A new, faster-to-make whole-virus bird flu vaccine may protect against multiple bird flu strains, early studies in humans suggest. The new H5N1 vaccine appears to be safe, more effective than the one currently approved for human use and also able to be manufactured much more quickly than conventional vaccines, researcher said.

Current flu vaccines are grown in fertilized hens' eggs and the long process takes 22 weeks. Due to this drawback, the vaccine can only be manufacture seasonally, when the eggs are available.

However, the new vaccine is grown in green monkey cell lines and takes only 12 weeks to produce. The quick time could be a huge advantage, given how quickly flu pandemics spread, WebMD reports.

The new vaccine consists of two shots that are given three weeks apart. The most effective dose of the vaccine provided 76 percent immunity to the bird flu virus, much better than other vaccines. The researchers used whole virus that has been killed by chemicals and ultraviolet light, rather than virus fragments as is the case with competing vaccines, thus making the new vaccine more effective.

Whole-virus vaccines usually are more capable of producing an immune response also tend to cause more reactions in people receiving the vaccine than vaccines using viral subunits.

The new vaccine is manufactured by Baxter healthcare, leader in pharmaceutical inductry for more than 75 years. The vaccine, called Celvapan, is made in Bohumil in the Czech Republic under strict safety conditions, in biosafety level 3 laboratories.