Regulators in the UK have approved the use of Johnson & Johnson's single-shot coronavirus vaccine. The Medicines and Healthcare Products Regulatory Agency said that the drug met safety and quality standards. The decision makes it the fourth Covid-19 shot available in the UK. The Department of Health said the government had decided to order 20 million doses of the single-shot vaccine, also known as Janssen, amending an original order for 30 million doses. The vaccine will be available later this year. "As Janssen is a single-dose vaccine, it will play an important role in the months to come as we redouble our efforts to encourage everyone to get their jabs and potentially begin a booster programme later this year," Health Secretary Matt Hancock said. The drug is <a href="https://www.thenationalnews.com/uae/health/astrazeneca-vaccine-can-an-ingredient-in-the-injection-cause-blood-clots-1.1223025">already approved in the US</a> but its use was paused for 10 days after concerns over blood clots. The shot uses similar viral vector technology to the Oxford-AstraZeneca vaccine, which has also been linked to very rare blood-clotting incidents.