Intradermal Trivalent Influenza Vaccine With Imiquimod
Status:
Completed
Trial end date:
2012-12-01
Target enrollment:
Participant gender:
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.