THE bird flu epidemic in Asia has reached such proportions that it may only be a matter of time before a strain capable of spreading from person to person emerges, World Health Organization officials are beginning to fear. If that happens, experts who have been warning that US efforts to protect against bioterrorism are undermining our defences against the much greater threat posed by natural outbreaks might be able to say 鈥渨e told you so鈥�.
This is because a vaccine against the new flu strain would have to be mass-produced, and fast. The first step, creating genetically engineered 鈥渟eed鈥� viruses that carry the surface proteins of the H5N1 bird flu, should be finished in less than a month. It should then be possible to make 750 million doses of a one-strain flu vaccine in just months, by growing the seed strain in chicken eggs. The problem could be finding enough eggs, especially after February, when companies will begin making ordinary flu vaccine for the next northern winter. If a pandemic does emerge, they will have to dump those eggs and find more for producing the H5N1 vaccine.
Fortunately, there is a factory in the Czech Republic capable of making 50 million vaccine doses using human cultured cells, without needing any eggs at all. Even better, its owner, the US-based multinational Baxter, built it to make flu vaccine. When it opened in 2002, however, it was co-opted to make smallpox vaccine for the US biodefence stockpile.
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