LONDON: People infected with COVID-19 are at a higher risk of developing the rare blood clotting known as cerebral venous thrombosis (CVT) than those who get a vaccine against the disease, a study published on Thursday by the University of Oxford, where the AstraZeneca vaccine was developed, said.

According to the findings, in the 500,000 virus patients studied, 39 in a million suffered from blood clots, with 30 per cent of cases found in those under the age of 30, while around five in a million cases were reported in patients who had had a first dose of the AstraZeneca/Oxford vaccine.

Among those who had received a vaccine other than AstraZeneca/Oxford - Pfizer or Moderna - the proportion was four in a million, researchers said.

"We've reached two important conclusions. Firstly, COVID-19 markedly increases the risk of CVT, adding to the list of blood clotting problems this infection causes. Secondly, the COVID-19 risk is higher than we see with the current vaccines, even for those under 30; something that should be taken into account when considering the balances between risks and benefits for vaccination," Sputnik quoted Paul Harrison, the head of the Translational Neurobiology Group at the University of Oxford, as saying in the press release.

John Bell, a professor of Medicine at the University of Oxford, also supported the findings of his colleagues, claiming that blood clotting events linked to vaccines are extremely rare.

"If you don't get a vaccine, you're going to get COVID, and if you get COVID you'll have a very, very much higher risk of getting a bad clotting problem," Bell told Sky News broadcaster.

Although the UK and the European Union medicine regulators have said that the benefits of having the AstraZeneca vaccine outweigh the risks, several countries have temporally suspended its application, while Denmark stopped its rollout completely.

In the United Kingdom, the regulator has advised that people under 30s should be rather offered a Pfizer/BioNTech or Moderna vaccine.

-- BERNAMA