More than 50 bus routes in Toronto, as well as the Bloor-Danforth subway line, will be impacted by service changes starting Monday as a result of staffing shortages caused by the TTC's COVID-19 vaccine mandate.

Earlier this week the transit agency announced that it will be reducing service on several routes across the city next week. The TTC attributed the changes to a potential shortage of operators as a result of their new vaccination policy.

Employees had until Saturday to get both doses of the COVID-19 vaccine before being placed on unpaid leave. Those who choose not to comply with the policy by Dec. 31 could be fired.

The transit agency said that as of Nov. 21, about 92 per cent of the TTC's 15,061 employees have shared their vaccination status. The "vast majority" are fully vaccinated, officials said.

In a statement, TTC CEO Rick Leary said that hundreds of additional employees submitted their proof of vaccination over the last week.

“That means we can start putting additional service back on the road over and above what has been scheduled,” she said.

It is unclear how many employees will be placed on unpaid leave as of Sunday, but the President of the Amalgamated Transit Union Local 113, which represents close to 12,000 TTC workers, told CTV News Toronto on Saturday that he knows of just under 2,000 employees who will be impacted.

"It's around 1,200 operators, 500 or 600 maintenance personnel, which varies from a different variety of jobs," Carlos Santos said.

As a result of the vaccine mandate and the worker shortage, a number of temporary changes were made to the TTC's schedule. Officials said the changes are meant to "protect existing service on the TTC's most popular bus corridors at the busiest times of day."

Officials also said the TTC will increase service as more employees get the vaccine

Here are some of the changes commuters should be aware of. Full details can be found on the TTC website.

Weekday daytime service on the Line 2 Bloor-Danforth subway will be reduced from every three to four minutes to every four minutes on weekdays. Evening service will be reduced from every six minutes to seven to eight minutes.

Bus and streetcar changes:

7 Bathurst: Weekday service is being reduced to every 10 minutes.

10 Van Horne: Morning and afternoon peak periods on weekdays will be reduced to every 30 minutes.

28 Bayview South: Weekday service will be reduced to every 30 minutes.

41 Keele: On weekdays, service will operate with articulated buses instead of regular length buses. Service levels will be reduced, although the TTC did not provide further details on the timing.

45 Kipling: Service remains unchanged however the end-of-line trip before 3 p.m. will be adjusted so customers are dropped off in the Atwell Drive loop. This was done due to concern over layover time.

48 Rathburn: Service will be reduced during the morning peak period on weekdays to every 22 to 23 minutes.

49 Bloor West: Service will be reduced in the midday and early evening, from Monday to Friday, to every 30 minutes.

50 Burnhamthorpe: Service will be reduced on weekdays to every 17 to 18 minutes in the peak mornings and every 30 minutes in the evenings. On weekends service will be reduced to every 30 minutes.

61 Avenue Rd North: Service will be reduced during morning and afternoon peak periods on weekdays to every 19 minutes. Midday service will be every 30 minutes.

65/365 Parliament: The buses will reverse their direction of travel through The Esplanade and will operate clockwise on the on-street loop via Berkeley Street, The Esplanade, Princess Street, and Front Street West.

74 Mt. Pleasant: Service will be reduced during the peak periods and in the early evening on weekdays to every 27 minutes. In the afternoon peak period, service will be reduced to every 30 minutes and on weekends service will be every 27 minutes.

78 St Andrews: Service will be reduced during the peak periods on weekdays to every 30 minutes.

85 Sheppard East: Buses will change from regular-length buses to articulated busses on weekends to make up for a suspension of service on the 985 Sheppard East Express.

86 Scarborough (Effective Nov. 27): The shuttle bus will operate every 10 minutes from 5:30 to 10 p.m.

89 Weston: On weekdays, service will be reduced to every eight to nine minutes in the mornings, every 12 to 13 minutes midday and in the afternoon, and every 11 to 12 minutes in the evenings. On Saturday evenings as well as Sundays, service will be every 10 minutes.

97 Yonge: Service will be reduced to every 30 minutes. There are a number of changes to the overlay between Davisville Station and Yonge Boulevard. More details can be found on the TTC website.

111 East Mall: Layover time on the north end of the route at Willowridge Road and Richgrove Drive will be reduced.

122 Graydon Hall: Two additional trips will be added in the afternoon peak period around 3 p.m.

512 St Clair: Service will be reduced on weekdays to every six to seven minutes in the daytime and every eight to nine minutes in the evenings.

941 Keele Express: Midday service will be suspended.

Temporary service reductions are also occurring on 48 other routes, although the TTC's website does not specify how long commuters will have to wait.

Here is a list of express routes that will see service suspended temporarily:

925 Don Mills Express – Saturday all-day, Sunday all-day, holidays

929 Dufferin Express – Saturday all-day, Sunday all-day, holidays

938 Highland Creek Express – All service

939 Finch Express – Saturday all-day, Sunday all-day, holidays

941 Keele Express – Monday-Friday midday

943 Kennedy Express – All service – local service will be restored to pre-express schedules (September 2021)

953 Steeles East Express – Monday-Friday midday and early evening, Saturday all-day, Sunday all-day, holidays

968 Warden Express – All service - local service will be restored to pre-express schedules (September 2021)

985 Sheppard East Express – Saturday all-day, Sunday all-day, holidays

The TTC says that ridership is at about 50 per cent pre-pandemic levels.