Take a vaccine developed in haste? Never again, says Meissa Chebbi, who, like hundreds of other young Swedes suffered debilitating narcolepsy after a mass vaccination campaign against the 2009-2010 swine flu pandemic.
The experience has shaken Swedes' confidence in any future vaccine against the new coronavirus, compounding fears about unknown long-term side effects.
"I will never recommend that," 21-year-old Chebbi told AFP when asked about taking a speedily developed vaccine. "Unless you really have to take it because of life-threatening circumstances."
The Swedish case highlights the complex task governments face in rolling out vaccines against the coronavirus, especially at a time when rabid social media misinformation is feeding scepticism in state institutions and even about the disease itself.
The trauma over vaccines is particularly notable in Sweden, which normally boasts the participation of more than 90 per cent in its voluntary children's vaccination programme.
But a recent survey conducted by the Novus polling institute suggested that 26 per cent of Swedes do not plan to take any of the Covid-19 vaccines being developed and 28 per cent are undecided.
Forty-six per cent said they would get a jab.
Of those opposed, 87 per cent said it was due to fears over as-yet-unknown side effects.
Health authorities in the Scandinavian country in 2009 urged the public to voluntarily take the Pandemrix vaccine against swine flu, made by British drug company GlaxoSmithKline.
More than 60 per cent heeded the call -- the highest level in the world.
But Chebbi and hundreds of others, primarily children and young adults under 30, were later diagnosed with narcolepsy as a side effect of the vaccine.
A link was eventually established to an adjuvant, or booster, in the Pandemrix vaccine which was intended to strengthen the immune response.
Narcolepsy is a chronic disorder of the nervous system that causes excessive and often uncontrollable drowsiness.
"I have sleep attacks all the time in all kinds of situations and at inappropriate times... In my food, at job interviews, at lectures, seminars, at university. I've fallen asleep at my workplace, I fall asleep on buses and everywhere," Chebbi says.
"It has destroyed my life."
The Swedish Pharmaceutical Insurance has so far approved 440 of 702 narcolepsy claims linked to Pandemrix, paying out a total of 100 million kronor (9.8 million euros, $11.6 million) in compensation.
Anders Tegnell, Sweden's state epidemiologist and the face of the country's controversial 'softer' response to the new coronavirus, was among a group of experts at the Board of Health who called for the mass vaccination in 2009-2010.
"Of course the decision would have been completely different if we had known about the side effects. But they were completely unknown, they were a surprise to everybody," Tegnell told AFP in an interview.
"There has been an international consensus for many years that the best thing to do during a pandemic is to vaccinate, and that's really the only long-term solution we have."
Babis Stefanides, a 36-year-old Stockholm resident, said he's too wary to take a Covid jab.
"I'm not planning to take the vaccine," he told AFP. "There are just too many questions."
Tegnell said he understood Swedes' concerns.
"Of course when you have a new vaccine that we don't know very much about yet -- against a disease that we don't know very much about -- everybody ... wants to have more information before they make a decision on this," he said.
"We are going to inform about these vaccines when we know a little bit more about them."
Tegnell ruled out making any future vaccine mandatory.
According to the director of the Swedish Public Health Agency, Johan Carlson, 60 to 70 per cent of the population would have to be vaccinated in order to stop the spread of the virus.
"Everyone needs to have a think and decide what to do. Usually in Sweden, most people end up getting vaccinated," Carlson told Swedish Television on Sunday.
In a bid to assuage fears, Sweden plans to set up a register to quickly detect any side effects from a future Covid vaccine.
Hannah Laine, a 37-year-old social worker in Stockholm, said she, her husband and their three kids would definitely be getting the vaccine -- despite her fears.
"If it's approved for the market and we notice that the public health agency and society is saying that we should take the vaccine, we'll do it," she told AFP.
"We have to take our moral responsibility for the elderly and the sick. We'll take it, maybe not for our sake but for society's."
That kind of thinking worries Elisabeth Widell, chairperson of the Narcolepsy Association.
She says health authorities were not wrong to call for mass vaccination in 2009, but they appealed too heavily to Swedes' sense of solidarity and she hopes they won't do that again.
"People who choose not to get vaccinated should not be blamed and shamed. Because it's not mandatory, which means it's a free choice."
She urged Swedes to "do your own risk and benefit analysis".
Narcolepsy sufferer Chebbi remains determined.
"I'm not going to take the (Covid) vaccine until after about five years when we know what the risks are."