Initial tests of a bird flu vaccine on monkeys in Vietnam have been successful, medical officials said on Friday, adding than tests in humans could be only months away.

Vietnam is the country hardest hit by an epidemic that has killed 47 people in Asia and caused the destruction of many millions of poultry.

Vietnamese researchers injected a vaccine based on weakened H5N1 bird flu virus in three monkeys early last month and three weeks later found the monkeys were healthy and had produced antibodies.

“Researchers have repeated the injections in the monkeys and we expect results in the next two weeks,” Nguyen Tran Hien, director of the National Institute of Hygiene and Epidemiology, told AMN Health.

Vietnam, where 14 people have died of the bird flu virus in the latest outbreak that began in December, hopes to have a vaccine ready for testing in humans later this year.

“Hopefully, in September tests will start for the vaccine on a small group of volunteers,” Hoang Thuy Nguyen, head of the vaccine research group, was quoted by the state-run Tuoi Tre newspaper as saying.

Nguyen told Reuters that after the results of the repeated injection are known, researchers will need to go through several steps to ensure the safety of the vaccine before testing it on humans, most likely on the members of his group.

The Thai government said it is considering an American request that a U.S.-developed vaccine be tested in Thailand, which is has also had new bird flu outbreaks although it has not reported any human infections since October.

“The study of pros and cons of testing a bird flu vaccine on humans will be submitted to the Public Health Minister for consideration on Monday,” said Paijit Warachit, director-general of the Public Health Ministry’s Medical Science Department.

RESILIENT

When asked if the next tests would include exposure of the vaccinated monkeys to bird-flu infected chickens, Nguyen said: “We are not able to conduct that type of test yet as Vietnam does not have a laboratory that is designed for such tests on animals.”

Experts said last month the effectiveness of a vaccine would be limited against a resilient virus that mutates into a form that can be spread between humans, which is their main fear. If it does mutate into this form, experts fear it could trigger a pandemic that might kill millions of people in a world population with no immunity.

The poultry virus has killed one man and infected three others - including a man and his younger sister - in northern Vietnam this month, although fewer outbreaks have been detected in poultry.

“All these infection cases have clinical factors related to slaughtering and eating poultry,” Health Minister Tran Thi Trung Chien said in a report published on the ministry’s Web site (http://www.moh.gov.vn).

“There is not yet any evidence of human-to-human transmission.”

The report did not mention a Cambodian woman who died in southern Vietnam in January. Some media reports have suggested she might have caught it from her younger brother, whose body was cremated before it could be tested for the virus.

Almost all the Asian victims - 34 Vietnamese, 12 Thais and the Cambodian - have caught it from infected poultry. Bird flu kills more than 70 percent of those who are infected, but doctors say victims can be saved if they are diagnosed early.