Dr Caroline McElnay, director of Public Health at the Ministry of Health, said the vast majority of influenza vaccinations this year had already taken place, but the extra amount should ensure they were available for high-risk people who had not yet been immunised.
Those at the greatest risk include pregnant women, children under 4 with serious respiratory illnesses, those over 65, people with severe asthma, heart disease, diabetes and other serious health conditions that make them susceptible to flu.
Dr McElnay said those ineligible for free influenza vaccination would have to pay the usual price which varied between providers, but was between $30 and $40.
The flu virus, which took hold late this season, is expected to peak late this month and into August.
Institute of Environmental Science and Research (ESR) figures show 47 per cent, or 23 out of 48 patients, tested by their GPs in Northland between April 21 and June 9 returned a positive result for influenza. Only Canterbury and Waitemata DHBs have higher flu rates than Northland.
The additional 55,000 doses will take the total number of influenza vaccines to 1.38 million, the highest number ever made available in New Zealand in a single winter.
Washing hands, safe sneezing, and staying home if is unwell are other ways to reduce the spread of winter illnesses, including flu.