The victims were approached by a group in Hitchin, Hertfordshire, and it was reported that one of them coughed in the face of the couple.
BBC reports there was an ‘altercation’ after a passer-by intervened and that a woman in her 70s was left with a black eye.
Two men, 18 and 19, and a boy, aged 16, were arrested on suspicion of actual bodily harm, affray and criminal damage following the incident on Friday afternoon.
The elderly woman was taken to hospital for a check-up and was later discharged, Hertfordshire Police said.
While the passer-by who intervened suffered bruising.
The force has asked for anyone with to contact them.
Coronavirus: the facts
What is coronavirus?
Covid-19 is a respiratory illness that can affect lungs and airways. It is caused by a virus called coronavirus.
What caused coronavirus?
The outbreak started in Wuhan in China in December 2019 and it is thought that the virus, like others of its kind, has come from animals.
How is it spread?
As this is such a new illness, experts still aren’t sure how it is spread. But similar viruses are spread in cough droplets. Therefore covering your nose and mouth when sneezing and coughing, and disposing of used tissues straight away is advised. Viruses like coronavirus cannot live outside the body for very long.
What are the symptoms?
The NHS states that the symptoms are: a dry cough, high temperature and shortness of breath - but these symptoms do not necessarily mean you have the illness. Look out for flu-like symptoms, such as aches and pains, nasal congestion, runny nose and a sore throat. It’s important to remember that some people may become infected but won’t develop any symptoms or feel unwell.
What precautions can be taken?
Washing your hands with soap and water thoroughly. The NHS also advises to cover your mouth and nose with a tissue or your sleeve (not your hands) when you cough or sneeze; put used tissues in the bin immediately and try to avoid close contact with people who are unwell. Also avoiding touching eyes, nose and mouth unless your hands are clean.
Sources: World Health Organisation and NHS