I recently received a text message from a poultry farmer who said that he was confused about which vaccine should be administered to his poultry flock to protect the birds from the H5N1 Avian Influenza virus. “Homolog or heterolog? No real differences because outbreaks still happen in my poultry flock,” he wrote in his SMS.
I can understand his problem, but what could I recommend to him, except to maintain excellent biosecurity at his farm. Don’t ask about recombinant vaccine, because it’s still a controversy, and don’t ask about stamping out, because who will pay the farmer for it?! Yeah, too complicated.
I then went to meet with a professor from the faculty of veterinary medicine in Indonesia in order to get more insight as to what i could advise the farmer. “The AI virus still exists, even more virulent because of its rapid mutation. We have atleast 3 local strains of the AI virus, which are Legok, Konawe and Sukabumi. The vaccine, however, is made made from the Legok strain only. That’s not a surprise when you find outbreaks of AI virus,” said the professor.
The professor went on to say that the solution would be found in a cocktail vaccine, simply becasue a single strain vaccine is not able to protect the birds from the field virus. “In 2 years, the mutation of the AI virus is so siginificant. If we look at the philogeny tree of AI virus, one strain to another strain is far now in distance. So, how can a single strain vaccine protect the birds if field virus attacking is made of more than one strain and is more virulent? We need a cocktail vaccine that has atleast 2 or 3 local strains inside the vaccine to give maximum protection,” he said. He also informed that this solution is based on his challange trials. The vaccine tested are homolog (single), heterolog, and cocktail (polivalen) vaccine. The result, he says, is that the cocktail vaccine protects up to 90% of the total birds challenged.
So, i could possibly recommend a cocktail vaccine ot the farmer. Unfortunately, though, he still has to wait an unpredictable amount of time. The reason for this is that the government has not yet issued a permit to use a cocktail vaccine, although some animal vaccine companies are able to produce it. The reason for this is uncler, but the necessity for it is pressing.
Again, too complicated!