Medical leaders are calling on anyone who is eligible to book a Covid-19 vaccine immediately.
The head of the NHS is also calling on people to make sure they attend their second vaccine appointments when called to do so.
People over 50 are able to book in for a vaccine with their GP, or using the vaccine booking website, while the clinically vulnerable and health workers can contact their GP to arrange an appointment.
April will see fewer available vaccines due to a slowdown in supply from India, with GPs told to concentrate on delivering second doses and vaccinating the over-50s and vulnerable groups.
‘Well on track’
NHS chief executive Sir Simon Stevens said: "We're well on track to meet our April 15 goal of offering NHS Covid vaccination to everyone aged 50 and over, as well as other high risk groups.
"In just the past two weeks, we've now jabbed nearly 85% of people aged 50-54, and over three million of the highest risk people have also now had their top-up second dose."
NHS medical director, Professor Stephen Powis, added: "Our fantastic staff, helped by local organisations and volunteers, have done everything in their power to jab millions of people at speed - an incredible achievement.
"As we start to see signs of normal life returning - seeing family or friends outdoors - protecting those most at risk is even more important.
"So, if you have not been jabbed and are eligible, please do book in - staff are working hard to protect as many as possible, as supply allows.
"I had my jab a few weeks ago - it is easy, quick and effective.”
More second doses
Yesterday marked the first day that more second doses of the Covid vaccine were administered in the UK.
More than 270,000 people received their second Covid jab yesterday, compared with 224,590 who received a second dose.
This means that a total of 30,905,538 have received at least one dose of vaccine, while 4,108,536 people have received both.