Flu vaccine grown inside insect cells shows promise

Influenza vaccines are usually produced in embryonated hen's eggs. However, there are disadvantages to this process as the eggs require specialized manufacturing facilities that are difficult to scale up rapidly. One potential alternative is use of the influenza virus hemagglutinin (HA; an antibody that causes red blood cells to clump together) using recombinant DNA techniques.

Researchers at the University of Rochester evaluated an experimental influenza vaccine consisting of recombinant HA expressed in yellow striped caterpillars by a recombinant baculovirus (rHA0).

The researchers found: “We have shown that the rHA0 vaccine is well tolerated in healthy adults and immunogenic at both doses evaluated, and we obtained preliminary evidence of protection against influenza infection and disease. The safety data generated in this study are consistent with the safety profile observed in previous studies of rHA0 vaccine.”

The researchers said that recombinant baculovirus is especially well suited for production of influenza vaccine because the rapidity with which genes can be cloned and inserted into this vector facilitates updating the vaccine at regular intervals. In addition, the high yields of protein possible in this system provide the opportunity to use much higher and potentially more effective doses of vaccine.

The authors concluded that larger studies are needed but the preliminary demonstration of efficacy provides further support for the development of this promising approach for prevention of influenza.