He explained that the decision to allow crowds back into stadiums depended on more than just the prevalence of coronavirus, but which variant was dominant, as well as the hospital capacity at the time.
He explained: “I’m very hopeful the country will be vaccinated.
“And I’m confident the game will go ahead.
“I’m not confident about how many people will get to see it live.
England will play Scotland in the UEFA Euro on June 18 as part of the group stages of the competition.
Scotland and England are in Group D along with Croatia and Czech Republic.
The game is due to be played at Wembley Stadium.
As it stands, the Euro matches will not be played in one host country, but across the continent.
When discussing travel to games, Professor Leitch said: “ I don’t think they’ll be much international travel except or the exempt groups like elite sports people.
“I don’t think they’ll be much away support on the continent or vice versa.”
Current Coronavirus guidelines restrict travel between local authority areas unless essential.
People are asked to remain in their homes unless leaving for essential shopping, care reasons or exercise.
On Saturday, 994 new positive cases were recorded, and 60 people reportedly died after testing positive for the virus.
543,370 people have received the first dose of the Covid vaccination and 7,638 have received their second dose.