Multiple Vaccines for Iraq-Bound U.K. Forces Not Harmful
Self-reported adverse events could be due to recall bias, research suggests
TUESDAY, July 1 (HealthDay News) -- British armed forces personnel did not suffer any adverse health effects from the multiple vaccinations they were given prior to deployment, according to research published online June 30 in BMJ.
Dominic Murphy, and colleagues at King's College London in the United Kingdom, conducted a study of 4,882 military personnel deployed to Iraq since 2003 and a subset of 378 people for whom vaccination records were obtained. The researchers looked for signs of psychological distress, fatigue, post-traumatic stress disorder and other physical symptoms.
Although personnel who reported having had two or more vaccinations in one day were more likely to also report symptoms of fatigue and multiple physical symptoms, once the number of actual vaccinations according to the individual's records were used as an independent variable, the associations became insignificant, the researchers report.
"One strength of this study was that we were able to analyze data from both self-reported measures and medical records about the number of vaccinations received. This allowed us to ascertain both the effects of vaccinations on health and the possible impact of recall bias," the authors write. "Recall bias was evident with self-reported measures of receipt of vaccinations. It is difficult to quantify the extent to which similar processes might have accounted for the reported associations between self-reported multiple vaccinations and illness after the 1991 Gulf war."