NHS England will launch its Covid booster programme on 5 September, officials have said, as the UK prepares to becomes the world’s first healthcare system to offer a next-generation vaccine that targets both the original strain of the virus and the Omicron variant.

More than 26 million people will be eligible for another Covid-19 jab over the next few months, with health officials hoping a second national booster programme will lessen the risk of both coronavirus and flu cases overwhelming already overstretched hospitals this winter.

Steve Russell, the national director for vaccinations and screening, said: “This winter will be the first time we see the real effects of both Covid and flu in full circulation as we go about life as normal – and so it is vital that those most susceptible to serious illness from these viruses come forward for the latest jab in order to protect themselves.”

The health service is engulfed in one of the worst summer crises in decades, especially in urgent and emergency care, with some elderly patients waiting hours for an ambulance and even longer to be admitted to a hospital ward.

The autumn booster campaign is among a package of NHS measures to prepare for winter, including increasing bed capacity and the number of 999 and NHS 111 staff to deal with any additional pressure.

NHS England said care home residents and housebound people would be among the first to be vaccinated when the scheme began on 5 September. A wider programme would start on 12 September. The other UK nations are organising their own schedules.

The UK is the first country in the world to approve Moderna’s bivalent vaccine – which targets the original Covid strain and the Omicron variant BA.1 – but there remain concerns there will not be enough doses to offer the new jab to everyone eligible.

NHS England said people would be offered the bivalent vaccine where appropriate, and subject to sufficient supply. It said the original vaccines continued to provide good protection, and urged people to take the jab when offered.

As with previous campaigns, the oldest and most vulnerable people would be called first, with people able to book online or through 119, as long as it had been three months since their last dose. Up to 3,000 sites were expected to be part of the programme, including GP practices and community pharmacies, and new venues may be added.

“The NHS was the first healthcare system in the world to deliver a Covid-19 vaccine outside of clinical trials, and will now be the first to deliver the new, variant-busting vaccine when the rollout begins at the start of September,” said the NHS England chief executive, Amanda Pritchard.

She urged anyone invited for an autumn Covid booster and a flu jab “to do so as quickly as possible – it will give you maximum protection this winter”.

NHS England will be offering the flu vaccine from 1 September, and, if eligible, people can have it at the same time as the Covid one.

The national booking service is expected to open during the week of 5 September, with people most susceptible to serious illness from Covid-19 and those aged 75 and above invited to book an appointment from that week.

Health and social care staff will also be able to get the autumn booster. All providers are being asked to ensure their staff are offered the autumn jab, potentially alongside the flu jab. Everyone over 50 and carers over 16 are also among those eligible for the flu vaccine this winter.