Pharmac, which took responsibility for the immunisation schedule from the Health Ministry last year, is also considering a vaccination against chickenpox. A spokesman said chickenpox and rotavirus vaccinations had been through a subcommittee and would go to Pharmac's main clinical advisory committee in May.
"We take that advice into consideration, combine it with an economic analysis, and prioritise that against other competing options we have with pharmaceuticals," he said.
The funding change means that Pharmac will now weigh the benefits of vaccinating all babies against common diseases up against funding expensive drugs that may benefit only a few people with rare diseases.
The Paediatric Society said hospitalisations for infectious diseases rose by 51 per cent in the 20 years to 2008, with the biggest increases in poorer areas where infections spread in overcrowded housing.
Diarrhoea and vomiting caused by stomach and intestine infections (gastroenteritis) was the most common medically preventable cause of acute hospital admissions in New Zealand children, and rotavirus accounted for 42 per cent of gastroenteritis admissions in children under 3 - between 300 and 400 hospital admissions a year. The World Health Organisation recommended vaccinating all babies against rotavirus in 2009 and Australia has included it in its free immunisation programme since 2007.
Rotavirus vaccines made by two drug companies, GlaxoSmithKline (GSK) and Merck, are both given to babies as liquid medicines, rather than by injections. Dr Best said doctors recommended one dose six weeks after birth and a second six to eight weeks later. GSK recently cut its price to $100 for a package of two doses, suggesting that the cost of vaccinating all 60,000 Kiwi babies would be around $6 million a year.
Chickenpox vaccines are given by a single injection to infants aged at least 9 months and are quoted by the Immunisation Advisory Centre at a price of $60-$90 a dose, suggesting a total cost for 60,000 infants of $3.6 million to $5.4 million.
Pharmac inherited a $30 million budget for immunisations from the Ministry of Health last year, but now weighs the value of vaccines against other drugs across its full budget of $760 million a year.
Australia has vaccinated all children against chickenpox since 2006 and an Adelaide University study reported yesterday that numbers of children hospitalised with chickenpox or shingles had dropped by 68 per cent since then.
Immunisation sceptic Hilary Butler said other overseas studies had found that breast milk was an effective protection against rotavirus.
Dr Best said breastfeeding did reduce the chances of infection but was not an absolute protection. "We certainly see breast-fed infants who still get rotavirus."
Stomach bug 'worse than anything else'
An acute case of rotavirus was "far worse than anything else" in the first seven years of life for Auckland twins Sam and Toby Marsh, their mother Sarah says.
The twins caught the bug five years ago, when they were 2, after going to a new play group.
"The next day they started vomiting," Mrs Marsh said.
Sam started first. "He was bending over, it was really hurting. Then 12 hours later the diarrhoea started, which was horrendous."
Toby started 24 hours after Sam and Mrs Marsh took them to her family doctor, who diagnosed rotavirus.
For the next six months they continued getting "crippled over with cramp" whenever they ate yoghurt, milk or certain fruits such as oranges.
"Compared with other things such as chickenpox, I think it was far worse," Mrs Marsh said.
"If I had known there was a vaccine I would definitely have given it to them, but in those days no one knew about it. It definitely was not discussed by my Plunket nurse or my GP."
