Elementary School-Based Influenza Vaccination: Evaluating Impact on Respiratory Illness Absenteeism and Laboratory-Confirmed Influenza

Abstract

BackgroundStudies of influenza vaccine effectiveness in schools have assessed all-cause absenteeism rather than laboratory-confirmed influenza. We conducted an observational pilot study to identify absences due to respiratory illness and laboratory-confirmed influenza in schools with and without school-based vaccination.MethodsA local public health agency initiated school-based influenza vaccination in two Wisconsin elementary schools during October 2010 (exposed schools); two nearby schools served as a comparison group (non-exposed schools). Absences due to fever or cough illness were monitored for 12 weeks. During the 4 weeks of peak influenza activity, parents of absent children with fever/cough illness were contacted and offered influenza testing.ResultsParental consent for sharing absenteeism data was obtained for 937 (57%) of 1,640 students. Fifty-two percent and 28%, respectively, of all students in exposed and non-exposed schools were vaccinated. Absences due to fever or cough illness were significantly lower in the exposed schools during seven of 12 surveillance weeks. Twenty-seven percent of students at exposed schools and 39% at unexposed schools had one or more days of absence due to fever/cough illness (p<0.0001). There was no significant difference in the proportion of students absent for other reasons (p = 0.23). During the 4 week period of influenza testing, respiratory samples were obtained for 68 (42%) of 163 episodes of absence due to fever or cough illness. Influenza was detected in 6 students; 3 attended exposed schools.ConclusionsDetection of laboratory-confirmed influenza in schools was challenging due to multiple consent requirements, difficulty obtaining samples from absent children, and a mild influenza season. School-based influenza vaccination was associated with reduced absenteeism due to fever or cough illness, but not absenteeism for other reasons. Although nonspecific, absence due to fever or cough illness may be a useful surrogate endpoint in school-based studies if identification of laboratory confirmed influenza is not feasible.

School absenteeism among school‐aged children with medically attended acute viral respiratory illness during three influenza seasons, 2012‐2013 through 2014‐2015

“…4,26 School absenteeism rates were also lower in schools/ communities with school-based vaccination programs. 5,[27][28][29][30] These studies did not assess the reason for absenteeism or were limited to influenza-like illness. It is possible that vaccination may have resulted in milder illness, leading to fewer outpatient visits.…”

“…There were no differences in prolonged absence by age group, sex, reported health status prior to illness, influenza vaccination status, or receipt of antivirals. 19 (25) 28 (33) 3 (8) 4 (14) 14 (19) 9 (20) 67 (24) 2013-2014 41 (100) 12 (7) 0 0 16 (21) 23 (27) 26 (68) 3 (11) 26 (36) 16 (36) 100 ( 13 (7) 18 (19) 17 (21) 0 3 (4) 0 2 (7) 2 (3) 2 (4) 22 (8) Peak influenza weeks 28 (68) 65 (36) 26 (28) 51 (62) 11 (14) 23 (27) 1 (3) 10 (36) 13 (18) 4 (9) 63 (22) Post-peak influenza weeks (28) 28 (34) 22 (29) 22 (26) 13 (34) 9 (32) 23 (32) 14 (30) 53 (19) Median duration of illness, days (IQR) 6 (5, 9) 6 (4.5, 9) 7 (6,9) 7 (6,9) 7 (5,9) 5 (4, 8) 6 (5, 8)…”

Technical guidelines for the application of seasonal influenza vaccine in China (2014–2015)

“…162 A comparative study of 2 primary schools (coverage rate: 52%) and 2 neighboring schools (coverage rate: 28%, controlled group) showed that when absenteeism 1 day due to fever or cough was set as an indicator, school with high vaccination rates had a significantly lower absenteeism rate (26.5%) than that of controlled (38.9%). 163 The elderly The elderly experience a declining immunogenicity induced by vaccination, which might be attributed to the immunosenescence. 164 A review of 31 studies on HAI antibody response among population aged might antly lower absenteshowed that during influenzawith seroconversion rates of 60%, 62%, and 58% of A(H1N1), A(H3N2), and B-type among young adults, the seroconversion rates in elderly was only 42%, 51%, and 35%.…”

Association of School‐Based Influenza Vaccination Clinics and School Absenteeism—Arkansas, 2012‐2013

“…The onset of influenza season is associated with increases in student absenteeism due to illness, missed work by parent caregivers, and illness among family members or other close contacts . Several studies have demonstrated that influenza vaccination is associated with reduced student absenteeism during influenza season . Student absenteeism has been demonstrated to be lower during influenza season in schools or communities with SBCs than those without SBCs .…”

“…Several studies have demonstrated that influenza vaccination is associated with reduced student absenteeism during influenza season . Student absenteeism has been demonstrated to be lower during influenza season in schools or communities with SBCs than those without SBCs . In addition, studies have demonstrated that absenteeism was decreased in schools with a SBC among vaccinated students versus unvaccinated students .…”