NHS workers will have to be vaccinated against COVID-19 in England from April, health secretary Sajid Javid confirmed on Tuesday in the House of Commons.
"I have concluded that all those working in the NHS and social care will have to be vaccinated," said Javid.
"We must avoid preventable harm and protect patients in the NHS, protect colleagues in the NHS and of course protect the NHS itself," he added.
He said there would be exemptions for people who do not have face-to-face contact with patients and for people who are medically exempt.
Nationally, 93% of NHS workers have received at least one dose of a COVID-19 vaccine but that the rate is as low as 84% in some trusts, the Department of Health and Social Care said.
There is already a requirement for people working in care homes to be vaccinated from November 11.
The decision to mandate vaccines for health workers came on the day the UK reported another 33,117 new cases and 262 deaths in the latest 24-hour period.
The United Kingdom has reported 142,000 deaths due to COVID-19, the second-highest total in Europe after Russia.
Some European countries including Italy and France had already made COVID-19 vaccines mandatory for health workers.