A study has found no link between illness among troops sent to Iraq and multiple vaccinations. Instead, it says the troops tend to blame poor health on multiple jabs even when they did not have them.

Several studies have linked ill health in forces in Iraq to multiple vaccinations, but Dominic Murphy, a psychologist at King's College London, said these relied on troops' own recollections, and should be re-evaluated.

"Multiple vaccinations given to personnel in the UK armed forces in preparation for deployment to Iraq are not associated with adverse health consequences when vaccinations are recorded objectively from medical records," said the study carried out by Murphy's team, published in Tuesday's British Medical Journal.

The team randomly selected nearly 5,000 men and women deployed to Iraq since 2003 and asked them about their health and how many vaccinations they recalled receiving.

The veterans more likely to report symptoms of fatigue, stress and other physical problems were those who recalled having two or more vaccinations in a single day, the study found. These people also rated their health as worse.

But when Murphy and colleagues checked the health records of 10 percent of these men and women selected at random, they found that, whereas 70 percent reported receiving one or more vaccinations on a single day, medical records showed only 43 percent got that many at once, Murphy said.

"This is the first time we have been able to access medical records instead of relying on just self-reporting," he said in a telephone interview.

"Ill solders are more likely to have recalled receiving more vaccinations when in many cases they actually did not have that many."

Many British and U.S. troops sent to Iraq have complained of poor health, similar to veterans of the 1991 Gulf War. Suspected possible causes include exposure to pesticides, uranium, nerve gas, other chemicals - and vaccinations.

A large U.S. review in 2006 showed that troops deployed during the 1990-1991 Gulf War get sicker than most other veterans but did not turn up evidence of a common "Gulf War Syndrome".

"Some of the studies that have implicated multiple vaccinations as a cause of illness for soldiers who served in Iraq should maybe be reinterpreted in light of our findings," Murphy said.

Troops sent to Iraq are routinely vaccinated against anthrax, tetanus, typhoid and yellow fever.