One of the first studies on behavioral intentions and A/H1N1 vaccination is just published on bmj.com. It reports that almost half of adults surveyed in summer 2009 in Hong Kong (45 percent) say they would take up free swine flu vaccination. However, this figure drops to around 1 in 7 (15 percent) if the price they have to pay for the vaccine reaches $26 (£16; 17 euros; $HK200). In the absence of proved efficacy and safety, the figure decreases to less than 1 in 20 (5 percent).

Lead author Professor Lau at the Chinese University of Hong Kong and colleagues, conclude that uptake of swine flu vaccination among the general population is not likely to be high. Moreover, it would be sensitive to price and safety of the vaccine.

In addition, the results of the study reveal that more than 6 out of 10 (63 percent) people wrongly trust that the efficacy of the vaccine had been confirmed by clinical trials. Around one in six (16 percent) judge it is indispensable for all Hong Kong people to be vaccinated against swine flu.

In September 2009, there were over 22,000 confirmed swine flu cases in Hong Kong resulting in 15 associated deaths. The Hong Kong government has proposed to purchase 5 million shots of the vaccine. It was announced it would firstly be offered to 2 million high risk groups. The government also estimated that 500,000 people could voluntarily pay for vaccination; however pricing has still not been approved.

After the announcement of A/H1N1 as a pandemic on June 11, Lau and colleagues used a telephone questionnaire to interview a random sample of 301 adults between July 2 to 8. Telephone numbers were randomly selected from current telephone directories. More than 95 percent of households in Hong Kong have a telephone line installed. At least three calls were made before the number was considered invalid. To avoid over-representation of people not working, interviews were done in the evening (from 6.30pm to 10pm).

There was a 80 percent response rate. Respondents were between 18 and 60 years of age. 55 percent were female and 47 percent were below 40 years old.

Participants were questioned about:

• their knowledge of the vaccine
• the seriousness of the pandemic
• their perception of risk

A third (30 percent) mistakenly believed that more than 1 percent of those who contracted swine flu would die. Around one in ten considered that they, their family or the general population had a high or very high chance of contracting the disease.

In closing, Professor Lau says that from the results “it seems that free or low cost vaccination needs to be provided to achieve a high rate of vaccination against A/H1N1. More importantly, the general public has to be convinced about the vaccine’s efficacy and safety as misconceptions may exist about what the scientific data show.”

“Acceptability of A/H1N1 vaccination during pandemic phase of influenza A/H1N1 in Hong Kong: population based cross sectional survey”
Joseph T F Lau, associate director and professor, Nelson C Y Yeung, research assistant, K C Choi, research associate, Mabel Y M Cheng, junior research assistant, H Y Tsui, research associate, Sian Griffiths, director and professor
BMJ 2009; 339:b4164
doi:10.1136/bmj.b4164
bmj.com

Written by Stephanie Brunner (B.A.)