A study led by University of Michigan professor of chemical and biomedical engineering Henry Wang and doctoral student Lyle Lash found that training personnel to make cell culture vaccines in existing facilities is the only way to make enough doses to cover the US in a short time without requiring huge capital investments to build new dedicated flu vaccine cell culture facilities.
At present, most flu vaccines are made from hen eggs, but in light of a possible pandemic and ongoing shortages even during normal flu season, the government and private corporations like Novartis and MedImmune have been scrambling for new and faster ways to make a flu vaccine.
The researchers examined the economics of producing egg versus cell culture vaccines and identified time and capacity as critical factors in responding to a pandemic.
It obviously takes much longer to compile millions of hen eggs than it would to grow up existing cell lines from frozen vials, and while cell culture has a lower yield than egg culture, there is more existing capacity for cell culture than for inoculating and processing eggs.
"Based on existing dosages, we would have enough doses in about three to four months to cover the US with the system we propose," said Lash.
"Currently, it would take six months to make 250m to 300m doses of pandemic flu vaccine for the US, what we are proposing could make 600m doses in four months."
According to Lash, there are about 15 facilities in the country that make protein products from mammalian cell cultures where staff could be trained to make flu vaccines using cell cultures.
Indeed, many drug firms have been investing in developing cell culture flu vaccines due to government funding and the increase in price of the seasonal flu vaccine.
Before fears of an avian influenza pandemic and a vaccine shortage took hold, one dose cost about $1.6 (€1.2), whereas now each dose commands $8 to $10.
Lash pointed out that this profit margin is still low compared to the profits that existing cell culture facilities can make off their protein products.
However, there is a cost associated with switching to cell culture, stemming from the downtime necessary to train personnel and to run test batches.
Yet with research into different processes for purifying the vaccine, it would not be necessary to renovate facilities.
Nevertheless, Lash said there must be some type of government funding to subsidise companies for lost production time due to training staff.
Researchers envision a sort of national guard approach, with staff trained and on standby to respond to an pandemic.
The study received a warm reception at the American Chemical Society National Meeting earlier this month.