One of the classic symptoms of narcolepsy is being extremely tired during the day.

Children who got narcolepsy after the swine flu vaccine struggle with obesity and depression

“This is a lifelong and serious disease,” one researcher says.

In the aftermath of the 2009-2010 swine flu pandemic, reports of a disturbing trend came from Sweden and Finland.

A number of children who had been given the new vaccine Pandemrix had contracted a sleep disorder called narcolepsy.

In Norway, doctors begun to notice the same thing.

The affected people didn’t just develop the familiar, characteristic symptoms of the disease, according to paediatrician Sebjørg Elizabeth Hesla Nordstrand from Oslo University Hospital.

She recently completed her doctoral degree on Norwegians who developed narcolepsy after receiving the swine flu vaccine.

Her results show that many of those who developed narcolepsy — especially children — also developed other problems. Many became overweight or obese and a number struggled with depression and other mental illnesses.

“This is a lifelong and serious disease where many people unfortunately develop psychiatric symptoms as well as obesity and depression,” Nordstrand says.

Around 350 Norwegians developed narcolepsy

It’s still not known exactly how many Norwegians developed narcolepsy as a side effect of the swine flu vaccine, Nordstrand says.

She and her colleagues have so far identified 195 people who developed the disease after the pandemic. But she estimates that around 350 people developed the sickness.

Most had gotten the vaccine, but some had not. And some of those who became ill, may have been infected with the swine flu virus before receiving the vaccine.

Lill Trogstad, a medical doctor and researcher at the Norwegian Institute of Public Health, has previously told that people who got both the swine flu and the vaccine may have had a greater risk of developing narcolepsy.

Ten years after the swine flu pandemic, it’s still a mystery as to which vaccine ingredient was involved in triggering narcolepsy. But there is virtually no one who doubts that narcolepsy was a side effect of the Pandemrix vaccine, according to Nordstrand.

A total of 2.2 million Norwegians took the Pandemrix vaccine, according to the Norwegian Medicines Agency.

High BMI

Many people who developed narcolepsy were also either overweight or obese, one of Nordstrand’s studies showed.

In this study, the researchers examined the BMI of 91 children and adults who contracted the disease after 2009.

Among girls, as many as 70 per cent were overweight or obese. This is much higher than what is typical among their healthy peers, where the proportion is 15 per cent.

However, the study didn’t provide any answers as to why this was the case.

“It didn’t matter how long the children had been ill or how serious their narcolepsy was. But we saw that individuals who had one or more medical conditions in addition to narcolepsy were more likely to be overweight or obese,” Nordstrand said.

Sebjørg Elizabeth Hesla Nordstrand has studied how individuals who developed narcolepsy after the swine flu pandemic are doing.

Less active?

Researchers in Sweden have seen the same trend: adolescents with narcolepsy have a high BMI. Professor Maria Engström says that they tried to figure out why this was the case.

Using MRI scans, they found that the fat composition in narcolepsy patients was slightly different than in healthy individuals. But more research is needed to understand why.

Another theory is that young people with narcolepsy might have been less active than healthy young people, and therefore were prone to put on weight.

But there was nothing in the Swedish study to suggest this was true.

“We measured the degree of physical activity one week before the MRI. We found no difference between patients and others based on several different measurements of daily activity, such as total energy consumption,” Engström wrote in an email to

Psychiatric symptoms common

Norwegians who developed narcolepsy after taking the swine flu vaccine also often had psychiatric symptoms, Nordstrand and her colleagues reported in another study.

Thirty-eight per cent of children and 33 per cent of adults had psychiatric symptoms that were serious enough to be cause for clinical concern.

“Internalizing difficulties were the most common, such as symptoms of depression, anxiety and physical ailments,” Nordstrand said.

