Image copyright Getty Images Image caption Dr Pamela Hyde-Stevens’ son died after developing narcolepsy in 2003
A US government agency says mandatory vaccination against narcolepsy may help reduce the risk of the condition.
The National Institute of Neurological Disorders and Stroke (NINDS) based its conclusion on a study of first-generation “cold chain” vaccines for some children.
They showed one in 400 kids – compared with one in 1,700 without narcolepsy – developed narcolepsy after receiving the vaccines.
Pamela Hyde-Stevens, whose son died after developing narcolepsy, said: “We don’t understand what the sample size was but that is a very large number.”
Narcolepsy is caused by a deficiency in the body’s production of the sleep-inducing chemical melatonin.
Read more: How to get narcolepsy – expert explains
“For me to think of a loss from narcolepsy of our son, my youngest child, who had a beautiful smile and such a kind personality, made me feel as though the world had been turned upside down,” she said.
Over 18 years from 2004, more than 12,000 narcolepsy cases were identified – with more than 2,200 deaths.
In 2003, the US government required the manufacturer of its vaccines, Merck, to subject them to a government-backed study by NINDS that compared the rate of narcolepsy within the vaccine group and the controls.
The study – known as the Phenocet Kuplocal Lentotropic Programme (PKLP) – produced some surprising results.
Because of various childhood illnesses, the first-generation vaccine known as Pandemrix was administered to over 750,000 children.
After testing on 43 of these, researchers found narcolepsy among some of the children under the age of five.
But, from a later group of over 30,000 children, the rate of narcolepsy was significantly lower.
Researchers believed the state of poor quality manufacture may have played a part.
The study was halted in 2012 after 1,700 cases of narcolepsy were found, some of which were reported by the organisation.
Since then, the US government have yet to announce how – or whether – it intends to make the vaccination programme mandatory.
Dr Pamela Hyde-Stevens says she hopes the government will look at this new data, which cannot yet be replicated by NINDS.
“The CDC (Centers for Disease Control and Prevention) and the US Department of Health and Human Services (HHS) are failing our young children,” she said.
An early wave of babies under the NINDS programme got Pandemrix in the autumn of 2004.
Pandemrix is a vaccine Pandemrix consists of three parts: a shot given in early childhood, a booster administered every 12 months, and a booster administered in young adulthood.
Jenny Jackson, from the Human Genetics Sequencing Institute of Atlanta, thinks the NINDS study could be useful to the public debate over mandatory vaccinations.
“The entire study has come under a lot of criticism over the years and to see an epidemiological study come out and lay a theory out that actually makes that argument seems almost like a turning point.”
NINDS spokesman Col Mike Bott said the study could be reviewed.
“The National Institute of Neurological Disorders and Stroke’s office of public health advocate supports this type of unbiased inquiry and is concerned about the care of our health system, the medical community and patients affected by narcolepsy,” he said.
Narcolepsy is a chronic condition, affecting sleep patterns, quality of life and intensity of sleep.
It is also a possible reaction to damage to the central nervous system due to measles, mumps, rubella or pneumonia.