Cold adaptation generates mutations associated with the growth of influenza B vaccine viruses

Abstract

Seasonal inactivated influenza vaccines are usually trivalent or quadrivalent and are prepared from accredited seed viruses. Yields of influenza A seed viruses can be enhanced by gene reassortment with high-yielding donor strains, but similar approaches for influenza B seed viruses have been largely unsuccessful. For vaccine manufacture influenza B seed viruses are usually adapted for high. -growth by serial passage. Influenza B antigen yields so obtained are often unpredictable and selection of influenza B seed viruses by this method can be a rate-limiting step in seasonal influenza vaccine manufacture. We recently have shown that selection of stable cold-adapted mutants from seasonal epide..