Randomized Controlled Trial to Compare Immunogenicity of Standard-Dose Intramuscular Versus Intradermal Trivalent Inactivated Influenza Vaccine in HIV-Infected Men Who Have Sex With Men in Bangkok, Thailand.
BACKGROUND
Individuals infected with human immunodeficiency virus (HIV) are at increased risk for severe influenza, yet immune responses to standard-dose intramuscular (IM) influenza vaccine are suboptimal in this population. Intradermal (ID) delivery of influenza vaccine might improve immune response through enhanced stimulation of dendritic cells.


METHODS
We conducted a randomized, double-blind, controlled trial to compare the immunogenicity of off-label standard-dose (15 µg) ID vs standard-dose (15 µg) IM inactive influenza vaccine in HIV-infected men in Bangkok, Thailand. The primary study outcome was seroconversion (minimum titer of 1:40 and ≥4-fold rise in antibody titer) at 1 month postvaccination based on serum hemagglutination inhibition antibody titers against each vaccine strain. Adverse events (AEs) in the 7 days following vaccination were also assessed.


RESULTS
We enrolled 400 HIV-infected participants; 200 were randomly assigned to receive IM and 200 ID vaccine. Vaccine arms were well-balanced with respect to age, CD4 cell count, HIV RNA load, and antiretroviral treatment. Percentage of seroconversion to all (ID 14% vs IM 15%; P = .8) or at least 1 (ID 69% vs IM 68%; P = .7) of the 3 vaccine strains did not differ significantly between ID vs IM vaccine recipients. A higher proportion of participants who received ID vaccine had mild injection-site AEs compared with participants who received IM vaccine (77% vs 27%).


CONCLUSIONS
There were no significant differences in the immunogenicity of standard-dose ID vs IM influenza vaccine in this HIV-infected population in Thailand. Additional strategies to enhance immune responses to influenza vaccine among HIV-infected persons are needed.


BACKGROUND
NCT01538940.
Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention.|Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia.
Shikha
S
Garg
SirirajHospital, Bangkok, Thailand.
Prasert
P
Thongcharoen
Thailand Ministry of Public Health-US CDC Collaboration, Centers for Disease Control and Prevention.
Prabda
P
Praphasiri
Department of Disease Control, Ministry of Public Health, Nonthaburi.
Anupong
A
Chitwarakorn
SirirajHospital, Bangkok, Thailand.
Pornchai
P
Sathirapanya
Armed Forces Research Institute of Medical Sciences.
Stefan
S
Fernandez
Armed Forces Research Institute of Medical Sciences.
Kamonthip
K
Rungrojcharoenkit
Thailand Ministry of Public Health-US CDC Collaboration, Centers for Disease Control and Prevention.
Wannee
W
Chonwattana
Thailand Ministry of Public Health-US CDC Collaboration, Centers for Disease Control and Prevention.
Philip A
PA
Mock
Thailand Ministry of Public Health-US CDC Collaboration, Centers for Disease Control and Prevention.
Wichuda
W
Sukwicha
Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia.
Jacqueline M
JM
Katz
Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia.
Marc-Alain
MA
Widdowson
Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention.|Thailand Ministry of Public Health-US CDC Collaboration, Centers for Disease Control and Prevention.
Marcel E
ME
Curlin
Armed Forces Research Institute of Medical Sciences.
Robert V
RV
Gibbons
Division of HIV/AIDS Prevention, National Center for HIV/AIDS, Viral Hepatitis, STD and TB Prevention.|Thailand Ministry of Public Health-US CDC Collaboration, Centers for Disease Control and Prevention.
Timothy H
TH
Holtz
Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia.
Fatimah S
FS
Dawood
Influenza Division, Centers for Disease Control and Prevention, Atlanta, Georgia.|Thailand Ministry of Public Health-US CDC Collaboration, Centers for Disease Control and Prevention.
Sonja J
SJ
Olsen
D000293:Adolescent; D000328:Adult; D000914:Antibodies, Viral / Q000097:blood; D004311:Double-Blind Method; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D015658:HIV Infections / Q000150:complications*; D006385:Hemagglutination Inhibition Tests; D018451:Homosexuality, Male; D006801:Humans; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology; D007251:Influenza, Human / Q000517:prevention & control*; D007271:Injections, Intradermal / Q000009:adverse effects; D007273:Injections, Intramuscular / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D013785:Thailand; D016896:Treatment Outcome; D015164:Vaccines, Inactivated / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology; D055815:Young Adult
D000914:Antibodies, Viral; D007252:Influenza Vaccines; D015164:Vaccines, Inactivated
HIV; immunogenicity; influenza; intradermal; vaccine