Re: A tale of two vaccines
A Tale Of Two Adverse Reaction Reporting Systems
On 26th March 2010 the MHRA published their final weekly running total of adverse reaction reports in respect of swine flu vaccines Pandemrix and Celvapan.(1) On June 2nd 2010, LAKEMEDELSVERKET, Medical Protection Agency in Sweden, (2) published their final report on adverse events for the Pandemrix vaccine, in the period between October 2009 and 16th April 2010.
The MHRA reported that………. “650,000 doses of H1N1 vaccines have been administered to healthy children aged less than 5 years in England to date (up to 14th March 2010). The safety profile of the vaccines in children is broadly consistent with that for seen for adults.”
It would become evident later that the incidence of narcolepsy would be far greater in children and young people than in adults.
The Swedish agency for virtually the same period stated that (in respect of Pandemrix only) ….. “700 000 doses have been used in children 6 months - 12 years of age. Preliminary data also indicates that about 421 000 children have received a second dose of the vaccine.”
The MHRA reported that they had “received a total of 440 reports of suspected adverse reactions to swine flu vaccines in children aged less than 16 years” and concluded that………….
“the majority of the reported suspected reactions in children are non-serious, recognised side effects of many vaccines including the swine flu vaccines, or can be attributed to the process of vaccination rather than the vaccine itself. These reactions include injection site reactions, flu-like illness, muscle aches and pains, rash, headache, dizziness, nausea, vomiting, diarrhoea and psychogenic reactions including faints”.
The Swedish MPA reported that………….
“In about one fifth of the reports concerning children (1-7 years of age) the reactions have been classified as serious, i.e. the same proportion as the reports for all ages” and that………………..
“The most frequently reported serious adverse events in children, reported from Health Care Professionals, were neurological reactions (82) ( e.g. febrile convulsions and syncope), immunological reactions (28) (e.g. anaphylactic reaction/allergic reactions) or general symptoms (26) (e.g. fever and influenza like illness).”
The MHRA not only stated that the “majority” of the ADR’s in children were “non-serious” but made no mention of an incidence of neurological reactions, something which was identified in Sweden as the most “frequently reported serious adverse event in children” following administration of the Pandemrix vaccine.
Sweden reported on 82 cases neurological reactions of febrile convulsions and syncope in the child cohort whereas the MHRA in their table of conditions reported on one case of “convulsion in childhood”. The MHRA tables make no mention of immunological reactions or anaphylactic reactions in children.
The most “commonly” reported ADR in Sweden was anaphylaxis.
“The most commonly reported immunological reactions have been anaphylactic/allergic reactions.”
The MHRA only reported one case overall (ie it is not known if it was in respect of a child) as “anaphylaxis treatment”.
Bearing in mind that the CHMP VARIATION ASSESSMENT REPORT for Pandemrix (3rd December 2009) included the fact that Pandemrix had only been licensed in May 2008 in respect of individuals between the ages of 18yrs and 60yrs, one has to wonder why it was that the MHRA (a) didn’t publish brand specific ADR tables in the final weekly report (b) didn’t collate and report on specific ADR’s in children and (c) didn’t identify the same serious ADR’s in children or the rate at which they were occurring to that identified in Sweden for the same period.
One explanation for the noticeable discrepancy between all aspects of the ADR reports in Sweden to that collated by the MHRA might lie in the fact that the MHRA system for ADR reporting in children was later identified in October 2014 to be potentially acting as a “barrier to reporting”.
“ADR reporting in children was "impractical for busy healthcare professionals and potentially acted as a barrier to reporting".(3)
Might this be a reason why, as the MHRA representatives pointed out, “there was no suggestion of a safety concern with Pandemrix at the time” ?.(4)
Rapid Response provided by…….
Dr Philip Bryan; Head of Vaccine Safety, Vigilance and Risk Management of Medicines (VRMM), Medicines and Healthcare products Regulatory Agency (MHRA)
Dr June Raine; Director, VRMM-MHRA
Dr Ian Hudson; Chief Executive, MHRA
Competing interests: No competing interests