Section 18: substituted, on 7 July 2010, by section 4 of the Epidemic Preparedness Amendment Act 2010 (2010 No 64).
Section 18(2): inserted, on 28 October 2021, by section 3 of the Secondary Legislation Act 2021 (2021 No 7).
Section 18(3): inserted, on 28 October 2021, by section 3 of the Secondary Legislation Act 2021 (2021 No 7).