High levels of COVID-19 immunity have been found in the residents of an Austria ski resort that was at the centre of Europe's pandemic.
A study of residents in the ski resort of Ischgl which, was the site of Austria's worst coronavirus outbreak, found that at least eight months after contracting the virus the vast majority of people remained immune.
The findings provide more insight into how long immunity lasts after infection, and also suggest that herd immunity may start to kick in earlier than widely believed, the team behind the study said.
The ski resort is believed to have heavily contributed to Europe's first wave with hundreds being infected before governments had realised the coronavirus was already present in their countries.
In April last year more than 600 infections in Austria were linked to the area and possibly twice as many people who visited from outside the country could have been affected.
The discovery of such a high amount of cases made Ischgl notorious after its contribution to Europe's pandemic was realised.
In normal times the resort attracts millions of visitors and has a reputation for as being the 'Ibiza of the Alps'.
The need to keep warm indoors, excessive drinking and partying, and mingling of people from numerous different countries created the perfect breeding ground for the virus.
Andrea Ammon, director of the European Centre for Disease Prevention and Control, has said in the past skiers returning home after their winter holiday will be recorded as a key moment in the history of the pandemic.
Austria's main public health agency AGES believes the Ischgl outbreak, in which thousands of people from across Europe were infected, began in February last year, before the first cases in Austria were detected.
The Medical University of Innsbruck conducted a study in April that found 42% of Ischgl's population had antibodies for the virus.
A follow-up study conducted in November and published on Thursday found the vast majority of those who had antibodies in the first study still had them in the second.
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"In close to 90% of those who tested seropositive in April, antibodies could also be detected in November," virologist Dorothee van Laer, one of the scientists who carried out the study, said in a statement.
The study involved just over 900 people, 801 of whom took part in the first one.
"Despite a slight fall in the concentration of antibodies we can say that immunity is relatively stable," she added.
The university said its study was one of the biggest of its kind and over one of the longest periods, helping to answer the question of how long immunity lasts after infection.
It also suggests herd immunity starts to kick in sooner than many have suggested, since Ischgl had a much smaller second wave of infections in November than comparable towns in the region.
"It seems that this immunity situation, which was somewhere between 40 and 50% (of the population) in November actually protected the population from infection," van Laer told a news conference, adding that basic social distancing measures were in place then, like face masks being required and bars being shut.
The Austrian government is being sued over claims it failed to lock down the Tyrolean resort properly at the start of the outbreak.
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