Skip to main content
. Author manuscript; available in PMC: 2019 Jul 17.
Published in final edited form as: Vaccine. 2017 Apr 9;35(20):2668–2675. doi: 10.1016/j.vaccine.2017.03.082

Table 2.

Adverse event rates in risk and comparison intervals, influenza immunizations between July 1, 2007 and March 31, 2014 for children 2–18 years of age with a history of asthma prior to the immunization, Kaiser Permanente Northern California.

Event Group or subgroup analyzed Interval (days)a Number of events by type of immunization child receivedb Events per 100 K children immunized
IIV LAIV IIV LAIV
Inpatient and ER asthma exacerbation visits All Risk 395 11 119 19
Comparison 389 22 118 39
Current or recent, persistent Risk 343 6 220 43
Comparison 340 9 218 64
Current or recent, not persistent Risk 46 2 50 12
Comparison 44 8 48 50
Remote history of asthma only Risk 6 3 7 11
Comparison 5 5 6 19
Outpatient asthma exacerbation visits, after chart review confirmation All Risk c 242 c 426
Comparison c 349 c 614
Current or recent, persistent Risk c 129 c 919
Comparison c 187 c 1332
Current or recent, not persistent Risk c 83 c 514
Comparison c 112 c 693
Remote history of asthma only Risk 211 30 257 113
Comparison 192 50 234 188
All non-asthma related visits Risk 51,228 8270 15,486 14,553
Comparison 47,633 7643 14,399 13,450
a

The risk interval was 1–14 days after immunization. The Comparison interval was 29–42 days after immunization. All events included here occurred in either the risk or comparison intervals in relation to immunization.

b

IIV: inactivated influenza vaccine; LAIV: live attenuated influenza vaccine.

c

Not available because chart review abstraction and confirmation was only performed for events following LAIV immunizations and for the subset of events following IIV immunization among children with remote history of asthma only.