Swedish climate activist Greta Thunberg elbow bumps Mayor of Milan Giuseppe Sala during the Youth4Climate pre-COP26 conference in Milan, Italy, September 28, 2021. REUTERS/Flavio Lo Scalzo

Canada's opposition Conservative Party leader Erin O'Toole elbow-bumps with a supporter during a campaign stop in Oakville, Ontario, Canada September 19, 2021. REUTERS/Blair Gable

Canada's opposition Conservative party leader Erin O'Toole elbow-bumps with a youth at a rally during his election campaign tour, in Cambridge, Ontario, Canada September 18, 2021. REUTERS/Blair Gable

Canada's opposition Conservative party leader Erin O'Toole elbow-bumps his wife Rebecca on stage during his election campaign tour in St. Catharines, Ontario, Canada September 17, 2021. REUTERS/Blair Gable

Canada's opposition Conservative party leader Erin O'Toole elbow-bumps a supporter as he makes a stop during his election campaign tour in St. Catharines, Ontario, Canada September 17, 2021. REUTERS/Blair Gable

Canada's opposition Conservative party leader Erin O'Toole elbow-bumps with a person during a stop at a constituency office during his election campaign tour in Brantford, Ontario, Canada September 17, 2021. REUTERS/Blair Gable

Canada's opposition Conservative party leader Erin O'Toole elbow-bumps with a kid during a stop at a constituency office during his election campaign tour in Brantford, Ontario, Canada September 17, 2021. REUTERS/Blair Gable

Canada's Liberal Prime Minister Justin Trudeau elbow bumps a person during an election campaign stop in London, Ontario Canada September 17, 2021. REUTERS/Carlos Osorio

Britain's Prime Minister Boris Johnson and Netherlands' Prime Minister Mark Rutte elbow-bump each other outside Downing Street, in London, Britain, September 17, 2021. REUTERS/Peter Nicholls

Britain's Prime Minister Boris Johnson and Netherlands' Prime Minister Mark Rutte elbow-bump each other outside Downing Street, in London, Britain, September 17, 2021. REUTERS/Peter Nicholls

Britain's Prime Minister Boris Johnson bumps elbows with President of the Kurdistan region in Iraq Nechirvan Barzani on Downing Street, in London, Britain September 17, 2021. REUTERS/Peter Nicholls

Canada's Liberal Prime Minister Justin Trudeau elbow bumps with a supporter at an election campaign stop in Blainville, Quebec Canada September 16, 2021. REUTERS/Carlos Osorio

Canada's New Democratic Party (NDP) leader Jagmeet Singh bumps elbows with a girl during an election campaign visit in Toronto, Ontario, Canada September 16, 2021. REUTERS/Nick Lachance

Australian Defense Minister Peter Dutton (L) bumps elbows with South Korean Defense Minister Suh Wook (R) prior to their meeting a​t the Ministry of National Defense in Seoul, South Korea, September 13, 2021. Jeon Heon-kyun/Pool via REUTERS

Canada's Prime Minister Justin Trudeau bumps elbows with a man while visiting Paramount Fine Foods during his election campaign tour in Toronto, Ontario, Canada, September 10, 2021. REUTERS/Carlos Osorio

New Democratic Party leader Jagmeet Singh and the leader of the Bloc Quebecois Yves-Francois Blanchet bump elbows following the federal election French-language leaders debate, in Gatineau, Quebec, Canada September 8, 2021. Sean Kilpatrick/Pool via REUTERS

Canada's Liberal Prime Minister Justin Trudeau bumps elbows with a kid at a campaign stop during his election campaign tour, at Valbruna ASW Inc. in Welland, Ontario, Canada September 6, 2021. REUTERS/Carlos Osorio

Canada's Liberal Prime Minister Justin Trudeau elbow-bumps with a youngster during a campaign stop during his election campaign tour, at Valbruna ASW Inc. in Welland, Ontario, Canada September 6, 2021. REUTERS/Carlos Osorio

