It's understood child protection workers receive relatively few notifications about unvaccinated children. Whooping cough, the common name for pertussis, is a highly contagious infection that kills one in 200 infected babies. Babies younger than six months are particularly at risk of complications, and babies younger than three months can stop breathing during a coughing spasm. Pertussis rates have soared in Victoria, with 4519 confirmed and probable cases so far this year, compared with 4244 cases for the same time in 2014 and 2759 cases for the same time in 2013. At the end of last year, 1.77 per cent of Victorian children were registered as having a "conscientious objection" recorded against them being immunised, compared with just 0.23 per cent in 1999. The woman, who Fairfax has chosen not to name, told the anti-vaccination group she brought her then-10-week old baby in for a routine health check last Friday.

The nurse, alarmed that the baby had flu-like symptoms and could be contagious, sent the woman home. Despite the woman's protestations she was already in touch with her GP and claims she could not have the girl immunised because she was already sick, the nurse called child protection authorities to report the case. The woman said child protection authorities called her, but took no further action after she told them she had been talking to her GP about her baby's care. She added that her GP had "told the department off" for calling the woman, and advised her not to return to the maternal health nurse. It's understood child protection workers receive relatively few notifications about unvaccinated children. But on Thursday, the woman posted an update to say her baby had been rushed to emergency at Monash hospital the night before after "a very scary episode" in which mucus caught in her throat. The baby was kept in hospital for two nights, and medical staff urged the woman to immunise her daughter when she left hospital, stressing that whooping cough could be fatal for babies.

The woman told supporters: "They [doctors] read me the riot act again but they believe me about doing vaccinations through the GP". Fellow anti-vaxxers unanimously supported the woman's decision, many debating the best form of homeopathy and vitamin C to give the child. One woman wrote: "Be gentle with yrself [sic]... You are tired and have been thru quite an ordeal. You know your facts. As far as vax goes u know more than those docs". Another wrote: "Whooping cough responds very well to high doses of vit c. My little one had it twice, made even scarier as she has chronic lung disease and was oxygen dependant at the time." The woman believes her older child caught the infection from an immunised child diagnosed with it at school. The government says there is growing evidence that immunity wanes over time.

A spokesman for Monash Medical Centre would not confirm how many whooping cough cases had been at the hospital this week "due to privacy". Since the Labor government reintroduced free vaccines for new parents on June 1, 67,030 whooping cough vaccine doses have been distributed to immunisation providers. Health Minister Jill Hennessy said: "The science on this is clear. Vaccinations save lives. It is completely irresponsible for people to ignore the science and choose not to vaccinate their child." Immunisations are free, and babies can receive their first immunisation from six weeks of age, with the second dose at four months. The mother has been contacted for comment.