How to Protect 6-Month-Old from Varicella Exposure at School?

Hello, We have a kid 3.5 years old and 2 days back he and myself were exposed to Chicken Pox Virus (My kid's friend had boils on his body when we visited his house which they didn't know it was chicken pox), we both have not taken the chicken pox vaccination ever and never had chicken pox before can we take now the vaccination to prevent from chicken pox ? What is more concerning is we also had a premature baby 2 months back she and my wife are still in hospital and will be mostly discharged in 2 weeks we are terrified with the situation where our premature baby is vulnerable to this virus not sure what actions can we take.. Please suggest.

I'm currently in Vietnam and will be moving to Belgium in just over 2 months for my Master's studies. I’m planning to get the HPV vaccine (Gardasil 9), and I’d like to get 1 or 2 doses here in Vietnam, then complete the remaining dose(s) after I arrive in Belgium, as I don't have enough time to finish the 3-dose plan in Vietnam. Is this possible to do in Belgium? If yes, what should I prepare or bring with me (e.g., vaccination records, batch numbers, doctor's notes)? I’m a female over 18, and I will be paying out of pocket in both countries.

I am 21 years old and I would like to have an HPV vaccination as suggested from my gynecologist abroad, however idk how to do that in Belgium? Can GP order these vaccines for me? It is free of charge?

Do the boys over 9 years old need to have additional vaccines? If so, which ones and when? Thank you in advance