Many employers don’t pay staff for time taken off sick, or it is only for a limited time. Check your staff handbook or employment contract, if you have one, to see what it says. You may be entitled to Statutory Sick Pay (SSP), though. On 12th March, the government confirmed emergency plans to allow people to claim SSP from day one of any absence related to Coronavirus. (It is still paid through your employer.)
Before this outbreak, SSP was available to paid employees but only from the fourth day of absence from work due to illness. The rate for SSP is currently £95.85 per week. More info on statutory sick pay is available here: https://www.gov.uk/statutory-sick-pay/how-to-claim