Thousands of NSW students are being targeted with a further run of meningococcal vaccines.

NSW will vaccinate more students against meningococcal in a bid to immunise the community against a particularly virulent strain of the disease.

More than 200,000 students have been vaccinated against multiple strains of meningococcal since 2017 in a $17 million program.

The state-funded program includes the less common W strain because it has an eight per cent mortality rate - twice as high as other meningococcal strains - and diagnoses are on the rise.

Premier Gladys Berejiklian on Sunday announced a further $3.6 million to roll the ACWY vaccine out to more students in year 10 and 11.

Paddington's Lily O'Connell, speaking alongside the premier, came down with flu like symptoms on Christmas Day.

By that evening she was diagnosed with the W strain and placed in intensive care - where she would remain for eight days.

"If I'd waited any longer I probably wouldn't have made it," she said.

But the disease destroyed her kidneys and she now spends five hours every second day on dialysis.

"Luckily my sister is donating a kidney to me in two weeks time which is very exciting," she said.

The W strain became a concern for the state's health authorities after diagnoses quadrupled between 2014 and 2016.

NSW chief health officer Kerry Chant said adolescents were being targeted by the program because schools are an effective way to immunise high numbers of an at-risk group.

The vaccine is also available for purchase for the wider community and Dr Chant urged people to remain vigilant for symptoms as spring usually brings an increase in meningococcal cases.

"If you experience symptoms including a sudden onset of fever, headache, nausea, vomiting, neck stiffness, joint pain or rash of red-purple spots, go straight to your nearest emergency department to seek help," Dr Chant said.

"Acting quickly can save your life."