Canada's Liberal Prime Minister Justin Trudeau elbow bumps supporters during a campaign stop in his election campaign tour, in Newmarket, Ontario, Canada September 5, 2021. REUTERS/Carlos Osorio

Canada's Liberal Prime Minister Justin Trudeau and Deputy Prime Minister and Minister of Finance Chrystia Freeland elbow-bump during Trudeau's election campaign at the Metro Toronto Convention Centre in Toronto, Ontario, Canada September 1, 2021. REUTERS/Carlos Osorio

An Afghan refugee elbow bumps a U.S. Army officer before boarding a bus that will take refugees to a processing center, upon arrival at Dulles International Airport in Dulles, Virginia, U.S., August 31, 2021. REUTERS/Evelyn Hockstein

Canada's Liberal Prime Minister Justin Trudeau bumps elbows with an Iqaluit resident during an election campaign visit to Iqaluit, Nunavut, Canada August 30, 2021. REUTERS/Casey Lessard

Leader of the Conservative Party of Canada, Erin O'Toole, bumps elbow with a woman during a campaign stop at Dog Tales Rescue & Sanctuary in King City, Ontario, Canada on August 30, 2021. REUTERS/Carlos Osorio

Canada's Prime Minister Justin Trudeau bumps elbows with a person outside Nafisa Middle Eastern Cuisine restaurant during his election campaign tour in Mississauga, Ontario, Canada August 27, 2021. REUTERS/Carlos Osorio

German Chancellor Angela Merkel performs an elbow check with Director-General of the World Trade Organisation Ngozi Okonjo-Iweala next to President of the World Bank David Malpass during a meeting with economic and financial organizations in Berlin, Germany, August 26, 2021. Clemens Bilan/Pool via REUTERS

German Chancellor Angela Merkel performs an elbow check with African Development Bank (AfDB) President Akinwumi Adesina next to Managing Director of the International Monetary Fund (IMF) Kristalina Georgieva during a meeting with economic and financial organizations in Berlin, Germany, August 26, 2021. Clemens Bilan/Pool via REUTERS

French President Emmanuel Macron and Irish President Michael D. Higgins bump elbows as Macron visits Aras an Uachtarain, in Dublin, Ireland, August 26, 2021. REUTERS/Clodagh Kilcoyne/Pool

U.S. Special Representative for North Korea, Sung Kim leaves after talks to reporters at Plaza Hotel, in Seoul, South Korea August 23, 2021. Pool via REUTERS/Chung Sung-Jun

U.S. Special Representative for North Korea, Sung Kim (L) bumps elbows with Noh Kyu-duk (R), South Korea's Special Representative for Korean Peninsula Peace and Security Affairs, during their meeting at Plaza Hotel, in Seoul, South Korea August 23, 2021. Pool via REUTERS/Chung Sung-Jun

U.S. Special Representative for North Korea, Sung Kim (L) bumps elbows with Noh Kyu-duk (R), South Korea's Special Representative for Korean Peninsula Peace and Security Affairs, during their meeting at Plaza Hotel, in Seoul, South Korea August 23, 2021. Pool via REUTERS/Chung Sung-Jun

Justin Trudeau, Canadian Liberal Leader, elbow taps with a staff member at the Cows Creamery in Charlottetown, Prince Edward Island, Canada, August 22, 2021. REUTERS/John Morris

Canadian Liberal leader Justin Trudeau elbow taps with a young child during the 2021 election while visiting the riding of Malpeque in Cornwall, Prince Edward Island, Canada, August 22, 2021. REUTERS/John Morris

Canadian Liberal leader Justin Trudeau elbow taps in the riding of Malpeque in Cornwall, Prince Edward Island, Canada, August 22, 2021. REUTERS/John Morris

Justin Trudeau, Liberal leader of Canada, attempts to elbow tap with a young child during his visit of the riding of Malpeque in Cornwall, Prince Edward Island, Canada, August 22, 2021. REUTERS/John Morris

