Fast method for preparing flu vaccine developed

Someday, effective vaccines might be produced two to four times the speed of vaccines manufactured in fertilized chicken eggs, according to a researcher in the Netherlands.

Manon Cox of Wageningen University has developed an alternative process for producing large quantities of safe and effective vaccines using a process based on using cells in bioreactors.

Cox was conferred with a doctorate Dec. 9 at Wageningen University based on the strength of a thesis on this subject.

At the moment, it takes three to six months to produce a vaccine to counter a new strain of flu virus using chicken eggs. Moreover, there is no possibility of expanding production capacity in the event of a pandemic, as the limited availability of fertilized chicken eggs needed for production inevitably becomes an insurmountable problem.

Cox's new process indicates that it is possible to make a vaccine available in commercial quantities within 45 days, according to the university.

The new production method uses a baculovirus that multiplies only inside insect cells, and which cannot spread in vertebrates. The insect cells produce huge quantities of so-called HA proteins, which mobilize the immune system into fighting the flu virus.

The aspect that most slows down the production of vaccine according to the conventional method is the need for fertilized chicken eggs.

Furthermore, this creates extra problems if the flu virus is also capable of infecting birds (as was the case in the Netherlands in 2003), as the egg production often grinds to a halt. In addition, the vaccines produced are not suitable for people with an egg allergy. The new production process using insect cells can be used on a large scale, at all times and simultaneously at various locations throughout the world.

The process can easily be adapted to new influenza strains and enhance pandemic preparedness.

Meanwhile, the new production process has already been put through clinical trials involving three different strains of flu virus in 460 healthy people.

None of the test subjects injected with the vaccine developed symptoms of flu, while 4.6 percent of those taking part in the control group contracted the disease naturally.

Three follow-up studies involving approximately 3,000 people showed no striking or frequent side effects. The vaccine also appears to protect people from influenza viruses that have undergone genetic changes and in more than 50 percent of cases; it results in better antibody production than the flu vaccines currently available.