Vaccines for pandemic influenza
This page provides information on the authorisation and use of vaccines against pandemic influenza.
Influenza vaccines are used to immunise people against a flu virus that is in circulation among the population. They are one of the most effective means for preventing people from becoming infected and for controlling the spread of the disease.
Normal flu vaccines, which are designed to protect against seasonal flu, are not intended to be used during a flu pandemic. Instead, pandemic-influenza vaccines need to be specifically developed.
Because the strain of flu virus that will be involved in a pandemic is not known before a pandemic is imminent, pandemic-influenza vaccines can only be prepared once a pandemic has started and the strain of flu virus responsible is identified.
In the European Union (EU), the European Commission and the European Medicines Agency have put procedures in place to speed up the assessment and authorisation of vaccines for use during a flu pandemic. There are two main procedures for the authorisation of pandemic-influenza: the mock-up and the emergency procedures.
The mock-up procedure
The mock-up procedure allows a vaccine to be developed and authorised in advance of a pandemic. Mock-up vaccines contain a strain of flu virus that few people have been exposed to but that could potentially cause a pandemic. The vaccines are tested to determine whether they will protect people against the virus strain that they contain.
Once the actual virus strain causing a pandemic is identified, the manufacturer can include this strain in the mock-up vaccine and apply for the vaccine to be authorised as a 'final' pandemic vaccine.
Four 'mock-up' vaccines are currently authorised in the EU. These can be modified into pandemic-influenza vaccines in a future pandemic:
- Pandemic Influenza Vaccine (H5N1) (Split Virion, Inactivated, Adjuvanted) GlaxoSmithKline Biologicals
- Pandemic Influenza Vaccine H5N1 Baxter
The emergency procedure
The emergency procedure allows for fast-track approval of a new vaccine developed after a pandemic has been declared. Authorisation of these pandemic vaccines is quicker than for a normal vaccine, as the information submitted by the manufacturer is assessed in an accelerated timeframe, taking around 70 'active' days instead of the usual 210.
Modification of seasonal flu vaccines
A third procedure allows vaccines authorised for use against non-pandemic, 'seasonal' flu to be modified so that they can protect people against pandemic flu.
Prepandemic vaccines are intended for use before a pandemic to protect against a strain of flu that could cause a future pandemic. The prepandemic vaccines currently available contain the virus strain A/H5N1 ('bird flu') because health experts believe that this strain could cause a future flu pandemic.
Four prepandemic vaccines are authorised centrally in the EU: