Tuesday, January 18, 2011

Confused vaccine messages in the UK/ Telegraph

The UK's Telegraph is on a tear about flu vaccine.  Two weeks ago, the Telegraph complained that the UK government had dropped its flu vaccine advertising campaign.  Last year the UK spent 15 million pounds for swine flu vaccine ads.  But people are being vaccinated nonetheless:
After earlier complaints that the failure to advertise flu jabs had led to low take-up rates this winter, the UK chief medical officer, Professor Sally Davies, said that vaccination rates were now at normal levels for the time of year.
This week the Telegraph berated the government because jabs for children were stopped in north-west England, despite a 3 year old dying.  The Telegraph says this "has left parents feeling fearful and anxious."  Two experts, vaccine proponents, were quoted about feeling "uneasy" over the government's "stumbling" decision-making; the other was "very disappointed" about not vaccinating children as is routinely done in the US.  [It is not routinely done elsewhere in Europe.] 

An earlier Telegraph piece had more facts.  Government policy is to offer flu vaccine only to children at high risk due to an underlying condition.  This makes good sense, in terms of balancing risk and benefit.  Eighty per cent of the 70 children who died from flu complications last year had underlying health problems:  for such children, the potential benefit of vaccination is much greater than for otherwise healthy children.  Only 20% of UK child deaths from flu last year (14 children) were otherwise healthy.  Healthy children, being at much lower risk of death or serious injury would have a reduced benefit from vaccination relative to chronically ill children, but equal potential risk from vaccination.
According to the UK's Chief Medical Officer Sally Davies, "The data from the pandemic last year showed - and this year's data is very similar - that if you are in an at-risk group you are 18 times more likely to die of flu if you catch it than a healthy person, so we need to focus on getting those at risk to come forward and have vaccinations."
Should healthy children be vaccinated nonetheless?  The Cochrane Collaboration has found no evidence of benefit for flu vaccine in young children, based on metaanalysis of all published research, which Cochrane submits to a careful methodologic review.  If it is a very bad flu season with many child deaths, it might make sense to vaccinate regardless.  The Daily Mail reports 15 deaths in the 14 and under age group from flu in the UK this season.

But during Australia's 2010 autumn, flu vaccinations for under-5's were stopped due to seizures in one child per 110 vaccinated, and several child deaths after vaccination.  In other words, in very rare cases you may die from flu or from vaccine.  The vaccine works, at best, 70% of the time, and some seasons it is entirely ineffective.  It is also less effective in some groups compared to others.

We don't know what the side effect profile of a flu vaccine will be until after millions have been vaccinated, since the vaccine is newly designed each year with selected viral antigens,  Thus performing a reasonable risk-benefit calculation is difficult if not impossible.  Improving early data collection of benefits and harms would help this situation, and is greatly needed.

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