BOSTON — Mayor Marty Walsh said Wednesday the city’s antibody testing initiative is underway and expected to be completed by the end of the week.

The initiative, announced Sunday, will test 1,000 Boston residents randomly selected from East Boston, Roslindale, and within the boundaries of zip codes 02121 and 02125 in Dorchester. The residents will also be tested for the coronavirus.

The results will help give an understanding of the prevalence of the coronavirus in Boston. The city has seen 8,316 confirmed cases of COVID-19 and 333 deaths related to the virus, Walsh said Wednesday. The number of unconfirmed cases is thought to be much higher as many people with the coronavirus are asymptomatic.

Ahead of the first of the month, Walsh also reminded Boston residents that residents and homeowners are legally protected from losing their homes during this time. Anyone having trouble making rent or mortgage should contact their bank.

Baker also reminded people who are exercising outside to wear masks, even though Boston still hasn’t made it mandatory.