Researchers have begun looking for solutions outside of rapid testing to bring back some level of social normalcy as the pandemic continues to impact travel and large social events. In Finland scientists from the University of Helsinki have begun testing the use dogs that have been trained to sniff out SARS-CoV-2 infections in airports, positioning four different breeds at Helsinki Airport, the country's main international airport.

The dogs were trained by Finland's Smell Detection Association as part of a government-back trial to test what could become a cost-effective alternative to testing kits. A similar trial was conducted over the summer by the United Arab Emirates, with coronavirus sniffing canines stationed at Dubai International Airport. Other countries, including Australia, France, Germany and the United States are also studying the use of dogs to detect the coronavirus, by Finland's trial is the largest initiated so far.

"If it works, it will be a good screening method at any other places," said Anna Hielm-Bjorkman, Professor of Equine and Small Animal Medicine at the University of Helsinki and study lead, quoted by the Associated Press.

This is not the first study to test a dog's ability to sniff out coronavirus infections. In a study published back in July, researchers from the University of Veterinary Medicine Hannover, the Hannover Medical School and the German Armed Forces concluded that properly trained canines were able to discriminate between human saliva samples infected with the coronavirus and other samples with 94% accuracy.

Maren von Koeckritz Blickwede, professor at the University of Veterinary Medicine Hannover and the study's lead, believes that dogs are able to smell the change in metabolic processes of an infected person. In the past, dogs have been trained to smell other infectious diseases as well as cancers with great success.

"We think that the dogs are able to detect a specific smell of the metabolic changes that occur in [infected] patients," Blickwede stated, quoted by CNBC.

For the Helsinki Airport study, dogs will not come in direct contact with travelers. The voluntary program asks travelers to wipe their hand with a sample cloth and place the cloth in a jar. The jar will then be given to a coronavirus-sniffing trained dog in a separate booth with its handler.

It takes the canine about 10 seconds to detect whether the sample is positive or not, with the dog trained to give indications like laying down or barking. The entire test is designed to take no long than a minute.

The scientists in the Finnish study, as well as other global researchers, hope that dogs will eventually be able to be deployed at large social gatherings like concerts or sporting events to sniff out infected individuals before they enter the venue, thus preventing future outbreaks without the need for massive testing infrastructures.