The evenings are drawing in and, despite the mild autumn weather, it's that time of the year again. Getting a flu vaccination can reduce your chances of falling victim to the annual winter threat to our health.
In fact, last winter was a benign one as far as influenza was concerned. According to figures from the National Disease Surveillance Centre, which records the incidence of flu through a national network of practices, there was a dramatic fall-off in the number of cases reported for the 2001/2002 flu season.
But we should not be lulled into a false sense of security by these figures. The influenza virus has an enormous capacity for changing its structure and can become markedly virulent without warning. Scientists agree that we came very close to a severe pandemic in 1997 when a number of people in Hong Kong were killed by a hitherto unseen strain of flu. If it had not been for the quick reaction of public health authorities and epidemiologists in tracing the flu and arranging the slaughter of one and a half million chickens - the source of the virus - in the former British colony, the world would have felt the effects of a major outbreak to rival the infamous "Spanish Flu" of 1918. It killed up to 40 million people world wide.
The ideal time to be vaccinated against influenza is from mid-September to the end of October. It can take up to two weeks after the flu shot for antibody levels to rise to a level which offers protection against the virus. And, unlike other vaccinations, the flu vaccine must be given every year.
There is a a growing trend for employers to offer the vaccine to employees. Healthcare workers in particular are at increased risk of transmitting influenza to patients in high-risk categories, but scientific evidence shows that all workers can benefit from vaccination.
A study by Dr Karen Margolis and her colleagues in Minneapolis published in the New England Journal of Medicine in 1995 demonstrated substantial health-related and economic benefits following the vaccination of healthy working adults. The researchers recruited 850 workers aged 18-64 and randomly assigned then to receive either influenza vaccine or placebo injections in the autumn of 1994. Those who received the flu vaccine reported 25 per cent fewer episodes of respiratory illness and 43 per cent fewer days sick leave during the following influenza season. A British study from 1996 echoed these findings and concluded that annual vaccination campaigns in the workplace are cost-effective.
Dr Blánaid Hayes, consultant in occupational medicine at Beaumont Hospital, is very much in favour of occupational influenza vaccination, especially for healthcare workers. "Now that we have the Department of Health's imprimateur for this, we need to move forward and focus on the immunisation of clinical healthcare workers," she says. She points to a study of staff immunisation in a number of British nursing homes, which noted a significantly reduced death rate among the older residents of the homes where staff received the flu vaccination.
One of the principal reasons given by people for refusing the flu vaccine is a fear of side-effects. In fact, the vaccine has a good safety record, especially when given by a doctor or practice with detailed knowledge of your personal medical history. Proposals to administer the vaccine in supermarkets in Britain could be open to criticism on this account. Severe side-effects, such as an overwhelming allergic reaction (anaphylaxis), are very uncommon.
IN A study of side-effects in health personnel, most reported a mild local soreness at the injection site. An area of hardness and redness is less common and disappears in days. A fever, muscle aches and a feeling of tiredness occuring six to 12 hours after immunisation may affect one in five people, but these are irritants rather than major side-effects. The vaccine does not contain a live virus and so cannot cause an attack of influenza. The only absolute contraindications to influenza vaccine are a proven severe allergy to eggs and an acute illness causing a temperature at the time of vaccination.
If your employer is offering free flu vaccines this month, give it some serious consideration . You could enjoy a healthier winter as a result.
Annual influenza vaccination is strongly recommended for:
- Older people over 65 years of age
- Adults and children over six months of age with any of the following conditions: chronic respiratory diesease, chronic heart disease, diabetes
- Persons whose immune system is suppressed due to disease or treatment, including those with a missing or non-functioning spleen
- Residents of nursing homes and other long-stay residential facilities
- Children receiving long-term aspirin therapy who may be at risk of developing Reye's syndrome following influenza infection
- Healthcare workers and carers of those in the at-risk groups
Dr Muiris Houston can be contacted at mhouston@irish-times.ie. He regrets he cannot answer individual medical queries