Vaccine makers will not be ready to begin large-scale production of a vaccine for H1N1 influenza—the so-called swine flu—until mid-July at the earliest, according to a report released on May 18 by an advisory group to the World Health Organization (http://www.who.int/csr/resources/publications/swineflu/TC_report_2009_05_14.pdf).
The advisory group noted that candidate vaccine strains will probably become available at the end of May 2009, but that another 1 to 2 weeks might be needed for studies of attenuation characteristics in animal models. Manufacturers would then need to isolate rapid-growing strains to help ensure high yields, a process that typically takes 1 to 2 months.
Stephenson J. H1N1 Vaccine. JAMA. 2009;301(23):2432. doi:10.1001/jama.2009.817