Making a Flu Vaccine Without the Virus

A new vaccine strategy could make flu shots cheaper, safer, and easier to produce. Using synthetic messenger RNA (mRNA) instead of proteins purified from viruses, German scientists have shown they can protect mice, ferrets, and pigs against influenza. "This is a very interesting new approach," says Hans-Dieter Klenk, a virologist at the University of Marburg in Germany who was not involved in the work. 

Now, most flu vaccines consist of hemagglutinin and neuraminidase, the two proteins covering the surface of the virus. To produce these molecules, the three predominant influenza strains are cultured in fertilized chicken eggs or, increasingly, in cell culture. Virus is then harvested and broken up so that the two proteins can be purified