Parents have been cautioned to pay attention to the policies for private child vaccination packages, with the vast majority of programmes examined by the city's consumer watchdog requiring full payment in advance.

The Consumer Council on Monday also said that a number of healthcare service providers do not offer full refunds if a child is later deemed unfit for vaccination by a doctor.

It said parents who want to arrange vaccination not included under the government's programme should "consult a paediatrician or their own family doctor beforehand...and decide whether to let their children be vaccinated based on the doctor's assessment of their health and medical history".

The watchdog said it compared the service charges and information from 19 non-government subsidised vaccination schemes offered by a total of nine private healthcare facilities and medical groups, with prices between HK$3,000 and HK$14,680.

Eighteen of the schemes required consumers to prepay in full before the vaccinations, the council said, while only one service provider allowed payment by the dose and offered a seven-day cooling-off period.

Only three of the nine service providers explicitly stated that a consultation with their doctors over the vaccinations would cost extra.

"For the rest, even if a child is later deemed unfit for vaccination by a doctor, most service providers did not offer full refunds but required deductions for consultation fees or administrative charges, or only allowed consumers to switch to another scheme or transfer the scheme to another person within a specified period," the council said.

The watchdog also pointed to a lack of clarity relating to information from some service providers.

"One service provider displayed certain vaccines within a scheme in a different colour, but did not explain what the colour represents. Upon enquiry by council staff posing as consumers, it was revealed that those vaccines were not included in the package and required additional charges," it said.

"Another service provider only listed charges for individual vaccines on its website, and only provided scheme details via instant messaging after a phone enquiry, which was inconvenient for consumers and lacked transparency."