid a return to restrictions, or even another “firebreak” lockdown, this winter, we take a look at what might be in his “toolbox” of contingency measures for England expected to be announced as soon as next week – and just how useful they may be.

Children’s jabs

To jab, or not to jab, all 12- to 15-year-olds has become a matter of hot debate. Last week, the Joint Committee on Vaccination and Immunisation (JCVI) said it did not recommend the move, saying that while on balance it would bring health benefits, the margin was too small for it to give the green light. The matter is now being examined by the UK’s chief medical officers, who are considering wider factors including the potential impact of jabs on education, for example school closures.

Ministers are known to be extremely keen on this happening, with the assumption that the medical officers will give them the required approval.

Vaccinating this age group would reduce the chance of infection or severe illness, although the latter is already far lower than for adults, and could also help to reduce transmission. However, protection against infection is lower than for more severe illness, and Covid vaccines are somewhat less effective against the now-dominant Delta variant.

Booster jabs

Third jabs have been approved for about 500,000 people with severely weakened immune systems – but these are deemed to be part of their primary vaccination schedule rather than boosters per se.

The JCVI is considering whether a third Covid shot should be given more widely. While no decision is due until next week, there is a growing assumption that some sort of booster programme has been approved – though it may be limited initially to older and more vulnerable people. Ministers want it to happen, and have made plans for immediate distribution, possibly alongside flu jabs.

Some experts say booster jabs are not necessary, and that it would be unethical to give them when poorer countries have yet to vaccinate their populations.

But data from Israel, where a booster programme is under way with third jabs offered to over-40s, suggests there could be benefits. According to one recent study – yet to be peer-reviewed – seven to 13 days after the third dose the odds of becoming infected with Covid fell 48-68% compared with having two doses, while after 14 to 20 days the odds had fallen to 70-84%.

There are other factors to consider: take-up of second jabs has already levelled off in many age groups in the UK, and at lower levels than first doses. That, experts have said, could be owing to factors including a perception that a second dose is not necessary and that there is less incentive now society is returning to signs of normality.

One question is whether the uptake of a third dose may be even lower. However, some experts have said that is not a given, noting the longer a vaccine is shown to be safe, the more some people may be comfortable about taking it, and that at the very least roughly the same number may be expected to accept boosters as second doses.

Covid passports

Downing Street has said Covid passports will be introduced by the end of the month, making full vaccination a compulsory requirement for entry to nightclubs and other crowded indoor venues in England, without the option of showing a recent negative test or a positive antibody test. On Wednesday, Scotland voted for Covid passports to be introduced on 1 October.

In theory, the idea could help to reduce transmission of Covid, while it may also act as an incentive for people to get vaccinated. But it is a politically fraught area for Johnson, who could lose a Commons vote on such a move if Labour decided to oppose it – and if any such vote were held.

Critics also saythat even double-jabbed people can become infected with Covid, while for some the passports may make hesitant people even more reluctant to get jabbed. There are also concerns the plans could be an infringement of civil liberties and discriminatory.

Flu jabs

With very little flu in circulation last year, there is a big concern that people’s immunity to the virus is low, leading to fears that flu – together with other winter viruses and Covid– could put the NHS under extreme pressure.

Given that a key factor in whether new Covid restrictions are required is whether the NHS is becoming overwhelmed, keeping levels of flu down could be an important way to reduce the chance of that happening.

In July, ministers announced the introduction of the largest flu vaccination programme in UK history, with either a jab or nasal spray vaccine to be offered free to more than 35 million people. That will include all over-50s and secondary school pupils up to Year 11 as well as all children aged two and three, primary school pupils, people with certain health conditions, unpaid carers, pregnant women, close contacts of immunocompromised individuals, and frontline health and adult social care staff.

To save resources, experts have been looking at the viability of giving flu and Covid jabs at same time, dubbed the “one in each arm” autumn booster campaign. While an official announcement has yet to be made, the health minister Lord Bethell said on Thursday that Covid boosters would be given alongside flu jabs.