The health secretary, Sajid Javid, called on millions of eligible people to come forward and get booster doses of the coronavirus vaccine, during a press conference on Wednesday.
What is the booster jab?
The coronavirus booster vaccine dose is designed to improve the protection people have received from getting the first two doses of the vaccine, and combat any waning efficiency.
Data from Public Health England (PHE) suggests that the protection provided by vaccines against severe illness gradually decreases over time.
The introduction of the third jab started on 20 September. On 15 October, the NHS said more than 3 million people had received it in the first four weeks.
But on 18 October, Jeremy Hunt, the former health secretary who now chairs the Commons health select committee, told the NHS England chief executive, Amanda Pritchard, that just 200,000 doses a day were being provided, half the 400,000 a day being given in the spring.
Who can get a Covid-19 booster vaccine?
Booster vaccine doses are on the NHS for people most at risk from Covid-19, who had a second dose of a vaccine at least six months ago.
A third jab has been offered to everyone over 50, as well as younger people with health conditions that put them at greater risk of getting very ill from Covid.
People should get the booster no earlier than six months after their second jab.
The following people are eligible for a booster jab:
People aged 50 and over
People who live and work in care homes
Frontline health and social care workers
People aged 16 and over with a health condition that puts them at high risk of getting seriously ill from Covid-19
People aged 16 and over who are a main carer for someone at high risk from Covid-19
People aged 16 and over who live with someone who is more likely to get infections (such as someone who has HIV, has had a transplant or is having certain treatments for cancer, lupus or rheumatoid arthritis)
People who are pregnant and in one of the eligible groups can also get a booster dose.
When can I get a booster jab?
Previously people were told to wait until they were notified by text, letter or by their GP before booking.
But on 21 October, the health minister Edward Argar said people no longer needed to wait to be invited to get their booster coronavirus vaccine if the right amount of time had passed.
“If you get to the six months plus one week, go on the national booking system and book yourself in,” he told Sky News.
What about children?
On 19 October, the government announced that from half-term, 12- to 15-year-olds in England would be able to get vaccinated at national hubs, rather than at school.
Children will also be allowed to go online and book an appointment in the same way as adults. Parents are being asked to wait for letters to arrive around the end of the week, asking for consent before signing up online.
It comes after criticism of the slow pace of the vaccine programme in teenagers: as of 19 October, 15% of 12- to 15-year-olds in England had been given one Pfizer jab, compared with 47% in Scotland.