TY  - JOUR
T1  - INdividual and community risks of measles and pertussis associated with personal exemptions to immunization
AU  - Feikin DR, Lezotte DC, Hamman RF, Salmon DA, Chen RT, Hoffman RE
Y1  - 2000/12/27
N1  - 10.1001/jama.284.24.3145
JO  - JAMA
SP  - 3145
EP  - 3150
VL  - 284
IS  - 24
N2  - Context 
                  The risk of vaccine-preventable diseases among children who have philosophical
and religious exemptions from immunization has been understudied.Objectives 
                  To evaluate whether personal exemption from immunization is associated
with risk of measles and pertussis at individual and community levels.Design, Setting, and Participants 
                  Population-based, retrospective cohort study using data collected on
standardized forms regarding all reported measles and pertussis cases among
children aged 3 to 18 years in Colorado during 1987-1998.Main Outcome Measures 
                  Relative risk of measles and pertussis among exemptors and vaccinated
children; association between incidence rates among vaccinated children and
frequency of exemptors in Colorado counties; association between school outbreaks
and frequency of exemptors in schools; and risk associated with exposure to
an exemptor in measles outbreaks.Results 
                  Exemptors were 22.2 times (95% confidence interval [CI], 15.9-31.1)
more likely to acquire measles and 5.9 times (95% CI, 4.2-8.2) more likely
to acquire pertussis than vaccinated children. After adjusting for confounders,
the frequency of exemptors in a county was associated with the incidence rate
of measles (relative risk [RR], 1.6; 95% CI, 1.0-2.4) and pertussis (RR, 1.9;
95% CI, 1.7-2.1) in vaccinated children. Schools with pertussis outbreaks
had more exemptors (mean, 4.3% of students) than schools without outbreaks
(1.5% of students; P = .001). At least 11% of vaccinated
children in measles outbreaks acquired infection through contact with an exemptor.Conclusions 
                  The risk of measles and pertussis is elevated in personal exemptors.
Public health personnel should recognize the potential effect of exemptors
in outbreaks in their communities, and parents should be made aware of the
risks involved in not vaccinating their children.
SN  - 0098-7484
M3  - doi: 10.1001/jama.284.24.3145
UR  - http://dx.doi.org/10.1001/jama.284.24.3145
ER  -