Is giving the polio vaccine to two children over the age of five, without the husband's knowledge and consent, considered a sin requiring expiation?

It is permissible to vaccinate the two children with a dose designated for those younger than them, provided that no harm results from it. The reference for determining harm is specialized doctors. As for disagreeing with the husband regarding vaccinating the children, the father is the guardian of the minor and responsible for him, and he has the right to consider his best interest, including his medical treatment. Therefore, the wife should have tried to convince her husband and sought help from specialists. The wife is required to repent from disobeying her husband in this matter and not to repeat such an act, and to supplicate extensively for his well-being.