Amid SARS concerns, WHO urges influenza vaccinations for high-risk groups
2 September 2003 - The World Health Organization today called for vaccination of people at high risk of contracting influenza as a matter of urgency. Those in high risk groups include the elderly, people with weakened immune systems and those with underlying chronic diseases. WHO is also urging increased vaccination coverage in health care workers who have frequent contact with these vulnerable populations.
These WHO recommendations are especially aimed at reducing the number of cases in these high-risk groups, where influenza often leads to severe pneumonia and other serious illness due to pre-existing chronic diseases. In addition, reducing pneumonia cases may also lower the possibility of misdiagnosing influenza as SARS.
Because vaccine stocks are limited, there is a need for prioritization. For this reason, WHO recommends that priority for influenza vaccination be given to the elderly, those with chronic diseases, and others including health care workers who have frequent contact with these high risk groups.
Many respiratory diseases occur every winter but influenza is one of the most severe. Influenza typically infects 10% to 20% of the total population during seasonal epidemics, resulting in between three and five million cases of severe illness and at least 250 000 to 500 000 deaths each year worldwide. Influenza vaccine is safe and effective, and while some influenza vaccinated people may still contract mild influenza, the vaccine does protect from the most dangerous consequence of the disease, pneumonia.
While the human chain of SARS transmission has been interrupted, many experts are concerned that SARS might be a seasonal disease and return in the next few months, about a year after it first appeared in China.
The influenza vaccine does not prevent other respiratory diseases and, importantly, it does not provide protection from SARS. High vaccination coverage may reduce the number of pneumonia cases caused by influenza that might raise suspicions of SARS.
Suspected SARS cases can result in considerable disruption of health services as well as costly precautionary measures and investigations. Also, decreasing the number of pneumonia cases, through influenza vaccination, can help in the early identification of a true SARS outbreak – should the disease recur. Early detection is essential to keep the disease contained.
As important as it is, influenza vaccine remains chronically under-used. An estimated one billion persons worldwide are at high risk of severe illness, but only 250 million are vaccinated each year, mainly in industrialized countries. Vaccination coverage of health workers is also low in most countries.