By Michelle Roberts
Digital health editor
From Monday, the NHS will take bookings from people in England wanting a free spring Covid booster vaccine.
Those eligible, including everyone aged 75 or older or with a weak immune system, can book via the NHS website, app or by calling 119.
Covid is now a relatively mild disease for the vast majority but can still be very dangerous and even life-threatening for some.
Vaccines lower the risk but protection fades, so top-up jabs are offered.
Who can have a free booster job?
Those eligible for a top-up shot at pharmacies and GP practices include:
- everyone aged 75 or older by 30 June 2024
- people in care homes for older adults
- anyone immunosuppressed who is aged six months or older
Some walk-in centres are also offering it.
The NHS is sending texts, emails, app messages or letters to those eligible - but they do not need to wait for the invitation to book.
UK Health Security Agency immunisations director Dr Mary Ramsay said: "With Covid-19 still circulating, it's important those at highest risk who are eligible for the spring vaccine get their jab to help top up their immunity.
"We are still seeing Covid-19 causing hospitalisations and severe illness, particularly among older people and those with weakened immune systems.
"And the vaccine provides the best protection - so don't put it off.
"If you're eligible, book your appointment as soon as you're invited by the NHS."
Which Covid vaccine is being used?
Several different vaccines are in use in the UK.
The boosters are Pfizer-BioNTech or Moderna messenger ribonucleic acid (mRNA) vaccines updated against more recent Covid variants.
Can people buy a Covid booster?
Some high street chemists and private clinics have started selling and administering Covid vaccines to people aged 12 and over, for about £45-£99.
A health professional speaks to each customer to check the booster is suitable.
The BBC spoke with Pharmadoctor, which assists the bookings with some pharmacies that offer the service.
Chief executive Graham Thomas told BBC News there had been big demand in the few weeks since the Pfizer vaccine went on sale, with more than 1,500 customers buying it at pharmacies his company works with.
Of them, 84% had no underlying medical conditions.
Many of the rest had conditions such as chronic lung or heart disease.
And 45 classed themselves as carers, looking after someone vulnerable.
A protein-based booster vaccine made by Novavax, which works in a more traditional way than the mRNA ones, should also be available to buy soon.
Moderna hopes to launch a combined flu and Covid vaccine in 2025.