France said under 55s who received a first injection of the AstraZeneca Covid-19 vaccine should be given a jab from a different producer for their second dose, a ruling affecting more than 500,000 people, according to AFP.

France's national health authority last month said the AstraZeneca vaccine should only be given to those aged 55 and over because of reports of potentially deadly blood clots in a very small number of those younger people vaccinated.

Officials in France initially said that those given the AstraZeneca jab in a first dose should go ahead with the second jab even if aged under 55.

But the health authoirty said that those aged under 55 who had been given the AstraZenaca as their first dose would now get the Pfizer-BioNTech or Moderna vaccine as their second course.