Prime Minister of North Rhine-Westphalia and candidate for chancellor of the CDU/CSU Armin Laschet elbow bumps German Chancellor Angela Merkel during a CDU/CSU campaign kick off ahead of the federal election at Tempodrom in Berlin, Germany, August 21, 2021. REUTERS/Annegret Hilse

Prime Minister of North Rhine-Westphalia and candidate for chancellor of the CDU/CSU Armin Laschet elbow bumps German Chancellor Angela Merkel as CSU party chief Markus Soeder claps during a CDU/CSU campaign kick off ahead of the federal election at Tempodrom in Berlin, Germany, August 21, 2021. REUTERS/Annegret Hilse

Japan’s Foreign Minister Toshimitsu Motegi elbow bumps his Iraqi counterpart Fuad Hussein in Baghdad, Iraq August 21, 2021. REUTERS/Saba Kareem

Canada's Liberal Prime Minister Justin Trudeau bumps elbows with a supporter as he arrives at the Marriott hotel before embarking on his first election campaign visit, in Ottawa, Ontario, Canada August 15, 2021. REUTERS/Lars Hagberg

Canada's Prime Minister Justin Trudeau bumps elbows with a supporter accompanied by his children Ella-Grace, Xavier and Hadrien before embarking on his first election campaign visit, in Ottawa, Ontario, Canada, August 15, 2021. REUTERS/Patrick Doyle

Canada's Prime Minister Justin Trudeau bumps elbows with a supporter before embarking on his first election campaign visit, in Ottawa, Ontario, Canada, August 15, 2021. REUTERS/Patrick Doyle

Canada's Prime Minister Justin Trudeau bumps elbows with a supporter before embarking on his first election campaign visit, in Ottawa, Ontario, Canada, August 15, 2021. REUTERS/Patrick Doyle

Tokyo 2020 Olympics - The Tokyo 2020 Olympics Closing Ceremony - Olympic Stadium, Tokyo, Japan - August 8, 2021. International Olympic Committee (IOC) President Thomas Bach bumps elbows with Rusila Nagasau of Fiji Pool via REUTERS/Dan Mullan

Tokyo 2020 Olympics - The Tokyo 2020 Olympics Closing Ceremony - Olympic Stadium, Tokyo, Japan - August 8, 2021. International Olympic Committee (IOC) President Thomas Bach taps elbows with Samuel Takyi of Ghana Pool via REUTERS/Dan Mullan

Tokyo 2020 Olympics - The Tokyo 2020 Olympics Closing Ceremony - Olympic Stadium, Tokyo, Japan - August 8, 2021. International Olympic Committee (IOC) President Thomas Bach wearing a protective face mask bumps elbows with Rusila Nagasau of Fiji wearing a protective face mask and representing the continent of Oceania during the closing ceremony REUTERS/Molly Darlington

Israeli President Isaac Herzog bumps elbows with Prime Minister Naftali Bennett, after he received a third dose of a coronavirus disease (COVID-19) vaccine at Sheba Medical Center in Ramat Gan, Israel, July 30, 2021. Maya Alleruzzo/Pool via REUTERS

Israeli President Isaac Herzog bumps elbows with Prime Minister Naftali Bennett, after he received a third dose of a coronavirus disease (COVID-19) vaccine at Sheba Medical Center in Ramat Gan, Israel, July 30, 2021. Maya Alleruzzo/Pool via REUTERS

International Olympic Committee (IOC) President Thomas Bach (L) elbow bumps with a child as he visits the Olympic Agora exhibition in Tokyo, Japan, July 30, 2021. REUTERS/Issei Kato/Pool

Britain's Prime Minister Boris Johnson greets members of the Nigerian delegation with elbow-bumps on the second day of the Global Education Summit in London, Britain July 29, 2021. Tolga Akmen/Pool via REUTERS

Canada's Prime Minister Justin Trudeau bumps elbows with Prince Edward Island Premier Dennis King at the daycare inside Carrefour de l'Isle-Saint-Jean school in Charlottetown, Prince Edward Island, Canada, July 27, 2021. REUTERS/John Morris

