In a technological leap forward, medical company Protein Sciences has produced and gotten approval by the FDA for a flu vaccine made of genetically engineered proteins gathered from caterpillars. Adults aged 18 – 49 years are cleared to receive the shot, with doses available in limited supply for the current flu season.
The vaccine, called Flublok, is produced by isolating a protein from the flu virus and inserting it into a virus that affects fall army worms. Then, billions of cells derived from army worms are infected with this recombinant virus. Once enough of the protein is produced, scientists extract and purify it for the season’s vaccine.
“Flublok is truly a modern vaccine. We use advanced scientific technology to make just the active ingredient of the vaccine without any other viral components. This is the first influenza vaccine on the market to do so,” said Manon Cox, CEO of Protein Sciences, in a statement.
The vaccine is considered a breakthrough because it significantly reduces the time needed to produce a flu vaccine and it is not produced using live viruses, which present a hazardous manufacturing risk.
Since strains of the flu virus change every year, scientists must produce a different vaccine each season. Current vaccines are made with millions of chicken eggs using a 60-year-old process. Hybridized strains of the virus are injected into the eggs, where they grow before being extracted. This process is time-consuming, imprecise, and poses a problem for those with egg allergies. Government officials have also expressed concern that if there were ever a widespread epidemic infecting birds, an egg shortage would prove a disaster for manufacturing the vaccine.
Flublok protects against three different flu strains just like currently available vaccines. However, it is 44 percent effective against all circulating strains of influenza, not just the ones the vaccine targets. It also trumps current vaccines in that it contains no preservatives and three times the amount of active ingredient to protect against the flu.
Detractors point out that the vaccine may not be any more effective than current vaccines at preventing illness, which protect people 62 percent of the time. What is needed, says Michael Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy, is a vaccine that protects 80 to 90 percent of the time. He was one of the lead researchers in a report released last November that said the flu vaccine was over-promoted, over-hyped and less effective than the CDC says it is.
But scientists are racing to produce an improved vaccine, especially a universal flu vaccine that would only have to be administered every 5 to 10 years. Already, two seasonal vaccines are approved that fight against four strains of flu rather than the usual three, and another manufacturing process akin to the caterpillar cell one uses dog kidney cells, also speeding up how fast vaccines can be ready for the public. More vaccines manufacturers are also now located in America rather than overseas in the case of a global pandemic. Flublok’s sister vaccine, Panblok, is designed to protect against pandemic influenza.
Written by Sarah Shultz for Diets in Review