A new anti-viral drug should only be used when necessary

Pharmac has secured 60-thousand courses of the pill from Pfizer, which helps prevent serious illness in people with mild Covid symptoms.

It's set to arrive in April and will be rolled out pending Medsafe approval.

But, Auckland University microbiologist Siouxsie Wiles says with drugs like these, the virus can evolve to become resistant to them.

She says it's like antibiotics to treat a bacterial infection, because if those are misused, the bacteria become resistant.