Northland businesses are bracing for a "particularly nasty" flu season with some offering free immunisations for workers.
The 2013 national influenza immunisation campaign was launched this week with a goal of immunising 20 per cent more people than last year. In Northland 31,642 vaccinations were administered in 2012.
Influenza (the flu), can be a serious illness and is sometimes fatal. While a person's general health affects the severity of infection, the virus is contagious and anyone can become infected.
Whangarei-based Staff Care provides immunisations to businesses and is bracing for a busy flu season.
Company director Mary Cook said the scheme was beneficial for businesses as they did not lose productivity when flu season struck - which was important as this year's strain was meant to be "particularly nasty".
"It hits the Northern hemisphere first and we're lucky for that to happen because it means that we know what's hanging around. Apparently the flu in America has been pretty bad."
The company conducted more than 900 vaccinations in Northland last year, Ms Cook said.
Health Minister Tony Ryall said the goal this year is to vaccinate 1.2 million people.
"Around 400 New Zealanders die, directly or indirectly, each year from influenza.
"Last year the disease put more than a thousand people in hospital and nearly 50,000 people visited their GP with influenza-like illness."
Last year over more than a million New Zealanders had a flu jab - about 23 per cent of the population.
Although some influenza symptoms are the same as a bad cold, the virus is usually much more severe.
Symptoms include a cough, headache, fever or chills, body aches and pains, fatigue and generally feeling miserable.
Immunisation is free for adults and children with long-term health conditions, pregnant women and people aged 65 and older. The virus can infect up to one-in-five people annually.
It takes about two weeks to develop immunity once vaccinated. Vaccines are available from general practices, accident and medical centres, workplace occupational health service vaccinators and some pharmacies.