If it helps, this is from the same article (here again: [0]) and sounds like you do not have to worry too much about this. All the best to you and your family!
"Can I reduce my child's risk of acute lymphoblastic leukaemia?
The evidence isn't well enough established to suggest definitive recommendations that will reduce risk of child leukaemia.
[...]
Obviously, parents make their decisions about childcare based on a number of factors. They should not worry that they are endangering their child by not sending them to a nursery or day care.
And while most childhood infections are benign, some less common ones bring their own set of serious risks. So this review certainly shouldn't be taken as an encouragement to ditch important methods of infection prevention, such as frequent handwashing and making sure your child's vaccinations are up to date."
"Can I reduce my child's risk of acute lymphoblastic leukaemia?
The evidence isn't well enough established to suggest definitive recommendations that will reduce risk of child leukaemia.
[...]
Obviously, parents make their decisions about childcare based on a number of factors. They should not worry that they are endangering their child by not sending them to a nursery or day care.
And while most childhood infections are benign, some less common ones bring their own set of serious risks. So this review certainly shouldn't be taken as an encouragement to ditch important methods of infection prevention, such as frequent handwashing and making sure your child's vaccinations are up to date."
[0] https://www.nhs.uk/news/cancer/child-leukaemia-linked-reduce...