The immunisation rate for whooping cough in Australia has increased to at least 90% but the Royal Australian College of General Practitioners in Queensland warns that the vaccination does not provide life-long immunity to the virus and while most victims are more than one year of age, young infants are at greatest risk until they can have at least two doses of the vaccine, because their mother's antibodies do not provide reliable protection.

In adults whooping cough can manifest as a persistent cough, without the "whoop" but they nevertheless remain contagious for three weeks without antibiotic treatment, putting susceptible infants at greater risk of contracting the virus.

Experts say though an adult may only be mildly ill, they can pass on the nasty virus to a vulnerable newborn and any adult or child with a chronic persistent cough should visit their doctor.

The whooping cough vaccine is free as part of the National Immunisation Program Schedule for children aged two, four and six months - booster vaccinations are offered at four years and between 12 and 17 years through state governments - the vaccine is part of the combined diphtheria, tetanus and acellular pertussis shot (DTPa).