Those at greater risk from flu include people with health conditions such as severe asthma, chest or heart complaints and diabetes, pregnant women and people aged over 65 and are eligible for a free flu jab.
In London, children in years one and two in primary schools are also being offered the free flu nasal spray vaccination this year at school between October and December.
NHS Sutton Clinical Commissioning Group is supporting this year's Stay Well This Winter campaign, led by NHS England and Public Health England, and is encouraging everyone eligible to get vaccinated.
Some community pharmacists in Sutton are also able to provide the free flu jab (but not the nasal spray) to at risk groups.
Dr Chris Elliott, a local GP and Chief Clinical Officer of NHS Sutton Clinical Commissioning Group, said flu can be dangerous for young children.
"If you have children aged two, three or four, or in school years one and two, don't put off taking up their free flu vaccination," he said. "The nasal spray vaccination is a quick, painless and effective way for children to be protected without the need for injections.
"Flu can be a very unpleasant illness in children as they suffer the same symptoms as adults including fever, chills and aching muscles and the flu vaccination will help protect your child from flu and also reduce the chance of flu spreading to others.
"Anyone over the age of 65 or with an existing health problem should also make sure they get the flu jab as flu can make the effects of existing conditions worse and make complications like pneumonia more likely."
For more information about the nasal spray vaccination and the flu jab visit http://www.nhs.uk/staywell/