NSW Health's director of communicable diseases, Vicky Sheppeard said the latest data shows 37 people have died since January from flu-related illnesses and the number of confirmed cases are also up.

"The best weapon against flu is vaccination and right now is the best time to have it as the flu season is already here," Dr Sheppeard said.

"In line with last year's reports, the latest analysis includes Births, Deaths and Marriages and flu notification data, which demonstrates that there were 37 deaths in people with confirmed flu this year, between January and May 19, which reflects the early unseasonal flu numbers we have seen."

Deaths in aged-care outbreaks have increased from nine to 10 this year to date.

The report shows 48 confirmed flu cases in the Murrumbidgee for the week ending May 19 and 1320 across NSW, higher than the 979 notifications in the previous week.

"It's important to get your flu shots now as it takes about two weeks for the vaccine to provide full protection and children under nine years of age having the shot for the first time require two doses, one month apart."

"Children are particularly susceptible to flu so parents and carers are being urged to take up the offer of the free flu vaccine for children aged from six months up to five years under the NSW Government's $2.6 million program."

One Riverina mother, who did not want to be named, said she had made the decision to have herself, her husband and seven-month-old daughter vaccinated against the flu after the family had contracted a cold virus.

"I am very pro-vaccination and I just didn't want anyone getting any sicker," she said.

NSW Health is encouraging parents to organise their children's flu shots as soon as possible.

"There are ample supplies of influenza vaccine and we urge parents of children under five years of age and others vulnerable to influenza to visit their GP," Dr Sheppeard said.