I’ve had every vaccine available including the one for meningococcal serogroup B, and I happen to know someone whose parents refused to vaccinate them for anything. We both lived in the same area and had the same level of social interaction.
My friend now suffers from chronic severe asthma due to a pertussis infection, in addition to cognitive impairment and deafness brought on by a meningococcal infection a couple of years after the pertussis infection. They’ve also had a bad case of influenza several times and they have had COVID-19 in recent years.
As others have stated, families shouldn’t be put at risk just because some people refuse to understand science.
The others have given great responses, but I thought I should mention that having a lifestraw could save your life. It filters the water as you’re using it, and it has saved lives in similar situations!