Simon Bridges has lashed out at the Government over its handling of the measles outbreak.
The total number of measles cases in New Zealand has now reached 1576, with alone 1307 in Auckland.
On Tuesday, Auckland health officials confirmed five pregnant people had caught measles during the latest outbreak, with two of the fetuses dying.
It is not known if the babies died directly from measles, with one death associated with other complications. The deaths were classified as the result of "serious complications potentially related to maternal measles".
Bridges said he believes the Government could have been more involved in managing the outbreak, which was worst in Auckland.
"[Health Minister David Clark] should be out there leading this, instead it's faceless bureaucrats we're seeing on this measles epidemic."
Clark is Health Minister, but responsibility for responding to the outbreak fell to Associate Minister of Health Julie Anne Genter, who is in charge of public health including immunisation.
Genter rolled out extra vaccinations for the Auckland region, particularly in South Auckland, which was hardest hit by the outbreak.
David Clark refused to comment as the outbreak is not the minister's area of responsibility.
Genter said DHBs have targets for immunisation and there has been huge uptake over the past year.
"We have seen record amounts of people getting vaccinated, but our health system has been run down over so many years by the previous National Government that we don't have a strong system in place to start with. Our government is strengthening our health system.
"Approximately 180,000 people have been vaccinated this year, compared to 95,000 last year. More vaccine is coming, with 100,000 coming in the next few weeks and a further 70,000 before the end of the year."