Viral misconception

eAcH year, the World Health Organisation reviews evidence from previous years and determines the most likely flu viruses that should be covered by the vaccine programmes in the northern and southern hemispheres for the next influenza season.

Manufacturers of the vaccines adopt these recommendations and these products are then incorpo-

rated into nations’ vaccine programmes.

At this time, the vaccine is a good match for the predominant strain in Scotland, a variety of influenza A (H3N2). The proportion of the population who have received their vaccine is the same as last year.

There has been discussion between the Scottish Government and public health experts about the experience of s outhern hemisphere countries such as Australia for several months.

The predominant strain currently circulating in Scotland is not the same strain that was predominant i n Australia. Indeed there are differences even across the UK with which strain is predominant and this may fluctuate and change over the course of a flu season. Remaining vigilant about patterns of influenza activity continues to be important.

A small rise in all-cause mortality in the final weeks of 2017 has been reported as being a rise in ‘flu-related deaths’. It is not possible to infer this from the data available and it is too simplistic to say this was due to flu.

It is important to be clear about the terminology. When epidemiologists talk about ‘excess deaths’, this is a statistical term reflecting a greater number of deaths than would normally be expected.

Vaccination offers the best defence for people against flu and I would encourage those who are eligible but who have not received it to do so. GREGOR SMITH, Deputy Chief

Medical Officer for Scotland.