Janssen, a single-dose Covid vaccine, has been approved for use in the UK by the medicines regulator.
The vaccine, which was 85 percent effective in stopping severe illness from Covid-19 in trials, has met expected safety standards.
UK ordered 20 million doses that will arrive later this year. Janssen will be the fourth vaccine to be used in the UK to protect against Covid-19.
More than 38 million people have now received a first dose of a vaccine in the UK – nearly three-quarters of the adult population.
The vaccine is likely to be used to give care home residents a booster jab ahead of winter because it can be easily stored and transported at fridge temperatures.
The UK’s vaccine committee – the Joint Committee on Vaccination and Immunization (JCVI) – will produce advice on exactly who should receive the Belgian-made vaccine in due course.
The single-dose jab has already been authorized by the European Medicines Agency (EMA), the Food and Drug Administration (FDA) in the US and the World Health Organization (WHO).
Nadhim Zahawi, vaccine deployment minister, said: “The Janssen vaccine will be another weapon in our arsenal to beat this pandemic.
“We are doing everything we can to vaccinate all adults as quickly as possible and I encourage everybody to come forward for a jab as soon as they are eligible.”
The vaccine uses the same technology as the Oxford-AstraZeneca one and is likely to be more suitable for older adults than younger people. Under-40s are being offered an alternative to AstraZeneca in the UK because of a potential link to a type of rare blood clot in the brain.
The US, South Africa and the European Union briefly paused the rollout of the vaccine in April – also known as Johnson & Johnson – after reports of rare blood clots in very small numbers of people after their jab.
It is currently being tested as part of a UK study to find out whether a third dose could protect against new variants.