WASHINGTON — Adult and childhood influenza
immunization rates remain low, and a new study presented during the 45th Annual
National Immunization Conference suggests that it may be because many do not
understand their risk status.
Annual influenza vaccination is recommended for anyone
who is at increased risk or lives with anyone who is at increased risk for
Aurimar Ayala, MPH, epidemiologist, Maricopa
County Department of Public Health, and Steven Baty, DVM, MPH, a CDC
epidemic intelligence service officer with the Arizona Department of Health
Services, presented data this week indicating that many people do not
understand that their medical conditions or their children’s medical
conditions put them at high risk for influenza complications and should
therefore be vaccinated.
According to the study abstract, the researchers’
objective was to determine factors associated with receipt of 2009 influenza A
(H1N1) monovalent and seasonal influenza immunization among Maricopa County
adult respondents living with school-aged children. They found that the
association of adult influenza vaccination was stronger for adults living in a
household with any adult with a high-risk condition compared with living with a
child with a high-risk condition.
According to Ayala, they identified 600 households
through random-digit dialing who met the criteria for enrollment. The primary
outcome was both H1N1 and seasonal immunization. In 186 (31%) households, at
least one adult received H1N1 vaccination. Of these households, 54 (29%) and 73
(39%) had a child or adult with a high-risk condition, respectively. In 257
(43%) households, at least one adult received seasonal influenza immunization.
Of these households, 73 (28%) and 95 (37%) had a child or adult with a
high-risk condition, respectively.
“We found that 51% of school-age children with a
high-risk medical condition were not recognized by their parents for being
at-risk for influenza complications,” Baty said during his presentation.
“Fifty-seven percent of household didn’t realize they had an adult
with a high-risk condition that complicates influenza.”
According to the study results, after adjusting for
race/ethnicity and health insurance in two separate models, factors
independently associated with adult H1N1 or seasonal influenza vaccination
included a high-risk medical condition in a child (H1N1 vaccination adjusted OR
[HAOR]=1.8; 95% CI, 1.1-2.8); a seasonal influenza vaccination adjusted OR
(SAOR) of 1.6 (95% CI, 1-2.6); a high-risk medical condition in any adult
(HAOR=2.3; 95% CI: 1.4–3.7; SAOR: 2.7; 95% CI: 1.7–4.5); and college
degree attainment (vs. nonattainment) of respondent (HAOR=2.1; 95% CI, 1.4-3.1;
SAOR=1.9; 95% CI, 1.3-2.7).
The researchers concluded that additional studies are
needed to better understand these differences.
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