- Experts say the theory is sound and, as with some other diseases, it could help convey effective immunity.
PARIS: French authorities are set to rule that under 55s who received a first injection of the AstraZeneca Covid-19 vaccine can be given a jab from a different producer for their second dose, Health Minister Olivier Veran said on Friday.
France's national health authority HAS last month said that the AstraZeneca vaccine should only be given to those aged 55 and over, due to the 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 Veran indicated that the HAS would change the advice.
"This will normally be confirmed today, it is totally logical," said Veran, with the HAS due to give a news conference at 0800 GMT.
France has been injecting health workers as a priority group in the vaccination drive, meaning that many younger people have already received the AstraZeneca jab due to their work.
As Veran noted, they included the minister himself, a neurologist aged 41, who was given the AstraZeneca vaccine live on television on February 8.
"It is completely consistent to say that we do not recommend the AstraZeneca vaccine to people under 55 years of age while we learn more," he said.
"Therefore, if you have received a first injection and are under 55 years old, you will be offered another vaccine 12 weeks after the first injection," he added.
Europe's medicines regulator said this week the AstraZeneca vaccine could cause very rare blood clots among some recipients, prompting several countries to to scale up restrictions on the jab.
There are several clinical trials underway looking at the efficacy of combining two types of coronavirus vaccine -- testing the technique known as heterologous prime-boosting.
Experts say the theory is sound and, as with some other diseases, it could help convey effective immunity.
"Based on previous studies which combine different vaccine types, a combination of the AZ and Pfizer vaccines is likely to be safe but it's important that this is tested in the context of a clinical vaccine trial," said Helen Fletcher, professor of Immunology at the London School of Hygiene and Tropical Medicine.