Fewer than half of health care workers were willing to accept prepandemic influenza vaccinations to either the H5N1 or the pandemic H1N1 viruses, despite a jump in the World Health Organization alert level, according to a survey study conducted in Hong Kong.
Even when the WHO alert level for H1N1 increased to 5—indicating confirmed human-human spread—only 48% of those surveyed said they intended to take the vaccine. The most common barriers to vaccination were worries about side effects and doubts about effectiveness, lead authors Josette Chor and Dr. Paul Chan wrote in BMJ online (BMJ 2009; doi:10.1136/bmj.b3391
The findings are of great concern, since vaccination of health care workers provides several key benefits during a disease outbreak, wrote Ms. Chor and Dr. Chan of the Chinese University of Hong Kong, and their associates.
Ms. Chor and her coauthors conducted two surveys in 31 Hong Kong hospitals. The first survey, conducted from January to March, asked physicians, nurses, and other health professionals employed at the facilities if they would take a prepandemic H5N1 vaccine. At that time, the WHO alert level for H5N1 was 3, indicating sporadic disease in humans but no evidence of human-human transmission strong enough to generate a community outbreak.
The second survey was conducted in May, after the WHO influenza alert level for H1N1 had been raised to phase 5. This survey asked about the willingness to accept both of the vaccines.
A total of 2,255 health care workers responded to the surveys. Nurses accounted for 71% of the respondents and physicians for 19%.
Overall, only 28% of respondents to the first survey said they would accept an H5N1 vaccine. That percentage increased, though not significantly so, to 35% for the second survey.
More respondents (48%) said they would accept an H1N1 vaccine. Most of those who said they would accept H5N1 vaccination said they would also accept H1N1 vaccination (91%). But only 24% of those who would decline the H5N1 vaccine said they would accept the H1N1 vaccine.
The most common reasons for vaccine acceptance were a wish to be protected and the following of government advice. The most common reasons for declining vaccination were worry about side effects and doubts about vaccine efficacy.
The investigators declared that they had no conflicts.