The study was part of a rapid response initiative; therefore focus groups were selected as the most efficient means of data collection in the time available. Eight semi-structured focus groups were recruited between May and July 2010 (the New Zealand winter season) comprising 7 to 13 participants each and lasting approximately 1 hour. Separate focus groups were conducted for each of the target groups with a total of 80 participants representative of five target populations groups identified in consultation with Ministry of Health staff: Māori, Pacific Peoples, children (or parents of children), general population, and vulnerable people with chronic conditions (defined as those who are eligible for subsidised vaccinations, such as pregnant women, those with diabetes, using asthma inhalers, with heart disease or kidney problems. Participant characteristics are summarised in Table 1 .