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a minha personal edition > vacinas > notícias
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DGDispatch
Flu Vaccine Possibly no Better than Placebo in Preventing Exacerbations in Asthmatic Children: Presented at ERS
By Cameron Johnston
Special to DG News
STOCKHOLM, SWEDEN -- September 16, 2002 -- Asthmatic children and other groups are usually encouraged to receive the flu vaccine each year as winter approaches. However, according to one study, the flu vaccine may be no better than placebo for preventing influenza-induced asthma exacerbations among children.
The study by practitioners at Erasmus University Medical Center, in Rotterdam, the Netherlands was presented in a poster session here on September 15th at the 12th Annual Meeting of the European Respiratory Society (ERS).
They began with a large cohort of 3220 asthmatic children aged six to18 years, whose names were drawn from family practices in the western Netherlands. They enrolled a total of 696 of the children. The study was randomised, double blind, and placebo-controlled.
One group of 347 subjects received a parenterally administered, inactivated influenza vaccine (flu shot), while 349 received a placebo throughout the winters of 1999-2000, and 2000-2001. Primary outcomes were number, duration and severity of asthma exacerbations associated with virologically proven influenza infection.
The children or their parents were asked to use a physician-derived checklist to keep track of exacerbations and to report any symptom score of four points or more. Those who had symptom scores of four or more points would be invited to the clinic to take part in further tests, mainly involving a throat swab.
Forty-four subjects in total underwent throat swabs. Those swabs that were positive for influenza were implicated in 42 asthma exacerbations. The exacerbations occurred in 24 of the patients who had received the vaccine and 17 who had received the placebo. Although more exacerbations were seen in subjects receiving the study drug, the difference was not statistically significant (p=0.44).
After adjusting for confounding factors such as length of the season, presence or absence of pets in the house, and presence of antibody titres for influenza, the researchers determined that the average exacerbation lasted 3.9 days longer in the placebo group, although there were no differences in the severity of the exacerbations recorded between the two groups.
According to Dr. Herman Bueving, of the Erasmus Department of Family Medicine, these findings suggest that while the flu shot does not reduce the number or severity of exacerbations in asthmatic patients, it can lead to exacerbations of a shorter duration.
Nonetheless, this data also suggests that extra care should be taken each year when winter approaches because not all asthmatics will have a favourable reaction to the flu shot, and some might even be better off avoiding this form of prophylaxis altogether.
Todo o conteúdo Copyright (c) 1995-2009 Doctor's Guide Publishing Limited. Todos os direitos reservados.
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