To assert that there are no long-term side effects, the Ministry of Health relies on the results of monitoring the side effects of seasonal influenza vaccines, produced by similar processes.
Seasonal influenza vaccines are generally well tolerated. If they cause side effects, they are mainly local reactions such as pain, redness, or swelling at the injection site. These effects may be followed by moderate fever for 48 hours.
What about Guillain-Barré syndrome?
The vaccines against influenza A (H1N1) having been carried out in an accelerated manner, some doctors had expressed doubts about the risks of adverse effects, evoking in particular the Guillain-Barré syndrome. This syndrome could occur especially during a flu vaccination. It is a disease affecting the nerves, which can be serious, although recovery is complete in 85% of cases.
The risk of developing Guillain-Barré syndrome due to the flu would however be much greater than the risk of such a syndrome occurring due to vaccination, according to the Ministry of Health.
National monitoring of the adverse effects of influenza A (H1N1) vaccination will be implemented. The French agency for the safety of health products (Afssaps), as well as the regional pharmacovigilance centers (CRPV) and the pharmaceutical laboratories concerned will closely monitor the occurrence of potential adverse effects.
