Sniffer dogs Miina, left, and K'ssi at the Helsinki airport in Vantaa, Finland, Wednesday Sept. 22, 2020. Finland has deployed coronavirus-sniffing dogs at the Nordic country’s main international airport in a four-month trial of an alternative testing method that could become a cost-friendly way to identify infected travelers. (Antti Aimo-Koivisto/Lehtikuva via AP)

Sniffer dog E.T. with trainer Anette Kare at the Helsinki airport in Vantaa, Finland, Wednesday Sept. 22, 2020. Finland has deployed coronavirus-sniffing dogs at the Nordic country’s main international airport in a four-month trial of an alternative testing method that could become a cost-friendly way to identify infected travelers. (Antti Aimo-Koivisto/Lehtikuva via AP)

Sniffer dog K'ssi at the Helsinki airport in Vantaa, Finland, Wednesday Sept. 22, 2020. Finland has deployed coronavirus-sniffing dogs at the Nordic country’s main international airport in a four-month trial of an alternative testing method that could become a cost-friendly way to identify infected travelers. (Antti Aimo-Koivisto/Lehtikuva via AP)

Sniffer dogs named K'ssi, left and Miina react with trainer Susanna Paavilainen at the Helsinki airport in Vantaa, Finland, Tuesday, Sept. 22, 2020. Four corona sniffer dogs are trained to detect the Covid-19 virus from the arriving passengers samples at the airport. (Antti Aimo-Koivisto/Lehtikuva via AP)