With news that two cases of monkeypox have been detected in Australia, the chances that the disease might arrive in New Zealand continue to grow, says The Spinoff. It is a respiratory virus and can spread to humans without contact, probably through aerosols. Research shows waning of immunity from smallpox vaccination may explain the increasing outbreaks of monkeypox – it is more than 40-50 years since mass vaccination ceased in other countries (New Zealand never had a mass smallpox vaccination programme).