Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza

[tetano]

PLoS One. 2011;6(11):e27953. Epub 2011 Nov 30.
Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza.
Shim BS, Choi YK, Yun CH, Lee EG, Jeon YS, Park SM, Cheon IS, Joo DH, Cho CH, Song MS, Seo SU, Byun YH, Park HJ, Poo H, Seong BL, Kim JO, Nguyen HH, Stadler K, Kim DW, Hong KJ, Czerkinsky C, Song MK.
Source

Laboratory Science Division, International Vaccine Institute, Seoul, Republic of Korea.
Abstract
BACKGROUND:

The ectodomain of matrix protein 2 (M2e) of influenza A virus is a rationale target antigen candidate for the development of a universal vaccine against influenza as M2e undergoes little sequence variation amongst human influenza A strains. Vaccine-induced M2e-specific antibodies (Abs) have been shown to display significant cross-protective activity in animal models. M2e-based vaccine constructs have been shown to be more protective when administered by the intranasal (i.n.) route than after parenteral injection. However, i.n. administration of vaccines poses rare but serious safety issues associated with retrograde passage of inhaled antigens and adjuvants through the olfactory epithelium. In this study, we examined whether the sublingual (s.l.) route could serve as a safe and effective alternative mucosal delivery route for administering a prototype M2e-based vaccine. The mechanism whereby s.l. immunization with M2e vaccine candidate induces broad protection against infection with different influenza virus subtypes was explored.
METHODS AND RESULTS:

A recombinant M2 protein with three tandem copies of the M2e (3M2eC) was expressed in Escherichia coli. Parenteral immunizations of mice with 3M2eC induced high levels of M2e-specific serum Abs but failed to provide complete protection against lethal challenge with influenza virus. In contrast, s.l. immunization with 3M2eC was superior for inducing protection in mice. In the latter animals, protection was associated with specific Ab responses in the lungs.
CONCLUSIONS:

The results demonstrate that s.l. immunization with 3M2eC vaccine induced airway mucosal immune responses along with broad cross-protective immunity to influenza. These findings may contribute to the understanding of the M2-based vaccine approach to control epidemic and pandemic influenza infections.

PMID:
22140491
[PubMed - in process]

http://www.ncbi.nlm.nih.gov/pubmed/22140491

 

[tetano]

Re: Sublingual Immunization with M2-Based Vaccine Induces Broad Protective Immunity against Influenza

Needle-free Universal Vaccine Against Flu Viruses Shows Promise

Scientists from the International Vaccine Institute (IVI) have discovered that an antigen common to most influenza viruses, and commonly referred to as matrix protein 2 (M2), when administered under the tongue could protect mice against experimental infection caused by various influenza viruses, including the highly pathogenic avian H5 virus and the pandemic H1N1 virus.

Importantly, this experimental sublingual vaccine was found to induce immunity in the lungs whereas the same vaccine administered by injection failed to do so and conferred only limited protection against experimental infection. The study, spearheaded by IVI scientist Dr. Man-ki Song and Dr. Haryoung Poo from the Korea Research Institute of Bioscience and Biotechnology (KRIBB), was reported in the Nov. 30, 2011 issue of the journal PLoS ONE.

Current seasonal influenza vaccines are designed to induce immunity against hemagglutinin (HA), a major component of influenza virus. Because HA undergoes frequent mutations, these vaccines have to be reformulated and manufactured every year to incorporate newly emerging influenza virus strains selected by the World Health Organization.

Due to the recent emergence of highly pathogenic influenza virus strains and the threat of a human flu pandemic, health authorities and vaccine producers are under increasing pressure to manufacture and deliver a sufficient number of vaccine doses in a short time, amid a limited global production capacity.

..

http://www.infectioncontroltoday.co...accine-against-flu-viruses-shows-promise.aspx