Jakarta Post : "RI bird flu virus, Let's keep in scientific loop", Dr. IGN Mahardika, Anggota Panel Ahli Komnas FBPI

I Gusti Ngurah Mahardika, Denpasar, Sat, 03/29/2008

The Indonesian bird flu virus might not become a pandemic vaccine seed and thus it is a far-flung idea to make it into a biological weapon.

In an influenza pandemic horror vision, world health politicians and experts agree on one point, a vaccine will be the most powerful medical intervention to reduce the morbidity and mortality caused by an influenza pandemic strain.

However, if "an Indonesian" thinks the Indonesian bird flu virus will be used as a pandemic vaccine seed, the geographical and serological data show it might not be the case.

Moreover, although Indonesian bird flu cases end mostly in the death of victims, the virus has no potential to be developed into a biological weapon.

It is true that the latest bird flu virus, a popular name for avian influenza virus of H5N1 subtype, cases in Indonesia are increasing a pandemic worry.

The sheer number of human cases and fatalities is steadily increasing. In 2005, 13 out of 20 (65 percent) cases were fatal. The rate has become 82, 88 and 83 percent in 2006, 2007 and until February 2008, respectively. The figure is the highest in the world. The overall fatality of world bird flu cases is only 63 percent.

Although the Indonesian virus seems to be "super" pathogenic, it does not automatically mean that the Indonesian virus is the most harmful in the world. It might simply be a matter of victims being late to seek medical help.

Moreover, pathogenecity is not the most important criteria in selecting a pandemic vaccine seed. The selection is especially based on the geographical distribution, epidemiology and genetic and antigenic character of a virus candidate.

The Global Influenza Program of World Health Organization (WHO) is continuously evaluating all influenza viruses -- not only H5N1 -- and selecting appropriate vaccine seed candidates as a part of pandemic preparation plan.

Based on the state of knowledge at this time, experts do not know whether the next pandemic will be caused by an H5N1 virus or other subtype. They mostly agree that the pandemic is a matter of when, not if.

The H5N1 virus is indeed a strong candidate. Therefore, international communities via the WHO need to analyze the dynamics of the bug. Selected vaccine candidates will be changed as needed.

In 2006, the WHO selected three viruses as candidates. They were A/Indonesia/5/2005-like, A/Bar headed goose/Qinghai/1A/2005-like, and A/Anhui/1/2005-like viruses. In 2006, the number became eight strains.

Given current geographical distribution and genetic characteristics, the Indonesian bird flu virus -- so-called Clade 2.1 -- will find its best use in Indonesia. The virus occurs in Indonesia. The best vaccine seed of choice for most of Asia, such as Thailand, Vietnam, Malaysia, China, Japan and Korea, will be the Anhui virus (Clade 2.3.4). While for the rest of Asia up to Africa and Europe it should be the Qinghai virus (Clade 2.2).

However, in case the pandemic epicenter is somewhere in Indonesia, the best seed will be the Indonesian virus. Current development strongly supports this scenario.

The steady increasing number of human cases in Indonesia shows that the bug is perpetuated or endemic archipelago-wide.

Carrier fowl continuously contaminate the environment. Available data throughout Indonesia allow us to conclude that sick and healthy fowl such as layer and broiler chickens, village chickens, ducks, geese and Muscovy ducks shed the pathogen via respiratory droplets and their droppings.

These animals can be clinically healthy due to vaccination or naturally resistant. Water fowl -- such as ducks and geese -- have long been known to be resistant to any influenza virus infection.

They can carry the virus without being sick. They act as a reservoir of the virus and continuously transmit it to other animals and humans. Village chickens seem to act the same role, to a somewhat lesser extent.

The ecology of the virus can be more complex than the current idea that the source of infection is mainly fowl. The role of human beings and other animals as silent disseminators can not be ignored.

In the case of silent infection, a human being and other animals such as dogs and cats can be infected and carry the bug in a tiny number before it will find a genetically susceptible human host. The level of infection is so low that it can not produce disease, nor an antibody response, in the carrying person or animal.

An environment of that kind is a paradise for the emergence of pandemic strain. The bug can reproduce and replicate continuously, which gives it the chance to mutate into what it will.

The answer to the question, can an Indonesian H5N1 virus be a pandemic vaccine, is "maybe yes or maybe no". It will definitely be yes if the pandemic is caused by H5N1 virus and starts here.

Although the virus is very fatal -- killing most sick people -- it absolutely can not be used as a biologic weapon.

It would be laughable if one put an effort into developing a biological weapon based on the bird flu virus.

The bug has the biggest potential to disseminate globally. There will not be any country in the world out of the line of its fire, including the country that some thought is developing this virus into a weapon.

At this pre-pandemic stage, it is global task to prepare for a potential pandemic caused by bird flu virus. Any development of the bug should be studied intensively to detect a pandemic at the earliest moment. This effort will save millions of human lives.

In strictly contained facilities -- known as bio-safety level 3 or higher laboratories -- every virus will be propagated before its molecular, antigenic and biological characteristics are unfolded. In case it shows its adaptability to mammals and humans, the influenza alert system will be rung. If the virus does not match antigenically with standard viruses, a new vaccine seed will be developed thereafter.

To my knowledge, there is no plausible reason not to send any Indonesian human viruses to a WHO network laboratory. Such state-of-the-art facilities are not available in Indonesia or not running yet.

If the benefit-sharing issues are the main reason to keep the virus, such a facility here should be accelerated. Based on global interest, we can not rely on global vaccine manufacturers in stockpiling pandemic vaccine to be used in Indonesia. This facility should be made available here.

Upgrading influenza vaccine manufacturers for fowls into human influenza vaccine producers is one short-cut alternative to be considered.

Human resources are available. We could propagate the resources if we need them. Trust to national resources should be given.

The writer is a virologist and staff member of the School of Veterinary Science at Udayana University in Denpasar, Bali. He can be reached at gnmahardika@indosat.net.id

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