An advisory group in the United Kingdom on Wednesday recommended that people under the age of 30 should be offered an alternative to the AstraZeneca coronavirus vaccine, reported BBC.

Wei Shen Lim, chair of Britain’s Joint Committee on Vaccination and Immunisation, said that the decision was taken “out of the utmost caution” rather than any serious concerns.

The move came after a review by Medicines and Healthcare products Regulatory, the UK’s drug regulator, showed that 79 people in the country had suffered rare blood clots after vaccination by March-end. Nineteen of them had died.

The regulator said it was not proof that the AstraZeneca vaccine had resulted in the clots but the link was getting firmer. Chief Executive of the drug regulator, Dr June Raine, said that the side-effects were “extremely rare” and that more work was needed to ascertain if the vaccine was causing the clots.

Raine said that the benefits of the Covid-19 jab outweighed the risks for the vast majority, reported Reuters. The chief executive, however, also said that the balance of benefits to risks was more “finely balanced” for the younger population.

Lim also echoed Raine’s views. He said that for younger people, where the risks of hospitalisation were much lower, the risk to benefit calculation of the AstraZeneca vaccine meant that others shots were preferable.

He, however, advised people to take the second shot if they have been administered the first AstraZeneca jab. Only those who suffered from the rare blood clots after the first dose should not get vaccinated, the drug regulator said.

Deputy Chief Medical Officer Jonathan Van-Tam said the decision would have a negligible impact on the speed of Britain’s vaccine rollout. “This is a vanishingly rare, but sadly quite serious, adverse event... and you can’t pick these kinds of things up until you have literally deployed tens of millions of doses of vaccine,” Van-Tam added.

Several countries had suspended the use of the AstraZeneca vaccine last month, but many of them later announced that they would resume it after the European medical regulator said the jab was “safe and effective”.

The vaccine is currently banned in Denmark, Latvia, The Netherlands and Norway. France, Germany, Finland, Lithuania, Sweden, Iceland and Spain have restricted it based on the age of the beneficiaries, according to BBC.

British Prime Minister Boris Johnson had also vouched for the safety of the vaccine. “That vaccine is safe and works extremely well, and now, only six months later, it is being made in multiple places from India to the US, as well as Britain, and it is being used around the world,” he had said.

On March 15, World Health Organization chief scientist Soumya Swaminathan said during a press briefing that no causal link had been established yet between blood clotting and the vaccine. However, some countries expressed doubts about the safety of the shot after several cases emerged of people developing blood clots or brain haemorrhages after inoculation.

AstraZeneca also said earlier in March that a safety review of people inoculated with its coronavirus vaccine had shown no evidence of increased risk of blood clots.

In India, the AstraZeneca-Oxford vaccine is one of the two vaccines approved for emergency use. Covaxin, developed by Bharat Biotech in collaboration with the Indian Council of Medical Research and the National Institute of Virology, is the other vaccine.