Pacific Island vaccines losing their potency

By ANGELA GREGORY

Vaccines to protect Pacific Island children from killer diseases such as measles may be losing their potency because of poor storage.

Concerns about the "cold chain" storage of vaccines were raised at a combined Unicef and World Health Organisation meeting with health representatives of Pacific countries in Auckland this week.

The biggest fear is a re-emergence of measles in the countries that have been controlling the disease, which due to high mortality rates in Papua New Guinea, is the leading cause of child death in the Western Pacific.

At the meeting poor cold chain storage procedures were identified in Vanuatu.

This was put forward as a reason measles immunisation in Western Samoa was proving less effective than expected.

In Western Samoa last year a rubella outbreak threw up blood test results that showed immunisation rates for measles were less than had been expected from vaccination records.

Last July to October an outbreak of measles in the Marshall Islands, thought to have been triggered by an infected visitor, spread to 828 people.

Most were in the town of Majuro where 83 people were admitted to hospital, and two adults and a baby died.

The outbreak was controlled by limiting travel between islands, postponing the school term, and a major vaccination drive.

A Unicef spokeswoman, Gillian Mellsop, said there were concerns in the Pacific that some vaccines were not being stored at low temperatures.

In some instances they would be of no use when administered.

"There is possibly a breakdown in the cold chain storage."

Ms Mellsop said it was possible to check a vaccine's potency, but that might not always be happening.

She said vaccinations for the Pacific were sent from India and Indonesia to a central coolstore in Fiji.

They were then distributed to another 13 Pacific Islands, who were part of a vaccination independence initiative supported by New Zealand, Australia and Japan.

A problem was that the recipient countries then had to safely get the vaccines delivered to far-flung outer islands and atolls.

Unicef regional immunisation adviser Basil Rodriques said vaccination failure could in part explain why in Western Samoa the measles antibodies were not found in some blood samples.

He said an objective of the meeting was for the Pacific countries to share information about the problems they faced, like the need to improve their data collection and cold chain storage.

Overall most of the Pacific was doing very well compared with the rest of the developing world.

There was about 80 per cent immunisation coverage for the diseases for which free vaccinations were being offered, with a goal of 90 per cent.

The Ministry of Health in New Zealand says it is important to support and monitor vaccination levels in the Pacific because of the high level of movement between the countries.

Dr Clair Mills, manager of the ministry's national immunisation programme, said there was a firm commitment to helping.

"Preventable diseases don't recognise international boundaries - there is a lot of travel between the countries."

Dr Mills said that even in New Zealand there was poor data on immunisation, and a National Immunisation Register had been developed to roll out of South Auckland from July.

She estimated there was 85 per cent vaccination coverage in New Zealand but said 95 per cent was needed to eliminate measles transmissions.

"We are overdue for a measles outbreak, and there are still outbreaks of vaccine preventable diseases like whooping cough."

Other diseases like TB and rubella were also still active in the community.