An Auckland clinical director says unprecedented high demand for the measles vaccine has swamped GP practices and caused logistical problems for some.
Auckland has had 944 confirmed cases of measles so far this year, and the number is still on the rise.
Some GPs have spoken out angrily, notably in Papakura, about long waits and extra costs in getting more vaccines for their patients.
Health officials have stressed repeatedly that there is more than enough stock nationwide but nevertheless halted vaccine deliveries yesterday during a stock-take.
The Ministry of Health hasn't revealed what the stock-take has shown but said earlier yesterday it was needed to enable them to check stocks already distributed "to ensure we're making the best use of our vaccine supplies and to look at reallocating vaccine from areas of low demand to those with high demand".
Allan Moffitt, clinical director of the large ProCare network in Auckland, which covers 180 medical practices and 800,000 patients, said the outbreak has placed unprecedented demand on health services, including GPs.
"There's enough stock ... the issue is getting the stock to the right place, and particularly prioritising those practices where there are active cases of measles."
Dr Moffitt said several issues have confronted GPs, including the fact there are two different brands of the measles, or MMR, vaccine. He said one of these is no longer available.
It meant that if a practice had ordered that vaccine last week, they would be faced with having to resubmit the order.
He said that added to delays faced by some GP practices and the normal turnaround time for resupply stretched from two to three days.
Dr Moffitt said vaccine distributor ProPharma also faced a major job in getting vaccines to where they were most needed.
"There's many worried well people out there, rightly so, who may not have been vaccinated or not had measles and are under 50. Those people if they haven't had at least one MMR dose, need to have the vaccine. But we should prioritise those people that are more likely to be exposed to measles, such as South Auckland currently.
"The number of cases across the rest of Auckland is relatively low but we're certainly seeing huge numbers across Counties Manukau."
He said that unfortunately "the demand has swamped all practices. And so the public want the protection - and rightly so - and so that does create a logistical problem for the company in terms of making sure we've got enough urgent supply for those people that really need it quickly."
Some GP practices have said they are being charged $45 if they order vaccine re-supplies within the normal resupply period. They've said the charge should be waived, because it's a public health emergency, and because they lack cold-chain capacity to store large amounts of vaccine.
Dr Moffitt agreed it is a reasonable request to have the charge waived.
"This is not business as usual. This is a public emergency to some extent to try and prevent further cases ... measles and potentially people dying from it. So it is really important that we get timely delivery of vaccines."