A randomized control trial comparing immunogenicity, safety, and preference for self- versus nurse-administered intradermal influenza vaccine.
BACKGROUND
Intradermally administered influenza vaccine is as immunogenic as intramuscular vaccine at a lower unit dose. New microinjection systems could allow self-administration of vaccine, potentially reducing the cost and inconvenience.


OBJECTIVE
To compare the immunogenicity, reactogenicity, success rate, and acceptability of self- versus nurse-administered intradermal trivalent seasonal influenza vaccine.


METHODS
Adults (18-59 years old) were randomized to either self- or nurse-administered intradermal vaccine. Prior to vaccination, participants completed a questionnaire and had blood drawn for hemagglutination inhibition titres. Participants in the nurse-administered group were vaccinated by study personnel. The self-administered group were given an instruction sheet and administered their own vaccine. All participants completed a questionnaire and adverse event diaries for 21 days post vaccination, at which time blood was again collected.


RESULTS
Of the 228 participants, 115 were randomized to self-administration and 113 to nurse administration. Groups did not differ by sex, age, or levels of seroprotection at baseline. Of the 114 who completed self-administration, 106 (93%) were successful on the first attempt. There were no group differences in measures of immunogenicity for any of the strains. Self-administering participants reported a lower mean pain rating at vaccination but had larger areas of redness post-vaccination. Seventy percent of all participants said they would prefer intradermal over intramuscular vaccinations in the future, if given the choice.


CONCLUSIONS
Compared to nurse-administered intradermal influenza vaccine, self-administered vaccine was immunologically non-inferior and reached all EMA immunogenicity criteria for the A strains, was highly successful and well-accepted by study participants. Together, these data provide preliminary evidence of feasibility for this method of influenza vaccine administration, which may improve vaccine uptake in adults and increase efficiency of vaccine delivery during outbreaks.
Mount Sinai Hospital, Department of Microbiology, Toronto, Canada. bcoleman@mtsinai.on.ca
Brenda L
BL
Coleman
Allison J
AJ
McGeer
Scott A
SA
Halperin
Joanne M
JM
Langley
Yassein
Y
Shamout
Anna
A
Taddio
Vibhuti
V
Shah
Shelly A
SA
McNeil
D000293:Adolescent; D000328:Adult; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology; D005260:Female; D006385:Hemagglutination Inhibition Tests; D006805:Human Experimentation; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D007271:Injections, Intradermal; D008297:Male; D008875:Middle Aged; D009726:Nurses; D012646:Self Administration; D011795:Surveys and Questionnaires; D014611:Vaccination / Q000379:methods*; D055815:Young Adult
D007252:Influenza Vaccines