Daiichi misses H5N1 vaccine production goal after low yields slash output

Production of vaccines to protect against pandemic flu strains H1N1 and H5N1 has consistently been dogged by low yields. In many cases the seed strain is to blame, but Daiichi Sankyo has now encountered difficulties when processing the vaccine. The upshot is the drugmaker is unable to hit the H5N1 vaccine production target it agreed upon with the Japanese government.

In August 2011, Daiichi committed to creating the capacity to supply the Japanese Ministry of Health with 40 million doses of H5N1 vaccine within 6 months of being told to start production. The deadline for establishing the production capabilities is the end of this month, but Daiichi has already told the ministry it will fail to meet this target. Daiichi first realized it had a problem in October but has been unable to increase its forecast output beyond 20 million doses within 6 months.

The production shortfall stems from two processing steps--zonal ultracentrifugation and final filtering--which are causing yields to fall well below predicted levels. Daiichi discovered the operations were diminishing yields during process validation of its cell-culture production plants. In the resulting investigation Daiichi established that antigen yield is being held back by suboptimal process conditions during ultracentrifugation and the clogging of vaccine on the filter.

Daiichi gave a vague outline of its plans to increase yields in its press release, but it hasn't publicly predicted when it expects to hit its 40-million-dose target. The success of Daiichi's attempts to increase output at its cell-culture plants has important implications for Japan's pandemic preparedness and potentially for global readiness.

Vaccine manufacturers have tipped cell-culture production plants--like Novartis' ($NVS) government-backed facility in North Carolina--to overcome the problems of egg-based production. Failure to fulfill this potential could leave governments struggling to quickly source enough vaccines to cope with a pandemic.

- here's the press release