• Some people have a higher genetic risk for Alzheimer’s disease
• People with Alzheimer’s often report depression and various sleep problems, like insomnia
• Researchers, however, found no evidence that sleep-related characteristics or depression cause Alzheimer’s

Disturbed sleep doesn’t cause Alzheimer’s disease, but some sleep patterns may be more common in people who have a high genetic risk for it, a new study reports.

Those patterns include being a morning person, having shorter sleep duration and being less likely to have insomnia, according to findings published in the August online issue of the journal Neurology.

“We know that people with Alzheimer’s disease often report depression and various sleep problems, like insomnia,” said study author Dr Abbas Dehghan, of the faculty of medicine at Imperial College London in the UK “We wanted to find out if there are causal relationships between different sleep patterns and depression and Alzheimer’s.”

Risk based on genetic studies

His team analysed a number of genetic studies. One compared nearly 22 000 people with Alzheimer’s to nearly 42 000 others. Another compared more than 9 200 people with major depression to more than 9 500 without it. Another assessed sleep-related characteristics of more than 446 000 people.

Alzheimer’s risk was determined based on genetic studies where the disease was diagnosed by autopsy or clinical examination.

Researchers found no evidence that sleep-related characteristics caused Alzheimer’s. They also found no evidence of cause and effect between major depression and Alzheimer’s.

The study did find some small associations between sleep habits and Alzheimer’s. Specifically, people with twice the genetic risk for Alzheimer’s were 1% more likely than others to be morning people, and people with twice the genetic risk of Alzheimer’s had a 1% lower risk of insomnia.

Researchers emphasised that these associations are small and do not prove cause and effect.

They also noted that most of the people in the study were of European ancestry, so the results may not apply to other racial/ethnic groups.

^{Image credit: Pexels}

• Worldwide, tens of millions of people may avoid Covid-19 vaccination
• People who had the least faith in their governments were most unlikely to accept a vaccine
• Scientists are aiming to appear in a series of videos on social media to help raise public confidence 

Scientists called for urgent action to improve public trust in immunisation as research suggested sizeable minorities in some nations may be reluctant to be vaccinated against Covid-19.

With few effective treatments and no cure for the coronavirus, companies and governments are racing to develop vaccines in a bid to arrest the pandemic.

But there is increasing concern that “vaccine hesitancy” is also on the rise, with misinformation and mistrust colouring people’s acceptance of scientific advances.

A call to action

In a new study published in Nature Medicine, researchers in Spain, the United States and Britain surveyed 13 400 people in 19 countries hit hard by Covid-19 and found that while 72% said they would be immunised, 14% would refuse and another 14% would hesitate.

When extrapolated across whole populations this could amount to tens of millions of people who may avoid vaccination, the authors said.

“These findings should be a call to action for the international health community,” said co-author Heidi Larson, who runs the Vaccine Confidence Project at London School of Hygiene and Tropical Medicine.

“If we do not start building vaccine literacy and restoring public trust in science today, we cannot hope to contain this pandemic.”

Researchers found that people who had least faith in their governments were less likely to accept a vaccine – and even those who had been ill with the virus were not more likely to respond positively.

While in China 87% of respondents said they would take “a proven, safe and effective vaccine”, the highest of all the countries surveyed, the proportion dipped to 75% in the US and was as low as 55% in Russia.

“We found that the problem of vaccine hesitancy is strongly related with a lack of trust in government,” said study coordinator Jeffrey Lazarus, of the Barcelona Institute for Global Health.

Older people more likely to accept vaccine

When asked if they would accept an approved, safe vaccine recommended “by your employer” only 32% of respondents completely agreed.

Acceptance rates again varied widely by country, with China again having the most clearly positive responses (84% either completely or somewhat agreed) and Russia with the least (27%).

The study, released at the Union World Conference on Lung Health, found greater acceptance of vaccines among people earning more than $32 (R525) a day.

They also found older people were more likely to accept a vaccine than those under 22.

In a new initiative supported by the US and Vaccine Alliance Gavi, scientists involved in vaccine development will appear in a series of videos on social media to help raise public confidence in their work.

The researchers and clinicians in the UK, USA, South Africa, India and Brazil will be posting under the hashtag #TeamHalo – a reference to the circle of global scientific endeavour – on TikTok, Twitter and Instagram.

Trump biggest driver of misinformation

“I’m used to spending time pipetting samples and analysing data,” said Anna Blakney, a participating bioengineer who is part of the vaccine development team at Imperial College in London.

“TikTok is a new frontier for me but I’m enthusiastic about demystifying our work and making it accessible to the world.”

Earlier this month, a study in the journal Royal Society Open Science found up to a third of people in some countries may believe coronavirus misinformation and in turn be less open to immunisation.

And recent research from Cornell University found that US President Donald Trump was the world’s biggest driver of Covid-19 misinformation, because of his promotion of what the researchers termed “miracle cures”.

Meanwhile, the speed of development has caused concerns in some countries, with Russia’s announcement in August that it would begin roll-out of the Sputnik V vaccine before crucial phase 3 trials criticised as premature.

^{Image credit: Unsplash}