Flu

The US Food and Drug Administration has approved the world’s first influenza vaccine manufactured using an insect virus.

Flublok, manufactured by Protein Sciences, is produced using a ‘baculovirus expression system’ that does not require the virus to be grown in chicken eggs, as is usually the case.

This means the vaccine can be made quickly in the event of a pandemic and without any of the infectious risk traditionally associated with vaccine manufacture.

Karen Midthun, director of the FDA’s Center for Biologics Evaluation and Research, explained, "The new technology offers the potential for faster start-up of the vaccine manufacturing process in the event of a pandemic, because it is not dependent on an egg supply or on availability of the influenza virus."

"The new technology offers the potential for faster start-up of the vaccine manufacturing process in the event of a pandemic, because it is not dependent on an egg supply or on availability of the influenza virus."

Flublok has three times the amount of hemagglutinin (HA) – the active ingredient in all inactivated influenza vaccines – to help protect against two influenza virus A strains, H1N1 and H3N2, and one influenza virus B strain.

The vaccine is produced by insect cells which are infected by the baculovirus combined with the hemagglutinin gene. The cells are then grown in culture to churn out the protein.

Protein Sciences CEO Manon Cox said, "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."

The FDA approved Flublok for immunization in adults aged 18 to 49 after it was proved to be 44.6% effective against all circulating influenza virus during a study involving 2,300 people in the US.

The vaccine was indicated as safe to use during a separate study of 2,500 people.

Adverse events included pain at the site of injection, headache, fatigue and muscle aches, events also typical for conventional egg-based, inactivated influenza vaccines.


Image: Flublock will help protect against two influenza virus A strains, H1N1 and H3N2, and one influenza virus B strain. Photo courtesy of FreeDigitalPhotos.net.