Intradermal Trivalent Influenza Vaccine With Imiquimod

Summary

Despite the WHO International Health Regulations Emergency Committee declared an end to the 2009 H1N1 pandemic globally, the emergence of the novel 2009 H1N1 virus in March 2009 has affected more than 214 countries with at least 18000 deaths \[1\]. Patients with chronic underlying illness and extreme of ages are at risk of developing severe disease and complications \[2-3\]. Resistance to oseltamivir has also been reported \[4\]. Therefore, vaccination with the 2010/2011 trivalent influenza vaccine (TIV) with the 2009 H1N1-like virus incorporated will be the best protection against the influenza infection, especially among the at risk population. Recent study on dose sparing seasonal influenza vaccine delivered via a novel intradermal microneedle has demonstrated good immunogenic responses similar to full-dose intramuscular vaccination \[6\]. Poor immunogenicity of the H1N1 2009 component of the trivalent influenza has been reported \[7\].

Study has also suggested the combined intradermal vaccination with local stimulation of dermal antigen presenting cells by applying imiquimod cream (Aldara) to the injection site, which activate antigen presenting cells (APC) through the toll-like receptor 7 (TLR7) may produce better immunogenicity \[8\].

Imiquimod cream is currently registered for the treatment of warts and basal cell carcinoma. Scientific evidence has demonstrated that after treatment with imiquimod, the antigen is processed and presented to cells of the adaptive immune system leading to clearance of the virus and subsequent clearance of the lesions \[9\]. In addition to functional maturation, imiquimod induces migration of dendritic cells from the dermis to draining lymph nodes \[10,11\]. Subcutaneous administration of imiquimod as vaccine adjuvant simultaneously with the antigen of interest, has shown to induce enhanced responses towards the administered antigen \[12\].

We therefore performed a prospective, double blind, randomized controlled study to compare the safety and immunogenicity between intradermal 2011/2012 TIV immunization with pretreatment of imiquimod cream and conventional full dose intramuscular 2011/2012 TIV immunization with pretreatment of aqueous cream as control.

Conditions

• Chronic Illness

Interventions

BIOLOGICAL

influenza vaccine

single dose of intradermal 15 mcg non-adjuvanted 2011/2012 trivalent influenza vaccine

DRUG

Imiquimod

pretreatment with topical imiquimod cream to the injection site before vaccination

BIOLOGICAL

influenza vaccine

single dose of intradermal 15mcg non-adjuvanted 2011/2012 trivalent influenza vaccine

DRUG

Aqueous cream

pretreatment with topical aqueous cream to the injection site before vaccination

BIOLOGICAL

influenza vaccine

single dose of intramuscular 15mcg non-adjuvanted 2011/2012 trivalent influenza vaccine

DRUG

Aqueous cream

pretreatment with topical aqueous cream to the injection site before vaccination

Sponsors & Collaborators

• The University of Hong Kong

  lead OTHER

Principal Investigators

• Ivan FN Hung, MD FRCP · The University of Hong Kong

Study Design

Allocation

RANDOMIZED

Purpose

PREVENTION

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

21 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2012-01-31

Primary Completion

2012-12-31

Completion

2012-12-31

Countries

• Hong Kong

Study Locations