Side effects from Pandemrix® from 11 to 16 November 2009

Summary

In the period 11 - 16 November, the Danish Medicines Agency received 73 new side effect reports related to the Pandemrix® vaccine against influenza. The 73 persons vaccinated with Pandemrix® had experienced a total of 280 side effects.

The number of side effect reports submitted since 4 November totals 86, covering altogether 314 side effects. 91% were submitted by doctors, 9% were reported directly by Danish citizens who had been vaccinated.

The tables below show the total number of side effects distributed on four categories: reactions at the injection site (29), allergic reactions (30), other known adverse reactions (201), unknown adverse reactions (54).

Most of the adverse reaction reports are not serious and describe already known adverse reactions.

Most of the reports concern adults aged between 19 and 64. Two thirds of the reports concern women.

Eight reports are serious, and comments are given below.

The Danish State Serum Institute has so far dispensed a total of 440,000 vaccine doses. The exact number of persons vaccinated is unknown, but is estimated to involve at least 110,000 individuals.

The Danish Medicines Agency concludes that the adverse reactions seen so far after vaccination with Pandemrix® correspond to expectations.

Both doctors and patients are encouraged to continue reporting adverse reactions to the Danish Medicines Agency.

The next update about adverse reactions will be published in the middle of next week.

From 11 - 16 November, the Danish Medicines Agency received 73 new reports covering a total of 280 suspected adverse reactions. The total number of adverse reaction reports / adverse reactions has climbed to 86 / 314, respectively.

Consumption
The Danish State Serum Institute has dispensed a total of 440,000 vaccine doses. The exact number of persons vaccinated is unknown, but is estimated to involve at least 110,000 individuals.

Who have reported the side effects?
91% of the adverse reaction reports were submitted by doctors and other healthcare professionals, while 9% were submitted by persons that had been vaccinated.

Age distribution
The age distribution (based on reports where age had been disclosed) is as follows:

Gender distribution

Categorisation of side effects (adverse reactions)
The adverse reactions fall into four categories:

1. reactions at the injection site
2. allergic reactions
3. other known adverse reactions
4. unknown adverse reactions.

Notes on specific reports
Eight of the reports are classified as serious, they describe:

• one case of poor general condition, involving blood pressure fall, shortness of breath and vomiting as well as pain at the injection site, in the upper arm and the right side of the chest,
• one case of stomach pain and diarrhoea,
• one case of stomach cramps and fainting,
• one case of suspected carpal tunnel syndrome (compression of one of the nerves in the hand) with symptoms of swelling, abnormal sensation and pain,
• one case of seizure,
• one case of spontaneous abortion,
• one case of cardiac arrest where the patient was resuscitated,
• one case of death.

In the first two cases, the Danish Medicines Agency evaluates that there may be a connection to the vaccination, and most of the symptoms are known.

The third case involved a person who had previously responded by fainting when subjected to pain. The Danish Medicines Agency evaluates that there may be a link to the vaccination.

In regard to the fourth and fifth cases (carpal tunnel syndrome and seizure), the submission of additional details is necessary before a full evaluation can be made.

In the latter three cases, the Danish Medicines Agency assesses there to be NO link to the vaccination.

Spontaneous abortion is relatively common early in pregnancy.

The cardiac arrest involved an elderly patient with known chronic heart disease with a recent blood clot in the heart and pneumonia. The patient was resuscitated and suffered no complications.

The fatal outcome involved an elderly patient with known chronic heart and lung disease, and death is not suspected to be linked to the vaccination.

Overall evaluation
The first adverse reaction reports after vaccination with Pandemrix® in Denmark primarily describe known and expected adverse reactions that appear from the summary of product characteristics. See the factbox to the right.

General information about adverse reaction data
An adverse reaction report contained in the pharmacovigilance database does not necessarily imply that the adverse reaction is associated with the medicine (causality).

• The Danish Medicines Agency registers information about an adverse reaction in the database even if it is only suspected that there might be an association between the medicine and the adverse reaction. Therefore, the information in the database may include real adverse reactions from a medicine as well as random incidences due to e.g. a disease in the patient or another medicine which the patient is receiving at the same time.
• The Danish Medicines Agency is only notified of a small proportion of all adverse reactions. Therefore, the information in the pharmacovigilance database cannot indicate the frequency of the adverse reactions.
• A single adverse reaction report may contain more than one adverse reaction. Therefore, the number of registered adverse reactions is usually higher than the number of adverse reaction reports.
• An adverse reaction is considered to be serious if it results in the patient's death, is life-threatening, requires hospitalisation, results in significant disability, or if the patient is unable to work or go to school.
• The Danish Medicines Agency sends information about all serious adverse reactions to the marketing authorisation holder, to the European pharmacovigilance database and to the WHO.
• All reports must form part of the periodic safety update reports which the marketing authorisation holder must regularly send to the Danish Medicines Agency. A periodic safety update report describes all reported adverse reactions from all countries in which the medicine is marketed. The periodic safety update reports thus provide a good overview, and they form an important basis for continuous updates of the summary of product characteristics and the package leaflet.
• An unknown adverse reaction is an adverse reaction that is not listed in the summary of product characteristics. If it appears that it is a new, as yet unacknowledged adverse reaction, the adverse reaction will be added to the summary of product characteristics.

For further information, please contact Chief Medical Officer Doris I. Stenver, Consumer Safety Division, tel.: +45 4488 9247 or mobile +45 2246 0979.

Danish Medicines Agency, 19 November 2009 (updated 4 january 2010)