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By Fitri Wulandari and Ahmad Pathoni

JAKARTA , March 27 (Reuters) - Indonesia agreed on Tuesday to resume sending virus samples to the World Health Organisation after a breakthrough pact between the U.N. body and developing nations on access to bird flu and other influenza vaccines.

The agreement ended a stand-off between Jakarta and the WHO that began in December when Indonesia refused to share samples of the H5N1 avian influenza virus unless it had guarantees they would not be used commercially.

"We will share viruses again because WHO has made a strong commitment," Health Minister Siti Fadillah Supari told reporters.

"We have now agreed with WHO and other member states of WHO on a timetable to make the changes necessary to accomplish our objective of achieving equitable and affordable access to vaccines for developing countries around the world," she said.

Asked when Indonesia would start sending samples again to WHO, she said: "Immediately".

There are no commercially available vaccines for bird flu, though several companies are working to produce them.

Tuesday"e;s agreement, which came at the end of a two-day meeting between WHO and health officials from 18 nations, will be taken up at a ministerial meeting on Wednesday.

Indonesia has the world"e;s highest number of fatalities from bird flu, accounting for 66 of the 169 known deaths of people worldwide from the disease since 2003.

The health ministry said on Tuesday a teenager and a 22-year-old woman were also suspected to have died of H5N1.

The government had said the virus-sharing scheme under the WHO system did not guarantee poor countries access to influenza vaccines.

Jakarta had also said it wanted the WHO to help draw up "material transfer agreements" to control the use of samples.

Supari said delegates at the meeting had agreed to strengthen the global influenza surveillance network and improve access to safe and effective H5N1 and other potential pandemic influenza vaccines.

TERMS OF REFERENCE

She said the WHO would develop "terms of reference" on sharing viruses and any sharing outside those rules, including for vaccine development by drug companies, would require the consent of countries where the virus originated.

"We will take the recommendation to a WHO meeting in June to be formalised."

David Heymann, the WHO"e;s top bird flu official, did not say when the terms of reference on virus sharing would be completed but that "it will take much work still to develop" them.

He also said the U.N. body was working on a possible stockpile of vaccines in cooperation with pharmaceutical companies and donor countries.

"The sharing of viruses will be done in a manner that will not threaten public health security," Heymann said.

Thailand said last week it shared Indonesia"e;s concerns about access to bird flu vaccines, but had not decided to restrict access to its samples of the virus.

Some health and aid agencies had criticised Indonesia for refusing to share samples, while others defended the stance because developing countries often struggle to get access to life-saving drugs due to patent laws and high costs.

Sharing virus samples is crucial because it allows experts to study their make-up and map the evolution and geographical spread of any particular strain. Samples are also used to make vaccines.

Bird flu has swept through poultry across Asia to Africa and Europe. Experts believe it could mutate into a form that would easily pass from one person to another, possibly killing millions in months.

Total global capacity to make vaccines against a variety of diseases is only about 300 million to 400 million doses a year -- far below what would be needed in a pandemic.