First, do no harm. That’s a good rule for all of us, not just doctors.

It would be a good rule for anti-vaxxers to pay far more attention to. Consider Marita Howell, who runs a daycare facility in Maroubra, in New South Wales.

Maroubra is one of the nine local areas in NSW identified by the National Health Performance Authority as being “at risk” of outbreaks because of vaccination rates of below 85 per cent.

And you know what else? Howell has a son, age 14, who had chemo for non-Hodgkin’s lymphoma. The chemo destroyed his immune system. He was too sick for school, so he was recuperating at the daycare facility. And oh whoops, two unvaccinated children fuelled an outbreak of chicken pox at that facility.

Westmead Children’s Hospital paediatric oncologist Luciano Dalla-Pozza compares non-vaccination to drink-driving in terms of the danger it presents to cancer patients, whose immune systems are devastated by chemotherapy.

“We’ve had deaths (of cancer patients) from measles and chicken pox because it gets in the lungs and causes severe pneumonia,” Dr Dalla-Pozza said. “If you come into contact with kids on chemo, you put someone else’s life at risk.”

Ms Howell was terrified when the chicken pox outbreak swept her centre. “If you don’t immunise your child, for people like Jonathon that can be life-threatening. The thing that kills kids is not the cancer, but the infections they pick up,” she said.

By law, she can’t exclude the unvaccinated children.

What.a.mess.