Tokyo 2020 Olympics - The Tokyo 2020 Olympics Opening Ceremony - Olympic Stadium, Tokyo, Japan - July 23, 2021. International Olympic Committee (IOC) President Thomas Bach and Tokyo 2020 President Seiko Hashimoto wearing protective face masks touch elbows during the opening ceremony REUTERS/Kai Pfaffenbach

Tokyo 2020 Olympics - The Tokyo 2020 Olympics Opening Ceremony - Olympic Stadium, Tokyo, Japan - July 23, 2021. International Olympic Committee (IOC) President Thomas Bach and Tokyo 2020 President Seiko Hashimoto touch elbows during the opening ceremony REUTERS/Kai Pfaffenbach

Tokyo 2020 Olympics - The Tokyo 2020 Olympics Opening Ceremony - Olympic Stadium, Tokyo, Japan - July 23, 2021. International Olympic Committee (IOC) President Thomas Bach and Tokyo 2020 President Seiko Hashimoto wearing protective face masks touch elbows during the opening ceremony as empty seats are seen in the background REUTERS/Kai Pfaffenbach

Tokyo 2020 Olympics - The Tokyo 2020 Olympics Opening Ceremony - Olympic Stadium, Tokyo, Japan - July 23, 2021. International Olympic Committee (IOC) President Thomas Bach and Tokyo 2020 President Seiko Hashimoto touch elbows as empty seats are seen in the background during the opening ceremony REUTERS/Kai Pfaffenbach

Tokyo 2020 Olympics - The Tokyo 2020 Olympics Opening Ceremony - Olympic Stadium, Tokyo, Japan - July 23, 2021. International Olympic Committee (IOC) President Thomas Bach and Tokyo 2020 President Seiko Hashimoto touch elbows during the opening ceremony REUTERS/Kai Pfaffenbach

U.S. Deputy Secretary of State, Wendy Sherman and South Korean Foreign Minister Chung Eui-yong elbow bump prior to their meeting at the foreign ministry in Seoul, South Korea, July 22, 2021. Sherman is visiting South Korea to discuss North Korea's nuclear program and other regional and global issues. Song Kyung-seok/Pool via REUTERS

Olympics - 138th IOC Session - Hotel Okura, Tokyo, Japan - July 21, 2021 President of the International Olympic Committee Thomas Bach (R) bumps elbows with members of the Brisbane 2032 delegation (L-R) John Coates AC, President, Australian Olympic Committee and The Honourable Annastacia Palaszczuk MP, Premier of Queensland and Minister for Trade, after Brisbane was announced as the 2032 Summer Olympics host city during the 138th IOC Session Pool via REUTERS/Toru Hanai

Olympics - 138th IOC Session - Hotel Okura, Tokyo, Japan - July 21, 2021 President of the International Olympic Committee Thomas Bach (R) bumps elbows with members of the Brisbane 2032 delegation (L-R) John Coates AC, President, Australian Olympic Committee and The Honourable Annastacia Palaszczuk MP, Premier of Queensland and Minister for Trade, after Brisbane was announced as the 2032 Summer Olympics host city during the 138th IOC Session Pool via REUTERS/Toru Hanai

U.S. Deputy Secretary of State Wendy Sherman elbow bumps with Japanese Vice-Minister for Foreign Affairs Takeo Mori prior to their meeting at the Iikura Guesthouse in Tokyo, Japan, July 20, 2021, Eugene Hoshiko/Pool via REUTERS

Israeli Prime Minister Naftali Bennett (R) elbow-bumps Alternate Prime Minister and Foreign Minister Yair Lapid (L) before the start of the weekly cabinet meeting at the Knesset in Jerusalem July 19, 2021. Gil Cohen-Magen/Pool via REUTERS

Revellers dance during the "00:01" event organised by Egyptian Elbows at Oval Space nightclub, as England lifted most coronavirus disease (COVID-19) restrictions at midnight, in London, Britain, early July 19, 2021. REUTERS/Natalie Thomas