The U.S. Food and Drug Administration announced it has approved the use of a new flu vaccine, manufactured by using an insect virus expression system and recombinant DNA technology. The vaccine is a trivalent, meaning that it is a combination of three flu strains. For the 2012 – 2013 influenza season it is formulated to contain each of the following 3 influenza virus strains: A/California/7/2009 (H1N1), A/Victoria/361/2011 (H3N2), and B/Wisconsin/1/2010.
The vaccine is called simply Flublock. The FDA claims to have tested the product on approximately 2500 people, with a few “minor” side effects, and warns about a possible major side effect, including Guillian Barre syndrome, (GBS). GBS is usually characterized by rapidly developing motor weakness and the absence of reflexes. The vaccine product information sheet can be obtained from the FDA website accessible here.
Under warnings and precautions it cites the following:
“The 1976 swine influenza vaccine was associated with an increased frequency of GBS. Evidence for a causal relation of GBS with other influenza vaccines is inconclusive; if an excess risk exists, it is probably slightly more than one additional case per 1 million persons vaccinated. If Guillain-Barré Syndrome (GBS) has occurred within 6 weeks of receipt of a prior influenza vaccine, the decision to give Flublok should be based on careful consideration of the potential benefits and risks.”
Numerous scientific studies have, however; indeed demonstrated a causal link between influenza vaccines and GBS, including finding a direct causal relationship between different vaccine manufacturers and the onset of GBS after vaccinations. A more recent Canadian study demonstrated a small but significant risk of GBS in the HN1 vaccine influenza population. HN1 is one of the vaccine strains contained in Flublock. A 2012 study by Wise et al. published in the journal of epidemiology demonstrates a 57% higher immediate causal link of contracting GBS if vaccinated with PH1N1, (a monovalent single strain vaccine), compared to a non vaccinated population.