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HEALTH: Bird Flu – Vietnam Reports Headway in Human Vaccine

Tran Dinh Thanh Lam - Newsmekong*

HO CHI MINH CITY, Jun 3 2008 (IPS) - Vietnamese researchers have announced significant progress in their effort to develop a prototype vaccine for the H5N1 avian influenza, despite criticism from some scientists that their methods are "unorthodox".

Vietnam is hoping to develop a vaccine that could prevent humans from contracting bird flu and have it available on the local market at a reasonable price by late 2009.

Researchers from the National Institute of Hygiene and Epidemiology (NIHE) began a trial of the H5N1 influenza vaccine on 10 volunteers in March this year.

Encouraged by good results, researchers from the Vaccine and Bio-Technology Products Company (Vabiotech), affiliated to the NIHE, obtained permission in early April from the Ministry of Health to inject a shot of the experimental vaccine to 30 volunteer medical students from the Military Medical Academy.

"Good results from their blood samples allowed us to inject them a second shot on April 19," Dr Nguyen Thu Van, director of Vabiotech, said in an interview.

Dr Van said a larger-scale human testing process involving volunteers from the Military Medical Academy will be in two stages – the first will involve 30 volunteers, and the second 240.

During the first stage of testing, volunteers will be closely observed and their blood tested three times in order to evaluate the levels of antibodies created by the vaccine and any side effects.

Dr Doan Huy Hong, director of the Epidemiology Department at the Military Medical Academy, said his department would cooperate with Vabiotech. "The second stage will see how well the vaccine generates immunity in human bodies," Hong said.

"Once the vaccine’s stability has been proven, we could consider mass production," said Dr Van added optimistically.

She hopes to introduce the vaccine under the label of FLUVAX in late 2009. One injection of FLUVAX could bring up one-year immunity, and would be priced at 1.87 U.S. dollars.

Vietnam has recorded the second highest number of human cases of avian flu from 2003 to date, with 52 deaths out of 106 laboratory-confirmed cases after Indonesia’s 108 deaths from 133 reported cases, according to data from the World Health Organisation.

The vaccine that Vietnam is developing is specifically designed to combat the highly pathogenic strain of H5N1 known as VN1194. Vabiotech commenced its study in 2004 and started its tests on chicken and mice in January 2005.

Vietnam is one of only a few countries working successfully on the production of H5N1 vaccines, Dr Van said.

The research uses cell culture technology, which involves taking a deactivated or weakened form of the H5N1 virus from a patient who has died of bird flu. The sample is then cultivated in monkey kidney cells, a process the Vabiotech says can produce the best results within the shortest time.

"After effective results with mice and chicken in January 2005, we experimented on monkeys," said Dr Van. "We injected vaccine into some monkeys and found out they remained in good health three weeks after. This shows the vaccine is safe."

"Vaccine using monkey kidney cells will be more productive, cheaper and safer than a vaccine using the culture on embryonic chicken eggs currently being developed by other countries," he claimed.

Some international experts disagree, and have called the method used by Vietnamese scientists "highly unorthodox".

In an article in the Jun. 13 2005 edition of ‘Time’ magazine, a WHO expert warned that Vietnam’s vaccine could itself make people sick or even set off a pandemic.

The expert said that while the Vietnamese developers say they have followed international procedures to ensure that the virus has not mutated, they have not opened all their records or allowed an inspection of their labs.

"The danger is very unlikely," the magazine quoted Michael Perdue, a WHO virus expert who has consulted with Vietnam as saying. "But you just don't want to play with fire."

The deputy head of the NIHE, Pham Ngoc Dinh, said Vietnam was aware of WHO’s advice to countries not to jump into production of a vaccine specifically against the H5N1 strain because the virus could mutate, rendering any vaccine largely ineffective.

"Similar to other countries, we take this advice, but it does not mean that we will stop our research," he said.

"There could be some H5N1 mutations," countered Dr Van, "but NIHE scientists have already handy a technology that could provide a new vaccine whenever the virus mutates."

Sean Tobin, an official from WHO’s Hanoi office, told journalists in early May that while his office was not directly involved in Vietnam‘s development of a human vaccine for the H5N1 virus, it was satisfied that health authorities had rigorous guidelines for quality control.

"Certainly there would be some extra level of scrutiny required if they were to try and use this vaccine in other countries," he added. "But because the Vietnamese vaccine is intended only for domestic consumption, international authorities would not be involved in supervising the trials."

"But Vabiotech do have a lot of experience with other kinds of vaccines using monkey kidney cell technology, the government here (in Vietnam) feels quite confident in those vaccines," Tobin said.

"Vietnam has received support from international experts and the University of Japan, the leading country involved in research on vaccine production, to ensure the safety of the project," Van said.

Many Vietnamese experts support Van’s optimism, saying that any vaccine production process will lay down the necessary infrastructure so that the time used to make an eventual pandemic vaccine, anywhere between four to six months after a pandemic begins, can be shortened.

(*This story was written for the Imaging Our Mekong Programme coordinated by IPS Asia-Pacific)