Detroit nurse Hollie Macias converses with Shanya Taylor, 19, before she receives her coronavirus disease (COVID-19) vaccine at a mobile pop-up vaccination clinic hosted by the Detroit Health Department with the Detroit Public Schools Community District at East English Village Preparatory Academy in Detroit, Michigan, U.S., July 21, 2021. REUTERS/Emily Elconin

Detroit nurse Hollie Macias walks past an empty waiting area set up for people after receiving their coronavirus disease (COVID-19) vaccines at a mobile pop-up vaccination clinic hosted by the Detroit Health Department with the Detroit Public Schools Community District at East English Village Preparatory Academy in Detroit, Michigan, U.S., July 21, 2021. REUTERS/Emily Elconin

Athletics - British Athletics Championships - Manchester Regional Arena, Manchester, Britain - June 26, 2021 Britain’s Holly Bradshaw in action during the women's Pole Vault final Action Images via Reuters/Molly Darlington

Athletics - British Athletics Championships - Manchester Regional Arena, Manchester, Britain - June 26, 2021 Britain’s Holly Bradshaw celebrates after winning the women's Pole Vault final and a new National Record Action Images via Reuters/Molly Darlington

Athletics - British Athletics Championships - Manchester Regional Arena, Manchester, Britain - June 26, 2021 Britain’s Holly Bradshaw celebrates after winning the women's Pole Vault final and a new National Record Action Images via Reuters/Molly Darlington

Athletics - British Athletics Championships - Manchester Regional Arena, Manchester, Britain - June 26, 2021 Britain’s Holly Bradshaw reacts after winning the women's Pole Vault final and a new National Record Action Images via Reuters/Molly Darlington

Athletics - British Athletics Championships - Manchester Regional Arena, Manchester, Britain - June 26, 2021 Britain’s Holly Bradshaw in action during the women's Pole Vault final Action Images via Reuters/Molly Darlington

Athletics - British Athletics Championships - Manchester Regional Arena, Manchester, Britain - June 26, 2021 Britain’s Holly Bradshaw celebrates after winning the women's Pole Vault final and a new National Record Action Images via Reuters/Molly Darlington

Athletics - British Athletics Championships - Manchester Regional Arena, Manchester, Britain - June 26, 2021 Britain’s Holly Bradshaw in action during the women's Pole Vault final Action Images via Reuters/Molly Darlington

Athletics - British Athletics Championships - Manchester Regional Arena, Manchester, Britain - June 26, 2021 Britain’s Holly Bradshaw in action during the women's Pole Vault final Action Images via Reuters/Molly Darlington TPX IMAGES OF THE DAY

Athletics - British Athletics Championships - Manchester Regional Arena, Manchester, Britain - June 26, 2021 Britain's Holly Archer, Revee Walcott-Nolan, Erin Wallace and Katie Snowden in action during the women's 1500 metres final Action Images via Reuters/Molly Darlington

Horse Racing - Royal Ascot - Ascot Racecourse, Ascot, Britain - June 15, 2021 Hollie Doyle celebrates on Amtiyaz after winning the 18:10 Copper Horse Stakes Action Images via Reuters/Andrew Boyers

Horse Racing - Royal Ascot - Ascot Racecourse, Ascot, Britain - June 15, 2021 Amtiyaz ridden by Hollie Doyle on their way to winning the 18:10 Copper Horse Stakes Action Images via Reuters/Andrew Boyers

Horse Racing - Derby Festival - Epsom Downs Racecourse, Epsom, Britain - June 4, 2021 Corazon Espinado ridden by Hollie Doyle go on to win the 2:35 Coral ‘Beaten By A Length’ Free Bet Handicap Action Images via Reuters/Peter Cziborra

Athletics - Diamond League - Doha - Suhaim bin Hamad Stadium, Doha, Qatar - May 28, 2021 Holly Bradshaw of Britain in action during the Women's Pole Vault Final REUTERS/Ibraheem Al Omari

Holly Elson, Visitor Programmes Manager at Royal Botanic Gardens, poses for a photograph in the hedgerow 'plantscape' exhibit of the Secret World of Plants festival, at the Kew Gardens in London, Britain, May 6, 2021. REUTERS/John Sibley

Members of The King's Troop Royal Horse Artillery fire a gun salute to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Members of The King's Troop Royal Horse Artillery prepare to fire a gun salute to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Members of The King's Troop Royal Horse Artillery prepare to fire a gun salute to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Members of The King's Troop Royal Horse Artillery prepare to fire a gun salute to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Gun salute is fired by The King's Troop Royal Horse Artillery to mark the death of Britain's Prince Philip, husband of Queen Elizabeth, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

A member of The King's Troop Royal Horse Artillery places empty shells into boxes in advance of a gun salute to commemorate the death of Britain's Prince Philip, Duke of Edinburgh, at the Parade Ground, Woolwich Barracks in central London, Britain April 10, 2021. Hollie Adams/Pool via REUTERS

Holly Archer, 34, is monitored after receiving her coronavirus disease (COVID-19) vaccine as vaccine eligibility expands to anyone over the age of 16 at the Bradfield Community Center through Health Partners of Western Ohio in Lima, Ohio, U.S., March 29, 2021. REUTERS/Megan Jelinger

Holly Archer, 34, is monitored after receiving her coronavirus disease (COVID-19) vaccine as vaccine eligibility expands to anyone over the age of 16 at the Bradfield Community Center through Health Partners of Western Ohio in Lima, Ohio, U.S., March 29, 2021. REUTERS/Megan Jelinger

Britain's Chief Medical Officer for England Chris Whitty gives an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

The view from behind the lectern at the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

The view from behind the lectern at the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

The view from behind the lectern at the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty gives an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

General view of the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

General view of the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

General view of the new Downing Street Briefing Room after of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Medical Officer for England Chris Whitty, Britain's Prime Minister Boris Johnson and Britain's Chief Scientific Adviser Patrick Vallance give an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Chief Scientific Adviser Patrick Vallance gestures as he gives an update at a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

Britain's Prime Minister Boris Johnson holds a news conference on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS

General view of the new Downing Street Briefing Room ahead of an update by Britain's Prime Minister Boris Johnson on the coronavirus disease (COVID-19) pandemic, in London, Britain March 29, 2021. Hollie Adams/Pool via REUTERS