The Health Ministry says there is no need for anyone to worry about the transition to new stocks of a vaccine.
A young woman receives a dose of HPV vaccine Gardasil. Photo: BSIP / AFP
From today, the Gardasil vaccine will be replaced by one covering extra strains of the human papillomavirus, or HPV.
The existing vaccine, Gardasil 4, will be replaced by Gardasil 9, which will be offered to Year 8 boys and girls through their schools.
Gardasil 4 will be funded through GPs for those aged nine to 26 until stocks are used up.
The ministry's director of protection, regulation and assurance, Stewart Jessamine, said both versions were safe and effective.
"For boys and young men the HPV4 provides really almost exactly the same degree of protection as the HPV9.
"For women there is a small difference, but it is a small difference in long-term effect in that most of the common strains of HPV that cause cervical cancer and cancer in women are already covered in the HPV vaccine."
Immunisation Advisory Centre director Nikki Turner advised those who were eligible not to delay getting the vaccine.
"If you choose to delay getting your vaccine on the assumption you want to wait till the general practice has switched over to HPV9, there is naturally a risk in the meantime that your child may be exposed to the HPV virus.
"Our general advice would be both these vaccines are excellent, if and when they're available, we would advise the young person to have them."