The campaign to change the rules was years in the making, orchestrated in part by two men with close ties to US health secretary RFK Jr

When a federal judge in Mississippi ordered a sweeping rollback of the state’s strict school vaccine rules in 2023, the ruling hit some doctors like “a gut punch”.

Mississippi had for years achieved some of the highest vaccination rates in the US for children – a point of pride in a place that consistently ranks at the bottom of other health measures.

The state health director warned of the dire possible consequences, including a comeback of preventable illnesses like measles, diphtheria and pertussis – known as whooping cough.

“None of these diseases are gone,” Dr Daniel Edney told a talk radio host as the state implemented the newly ordered rules. “They’ve not been eradicated. They’re just waiting. They’re lurking.”

The Guardian sent detailed questions to the US health department, Bigtree and Siri. Among the questions the Guardian asked was a request for each to comment on criticism that the Mississippi court case led to a surge in whooping cough cases, and ultimately the death of a baby. None responded directly to that claim.

“They see this as a victory. But I think pediatricians see it as an assault on our patients, and an assault on families,” said Dr Anita Henderson, a Hattiesburg pediatrician. Bigtree is “taking this situation to raise funds to do this in other states”.