Symptoms of narcolepsy

  • Falling asleep at inopportune times, and extreme tiredness during the day.
  • Broken sleep at night, with frequent awakenings.
  • Loss of muscle strength when experiencing strong emotions, as if in a dream state, only the individual is awake (cataplexy).
  • Hallucinations when the person is about to wake up or fall asleep.
  • Muscle paralysis when the person is about to wake up or fall asleep.
  • These are the most common symptoms. Some people experience them all, while others only experience a subset.

Source: Sebjørg Elizabeth Hesla Nordstrand

Better quality of life after two years

An positive finding in Nordstrand's doctoral research concerned how people with narcolepsy perceived their lives.

Their quality of life had improved over time.

This was at least true for the 31 patients who participated in this study.

The researchers examined how the patients felt shortly after their diagnosis and followed up this examination two years later.

The drug sodium oxybate (Xyrem) may have played a role here.

The medicine helps people with many classic narcolepsy symptoms, such as daytime sleepiness, poor night’s sleep, and also the special bouts of muscle paralysis that people with narcolepsy can develop when they experience strong emotions, such as laughing or getting angry.

The researchers found a connection between improvements in quality of life and the use of sodium oxybate.

Hope for improvement

Nordstrand also points out that knowledge about narcolepsy is skyrocketing.

“We are diagnosing the disease earlier, we know more about it, and there are better and better medications for treatment,” she says.

At the same time, she believes it’s important that children and adults with narcolepsy are followed up by interdisciplinary teams.

“The team should consist of a nurse, an adult or child neurologist, a nutritionist, a sociologist and a psychologist or psychiatrist. The school must also be involved, including the school nurse,” says Nordstrand.

She believes it’s very important that everyone who helps or treats children and adults with narcolepsy know that the disease can involve more than just sleepiness.

Monitoring of side effects far better today

In an article on their website (in Norwegian), the Norwegian Medicines Agency asks the question “Side effects from vaccines – what did we learn from the pandemic in 2009?”.

A lot is different today compared to then, the Agency writes- For example the monitoring of side effects today is far better.

The Pandemrix vaccine was based on a well-tested vaccine, the Agency writes. The swine flu virus was added to the already known vaccine, a strategy that was considered safe based on the amount of knowledge and long experience with flu vaccines, says Steinar Madsen, Medical Director at the Norwegian Medicines Agency.

That narcolepsy might be a side effect from the vaccine was not discovered until after the vaccination was largely over in March 2010.

According to Madsen, active monitoring of side effects while a vaccine is being administered is very important.

“Today, we are able to collect and analyze data from different health registries. This means that new, unexpected or serious side effects will be discovered sooner”, he says.

Important to be open about side effects

Norway was one of the first countries to report on rare and serious side effects from the AstraZeneca Covid vaccine recently. Some have said that this is due to the country’s excellent health registries and system for monitoring side effects.

Rare side effects are hard to discover, the Agency writes. Even with thorough studies, you can never safeguard against rare side effects. Openness and balanced information about risk-benefit assessments is therefore imperative.

“We have to be open about side effects from vaccines”, Steinar Madsen says in the article. “Not just that which is reported during the vaccination, but also what we know and what we don’t know about the vaccines before we start using them”, he says.

Translated by Nancy Bazilchuk


Sebjørg E. H. Nordstrand et al.: Obesity and other medical comorbidities among NT1 patients after the Norwegian H1N1 influenza epidemic and vaccination campaign, Sleep, 2019. Summary

Sebjørg E. H. Nordstrand et al.: Psychiatric symptoms in patients with post-H1N1 narcolepsy type 1 in Norway, Sleep, 2019.

Sebjørg E. H. Nordstrand et al.: Changes in quality of life in individuals with narcolepsy type 1 after the H1N1 influenza epidemic and vaccination campaign in Norway: a two-year prospective cohort study, Sleep Medicine, 2018. Summary

Natasha Morales Drissi et al.: Unexpected Fat Distribution in Adolescents With Narcolepsy, Frontiers in Endocrinology, 2020.


Read the Norwegian version of this article at

Powered by Labrador CMS