People receive a dose of the Pfizer-BioNTech COVID-19 vaccine during a vaccination event in the Cologne Cathedral on Christmas Eve amid the coronavirus disease (COVID-19) pandemic in Cologne, Germany, December 24, 2021. REUTERS/Thilo Schmuelgen

RM2HC4DT4–People receive a dose of the Pfizer-BioNTech COVID-19 vaccine during a vaccination event in the Cologne Cathedral on Christmas Eve amid the coronavirus disease (COVID-19) pandemic in Cologne, Germany, December 24, 2021. REUTERS/Thilo Schmuelgen

people check in their paperwork l during the vaccination action at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant hits Europe (Photo by Ying Tang/NurPhoto)

RM2KCYE06–people check in their paperwork l during the vaccination action at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant hits Europe (Photo by Ying Tang/NurPhoto)

FILE - General Secretary of the Social Democratic Party Lars Klingbeil talks during the election campaign in Cologne, Germany, Sept. 24, 2021. SPD party co-leader Walter-Borjans, 69, announced recently that he won't seek re-election when his terms expires in December. On Monday, top party officials proposed that Lars Klingbeil, the party's general secretary since 2017, replace Walter-Borjans as Esken's co-leader. (AP Photo/Martin Meissner, File)

RM2MD36C9–FILE - General Secretary of the Social Democratic Party Lars Klingbeil talks during the election campaign in Cologne, Germany, Sept. 24, 2021. SPD party co-leader Walter-Borjans, 69, announced recently that he won't seek re-election when his terms expires in December. On Monday, top party officials proposed that Lars Klingbeil, the party's general secretary since 2017, replace Walter-Borjans as Esken's co-leader. (AP Photo/Martin Meissner, File)

RF2HGKDT8–Cologne, Germany - December 24, 2021: a tanker sails on the rhine through the old town of cologne

People queue to receive a dose of the Pfizer-BioNTech COVID-19 vaccine during a vaccination event in the Cologne Cathedral on Christmas Eve amid the coronavirus disease (COVID-19) pandemic in Cologne, Germany, December 24, 2021. REUTERS/Thilo Schmuelgen

RM2HC4DT1–People queue to receive a dose of the Pfizer-BioNTech COVID-19 vaccine during a vaccination event in the Cologne Cathedral on Christmas Eve amid the coronavirus disease (COVID-19) pandemic in Cologne, Germany, December 24, 2021. REUTERS/Thilo Schmuelgen

people waits in a long line in front of a coronavirus test center at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant (Photo by Ying Tang/NurPhoto)

RM2KCYE0Y–people waits in a long line in front of a coronavirus test center at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant (Photo by Ying Tang/NurPhoto)

RM2HC4DT6–People queue to receive a dose of the Pfizer-BioNTech COVID-19 vaccine during a vaccination event in the Cologne Cathedral on Christmas Eve amid the coronavirus disease (COVID-19) pandemic in Cologne, Germany, December 24, 2021. REUTERS/Thilo Schmuelgen

people are seen being administed vaccination inside Dom Cathedral during the vaccination action at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant hits Europe (Photo by Ying Tang/NurPhoto)

RM2KCYE0H–people are seen being administed vaccination inside Dom Cathedral during the vaccination action at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant hits Europe (Photo by Ying Tang/NurPhoto)

A man receives a dose of the Pfizer-BioNTech COVID-19 vaccine during a vaccination event in the Cologne Cathedral on Christmas Eve amid the coronavirus disease (COVID-19) pandemic in Cologne, Germany, December 24, 2021. REUTERS/Thilo Schmuelgen

RM2HC4DD4–A man receives a dose of the Pfizer-BioNTech COVID-19 vaccine during a vaccination event in the Cologne Cathedral on Christmas Eve amid the coronavirus disease (COVID-19) pandemic in Cologne, Germany, December 24, 2021. REUTERS/Thilo Schmuelgen

a vaccination sign is seen in front of Dom Cathedral during the vaccination action at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant hits Europe (Photo by Ying Tang/NurPhoto)

RM2KCYE0W–a vaccination sign is seen in front of Dom Cathedral during the vaccination action at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant hits Europe (Photo by Ying Tang/NurPhoto)

RM2HC4E04–People queue to receive a dose of the Pfizer-BioNTech COVID-19 vaccine during a vaccination event in the Cologne Cathedral on Christmas Eve amid the coronavirus disease (COVID-19) pandemic in Cologne, Germany, December 24, 2021. REUTERS/Thilo Schmuelgen

people waits in a long line in front of Dom Cathedral during the big vaccination action at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant (Photo by Ying Tang/NurPhoto)

RM2KCYE0X–people waits in a long line in front of Dom Cathedral during the big vaccination action at Christmas eve in Cologne, Germany on December 24, 2021 to speed up vaccination to cope with new Omicron variant (Photo by Ying Tang/NurPhoto)