Controversy over effectiveness of flu vaccine

Gary Finnegan

Gary Finnegan

November 10th, 2011

Gary Finnegan

‘With seasonal influenza vaccination campaigns in full swing across Europe, a new review paper published in a leading medical journal has said the efficacy of the flu vaccine is around 59% and vaccine effectiveness is variable.’

Effectiveness-of-flu-vaccineIn reviewing the available evidence, the US-based authors found that six (35%) of 17 analyses showed significant protection against “medically attended influenza” but some scientists have expressed concern that the public debate that followed the article’s publication could affect immunisation rates.

The widely-reported article published in The Lancet says evidence for protection by flu vaccines in people older than 65 is lacking and the authors call for greater efforts to develop new vaccines against influenza.

Researchers are currently working on developing the next generation of influenza vaccines which they hope will be more effective in all subgroups of the population. 

Health authorities across Europe have been encouraging people in high risk groups, including older people, to have the seasonal flu vaccine as winter sets in.

Read: Flu vaccines can help keep older people out of hospital

The European Centre for Disease Prevention and Control (ECDC) responded to the report, by highlighting its Influenza Monitoring Vaccine Effectiveness in Europe (I-MOVE) initiative.

The I-MOVE project monitors seasonal and pandemic flu vaccine effectiveness (measured through influenza-like illness, then confirmed as influenza case) in ten EU countries and it expects to publish results for 2010 – 2011 shortly.

The ECDC said its figures show the efficacy of flu vaccines has ranged from 59% in people over 65 in 2008-2009 to 72% when all age-groups are included during the 2009-2010 pandemic season.

“ECDC notes that although influenza vaccines do not provide a complete protection against influenza virus but they are the most effective preventive measure. Development of more effective vaccines is certainly to be considered by ECDC to be a priority for researchers and vaccine manufacturers,” the agency said.

ESWI scientists slam research

Press reports casting doubts on the value of influenza vaccination were criticised by the European Scientific Working group on Influenza (ESWI) which issued a strongly-worded statement saying that “doubting the benefits of influenza vaccines is ethically and scientifically unacceptable”.

Prof Ab Osterhaus of Erasmus MC in Rotterdam, and Prof Peter Openshaw of Imperial College London, said using a certain type of effectiveness data, measuring protection against influenza-like illness without influenza confirmation, is the wrong approach to assessing whether vaccination is worthwhile.

“Relying on effectiveness studies to demonstrate the benefits of influenza vaccines is utter scientific nonsense. Worse yet, misconstruing scientific data holds severe dangers to public health protection,” said Osterhaus and Openshaw.

Read: Flu expert – ‘Misconceptions affecting vaccine uptake’