From tomorrow a second Covid-19 booster will be available for older Kiwis, and some other groups

Over 50s, health, aged care and disability workers over 30, and those who are severely immunocompromised are eligible six months after their first booster.

Covid-19 Response Minister Ayesha Verrall says the eligibility criteria could be re-examined in the future.

She says they will be keeping an eye on research about the fourth dose overseas.