An immunisation researcher says cost is the major barrier to vaccinating boys against a virus that causes cervical cancer.
The Ministry of Health is asking the Government's drug-buying agency Pharmac to consider giving teenage boys the vaccine Gardasil, which girls already receive.
Gardasil protects against the human papilloma virus, which can cause cervical cancer, genital warts, and some male cancers.
Australia has just started funding it for boys.
Immunisation Advisory Centre director Nikki Turner says Gardasil is an effective vaccine, but giving it to boys would be expensive and there may be more cost-effective ways of spending that money.
Pharmac says it will make its decision later this year.