Chamberlain said it was true that the DHB had been encouraging the ministry to approve a vaccination campaign since May, "being fully aware that we were likely to have to wait until outbreak status was reached".
The Ministry of Health said it convened the Technical Advisory Group in late October over the Northland and nationwide cases because of growing concern over the rising numbers.
The group confirmed on November 8 that the numbers of MenW in Northland met the criteria for a community outbreak for children aged under 10 years because of the region's latest cases in October, said Deputy Director of Public Health Niki Stefanogiannis.
The definition of a community outbreak of meningococcal disease is three or more confirmed cases of the same strain within a three-month period that are not linked and are within a specific age group or community group and the rate of disease is at least 10 cases per 100,000 people.
The Technical Advisory Group then recommended a vaccination programme should be implemented in Northland, Stefanogiannis said.
On Monday the Government announced an urgent immunisation programme to fight the outbreak in Northland, which has had the highest number of cases and deaths of the strain.
Three of the six nationwide MenW deaths this year, including a 7-year-old girl and a teenage boy, occurred in Northland. The number of MenW cases nationwide jumped from five in 2016 to 29 this year, including seven in Northland.
The vaccination programme will start on December 5 and target children aged 9 months to four years, and those aged 13 to 19 years.
National's associate health spokesman Shane Reti has accused Health Minister David Clark's description of the outbreak as a "slight rise" in the disease.
"This is a callous and absolutely appalling description of a fatal disease which has caused devastation in a number of communities," Reti said.
He said the Ministry of Health's own immunisation update described it as an outbreak as early as May.
"That's six months before the official notice was released. This gave the Government significant time to request and begin a response and yet by the Minister's own admission he wasn't even aware of the response till last week," Reti said in a statement.
Clark told reporters today that the Ministry of Health had kept him briefed all year on meningococcal incidents.
"They're happening all the time across New Zealand. Meningococcal disease is not new.
"If there's any hint that a trend might be arising that, appropriately, sparks conversations among clinicians."
Clark said ESR data showed a slight rise in cases over a series of months.
"We are, of course, rightly concerned when we see a strain which is particularly virulent looking like it's starting to gain a toehold."
