Finland's national health institute said on Thursday its latest research on previously found links between children's narcolepsy and GlaxoSmithKline's Pandemrix vaccine against swine flu also involved a genetic risk factor.
In Finland, 98 narcolepsy cases have been reported following Pandemrix vaccinations.
The institute said research showed children aged 4-19 who were vaccinated against the H1N1 pandemic flu had a 12.7 times higher risk of experiencing narcolepsy than those who were not.
It has also now found that there was also a genetic factor associated with the risk.
Separately the ministry of social affairs and health said the Finnish pharmaceutical insurance pool would in the next few weeks decide on compensation for those who suffered from narcolepsy following swine flu shots.
A GlaxoSmithKline spokesman said the company had a commitment to ongoing research into narcolepsy — a condition that was poorly understood and characterized.
"GSK is committed to patient safety and continues to work closely with the European Medicines Agency (EMA) and other national regulatory organizations in the best interest of patients," he said.
Further information from ongoing studies is still needed in order to gain additional insight into the cause of the reported cases of narcolepsy.
"In addition, GSK has committed to conduct further research into any potential association between Pandemrix and narcolepsy and will seek independent expert advice on this research activity, as agreed with the EMA."