Im not sure if you can help with this. But I have questions…

Do you want the father to have 50% custody?

You may need to apply to the courts to set a custody arrangement. You can force the father to continue to have the 50% custody (as they are the legal guardian and is legally responsible for the child during that time) and still get the child to get vaccinated. You are going to have a problem if there is no formal order because nothing is decided.

I would agree with you, but normally in situations like this, parents apply to remove custody from the father to stop them from making decisions for the child, but you do not want to do that because you actually need his help.

If you do not care whether he is in the child's life, apply for the court to get full custody, force him to pay child support and get your kids vaccinated.

I wish I have a better answer for you, but the only real option is to apply to the court to only give him visitation and no custody rights (rights to affect the children's decision). However, if he straight up abandons the children, there is not much you can do about it.

Ok first and foremost :

“Custody” means the legal ability and responsibility to make major decisions for a child’s care and upbringing such as:

where they will live;

where they will go to school;

what medical treatment they will receive; and

what religion they will practise.

You might need a custody order if:

You are not living with your child’s other parent and have not been able to negotiate or mediate custody or access arrangements; or

You are looking after a child whose parents have died or are unavailable, unable or unwilling to care for him or her.

What does access mean?

If the child lives with one parent, the other parent usually has a right to have contact with the child. In most cases, the parent who does not have custody spends time with the child. This is called visitation or access.

This is what you want correct?

Yes, I will give you that now, I just wanted to make sure I understand you.

You need to start a claim for custody:

Form 8: Application (genera)

Form 35.1: affidavit in support of claim for custody or access.

Here is the self-help guide: https://www.attorneygeneral.jus.gov.on.ca/english/family/guides/Parenting_Affidavit_Self-Help_Guide-EN.html

You will need to serve the father, then file with the court

You do not need a lawyer, but it is always recommended.

Yes, then they will be able to help you with everything. Retain a family lawyer.

You are welcome. Is there anthing else I can help you with today?