GlaxoSmithKline influenza H1N1 vaccine approved

influenza-vaccineGlaxoSmithKline’s inactivated 2009 influenza H1N1 vaccine has been approved by the US Food & Drug Administration and by Health Canada. This action completes the list of pandemic H1N1 vaccines which I previously summarized for the US and Canada.

Influenza A (H1N1) 2009 monovalent vaccine is produced by ID Biomedical Corporation of Quebec, a wholly-owned subsidiary of GlaxoSmithKline. The US package insert can be found here (pdf) and the Canadian package insert here. Dosing recommendations for Canada are listed here. Health Canada has also posted a FAQ on the H1N1 vaccine.

The ID Biomedical vaccine is available only in multi-dose vials which contain thimerosal. Each 0.5 ml dose contains 15 micrograms of viral antigen. Other components of the vaccine listed at Health Canada include ‘trace amounts of egg proteins, formaldehyde, sodium deoxycholate and sucrose’. The presence of these compounds reflects how the vaccine is produced: the viral strain is propagated in chicken eggs, purified by centrifugation on sucrose gradients, inactivated with formaldehyde, and disrupted with sodium deoxycholate.

The vaccine has been tested in healthy adults but not in the elderly, adolescents, or children. Approval by both the US and Canada was based on the data from testing of the H1N1 and seasonal influenza vaccines, which are made by an identical process.

In healthy adults, the 2009 H1N1 vaccine produced the typical range of side effects, including pain at the injection site, redness, fatigue, and headache. Twenty-one days after injection of a 15 microgram dose, 93.9% of 66 adults produced an immune response, defined as a hemagglutination-inhibition titer of 1:40 or greater (which correlates with protection against infection). Only slightly higher seroconversion rates (97% of 66 adults) were observed when 21 micrograms of antigen were injected. Clinical trials are ongoing in North America, Europe, and Japan.

The GlaxoSmithKline vaccine is now available in Canada, but is not expected to ship to the US until December.