An increase in immunisations is promising for the whooping cough epidemic

Doses of Boostrix administered among 15-44-year-olds, have doubled from about 1000 per week to over 2000.

The vaccine builds immunity against the respiratory infection as well as diphtheria and tetanus.

National Public Health Service Medicine Specialist Dr Matt Reid says it's an encouraging sign more Kiwis are responding to their call to action

He says it's happened after they declared the epidemic and promoted vaccination - so it's promising.