Update on the National Monitoring Experience with Pandemic H1N1 Vaccines

Notice type: Advisory

Date: 18/02/2010


Product name or type:
Pandemic H1N1 Vaccines

Problem Or Issue:
The H1N1 vaccines in use in Ireland are Pandemrix and Celvapan and it is estimated that approximately 1.6 million doses have been distributed. It is estimated that over 850,000 doses have been administered in Ireland to date, with Pandemrix now being used in the majority of patients. 

Since the start of the vaccination campaign adverse reaction reports have been submitted to the IMB on a voluntary basis by healthcare professionals and members of the public, either through the online reporting tool available on the IMB website (www.hpra.ie), or by post or telephone. Reports of suspected adverse reactions occurring in Ireland have also been notified to the IMB by the Marketing Authorisation holders for Pandemrix (GSK) and for Celvapan (Baxter). 

The reporter does not have to be sure that the vaccine caused the reaction, a mere suspicion will suffice. Therefore the reports received may be true adverse reactions to the vaccine, they may be events related to the process of vaccination rather than to the specific vaccine itself, or they may be coincidental events which have occurred post-vaccination but which would have occurred anyway even if vaccination had not taken place (e.g. they may be due to an underlying medical condition). 

Suspected adverse reaction reporting rates are highly variable and are dependent on many factors. Therefore these data cannot be used to determine the frequency of occurrence of adverse reactions to the H1N1 vaccines. 

In the past two weeks (Tuesday 2 February to Tuesday 16 February 2010), 144 reports of suspected adverse reactions to the Pandemic H1N1 vaccines (Pandemrix and Celvapan) have been received by the Irish Medicines Board (IMB). A single report may include more than one suspected reaction. The reports received to date remain consistent with the expected pattern of adverse effects for the pandemic vaccines. 

At least 36.3 million people have been vaccinated with the centrally authorised H1N1 vaccines in the European Economic Area and the balance of risks and benefits for the vaccines remains positive. 

A detailed report on the adverse reactions received by the IMB to date can be found at the link below. 

IMB National Monitoring Update (18/02/2010)

Background Information Or Related Documents:
Update on the National Monitoring Experience with Pandemic H1N1 Vaccines Document

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