Acceptability of A/H1N1 vaccination during pandemic phase of influenza A/H1N1 in Hong Kong: population based cross sectional survey
Almost half of adults surveyed in Summer 2009 in Hong Kong (45%) say they would take up free swine flu vaccination. However, this figure drops to around 1 in 7 (15%) if the price they have to pay for the vaccine reaches $HK200 (£16; Euro 17; $26). In the absence of proved efficacy and safety, the figure decreases to less than 1 in 20 (5%), according to one of the first studies on behavioural intentions and A/H1N1 vaccination, published on bmj.com today.
The authors, led by Professor Lau at the Chinese University of Hong Kong, conclude that uptake of swine flu vaccination among the general population is unlikely to be high and would be sensitive to price and safety of the vaccine.
The results of the study also reveal that more than 6 out of 10 (63%) people mistakenly believe that the efficacy of the vaccine had been confirmed by clinical trials and around one in six (16%) believe it is necessary 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 and said it would initially 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 agreed.
Lau and colleagues used a telephone questionnaire to interview a random sample of 301 adults between 2-8 July, after the announcement of A/H1N1 as a pandemic on 11 June. Telephone numbers were randomly selected from current telephone directories (over 95% of households in Hong Kong have a telephone line installed), and at least three calls were made before the number was considered invalid. Interviews were done in the evening (from 6.30pm to 10pm) to avoid over-representation of people not working.
The response rate was 80%. Respondents were between 18 and 60 years of age, 55% were female and 47% were below 40 years old.
Participants were also asked about their knowledge of the vaccine, the seriousness of the pandemic and their perception of risk. A third (30%) mistakenly believed that more than 1% of those who contracted swine flu would die and 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 conclusion, 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."