A: The rules of sick leave and sick pay still apply with long COVID.
If an employee is unable to work long hours, or perform particular jobs, the company could turn to their capability procedure (in the Staff Handbook) to see if there is a possibility to relieve responsibilities or temporarily switch to part-time hours.
Long COVID that lasts longer than a year could be classed as a disability and will require further reasonable adjustments from the employer.
Further reading
Long Covid - Your Covid Recovery