French Prime Minister Jean Castex says France is investigating whether a fourth vaccination against the coronavirus can be given. Currently, France’s campaign for a third vaccination is in full swing.

“If the health authorities approve the fourth shot, we will go for it,” Castex said on Thursday. Israel is so far the only country to have approved a second booster for people with health risks.

Castex also said he is opposed to forced vaccination. “We are already having trouble checking the access passes; that will get even worse.” The French House of Commons approved the introduction of a vaccination pass on Thursday. Negative test certificates are therefore no longer valid for entering catering establishments, among other things.

The new vaccination certificate law is due to come into effect on January 15, but because it took three days for the lower house to approve the law, that date is in jeopardy. The Senate has yet to review the bill before it goes into effect.