Noninvasive vaccination as a casus belli to redeem vaccine value in the face of anti-vaccine movements

Formidable anti-vaccine movements have been growing as a menace to disrupt beneficial vaccine programs. Although the vaccination-associated adverse effects commonly perceived by vaccine resisters usually represent over-reactions to rare manifestations, converging evidence shows that vaccination-associated health threats could be pervasive when systemic inflammation is considered as a side effect that oozes over time. An anti-vaccine movement thus may not be so unfounded even though the myriad cascades triggered by systemic inflammation have not been brought to a clear focus during any anti-vaccine campaign. Since both pro- and anti-vaccine groups are acting on the same primal impulse - "keep people healthy," reconciliation between the two warring factions should be achievable on a palatable trend that fosters the development of noninvasive vaccines which tend to induce local and transient inflammation along the interface with diminished potential to percolate through internal organs.

Avian influenza in ovo vaccination with replication defective recombinant adenovirus in chickens: vaccine potency, antibody persistence, and maternal antibody transfer

Protective immunity against avian influenza (AI) can be elicited in chickens in a single-dose regimen by in ovo vaccination with a replication-competent adenovirus (RCA)-free human adenovirus serotype 5 (Ad)-vector encoding the AI virus (AIV) hemagglutinin (HA). We evaluated vaccine potency, antibody persistence, transfer of maternal antibodies (MtAb), and interference between MtAb and active in ovo or mucosal immunization with RCA-free recombinant Ad expressing a codon-optimized AIV H5 HA gene from A/turkey/WI/68 (AdTW68.H5(ck)). Vaccine coverage and intrapotency test repeatability were based on anti-H5 hemagglutination inhibition (HI) antibody levels detected in in ovo vaccinated chickens. Even though egg inoculation of each replicate was performed by individuals with varying expertise and with different vaccine batches, the average vaccine coverage of three replicates was 85%. The intrapotency test repeatability, which considers both positive as well as negative values, varied between 0.69 and 0.71, indicating effective vaccination. Highly pathogenic (HP) AIV challenge of chicken groups vaccinated with increasing vaccine doses showed 90% protection in chickens receiving > or = 10(8) ifu (infectious units)/bird. The protective dose 50% (PD50) was determined to be 10(6.5) ifu. Even vaccinated chickens that did not develop detectable antibody levels were effectively protected against HP AIV challenge. This result is consistent with previous findings ofAd-vector eliciting T lymphocyte responses. Higher vaccine doses significantly reduced viral shedding as determined by AIV RNA concentration in oropharyngeal swabs. Assessment of antibody persistence showed that antibody levels of in ovo immunized chickens continued to increase until 12 wk and started to decline after 18 wk of age. Intramuscular (IM) booster vaccination with the same vaccine at 16 wk of age significantly increased the antibody responses in breeder hens, and these responses were maintained at high levels throughout the experimental period (34 wk of age). AdTW68.H5(ch)-immunized breeder hens effectively transferred MtAb to progeny chickens. The level of MtAb in the progenies was consistent with the levels detected in the breeders, i.e., intramuscularly boosted breeders transferred higher concentrations of antibodies to the offspring. Maternal antibodies declined with time in the progenies and achieved marginal levels by 34 days of age. Chickens with high maternal antibody levels that were vaccinated either in ovo or via mucosal routes (ocular or spray) did not seroconvert. In contrast, chickens without MtAb successfully developed specific antibody levels after either in ovo or mucosal vaccination. These results indicate that high levels of MtAb interfered with active Ad-vectored vaccination.

Avian influenza vaccination in chickens and pigs with replication-competent adenovirus-free human recombinant adenovirus 5

Protective immunity to avian influenza (AI) virus can be elicited in chickens by in ovo or intramuscular vaccination with replication-competent adenovirus (RCA)-free human recombinant adenovirus serotype 5 (Ad5) encoding AI virus H5 (AdTW68.H5) or H7 (AdCN94.H7) hemagglutinins. We evaluated bivalent in ovo vaccination with AdTW68.H5 and AdCN94.H7 and determined that vaccinated chickens developed robust hemagglutination inhibition (HI) antibody levels to both H5 and H7 AI strains. Additionally, we evaluated immune responses of 1-day-old chickens vaccinated via spray with AdCN94.H7. These birds showed increased immunoglobulin A responses in lachrymal fluids and increased interleukin-6 expression in Harderian gland-derived lymphocytes. However, specific HI antibodies were not detected in the sera of these birds. Because pigs might play a role as a "mixing vessel" for the generation of pandemic influenza viruses we explored the use of RCA-free adenovirus technology to immunize pigs against AI virus. Weanling piglets vaccinated intramuscularly with a single dose of RCA-free AdTW68.H5 developed strong systemic antibody responses 3 wk postvaccination. Intranasal application of AdTW68.H5 in piglets resulted in reduced vaccine coverage, i.e., 33% of pigs (2/6) developed an antibody response, but serum antibody levels in those successfully immunized animals were similar to intramuscularly vaccinated animals.

Topical application of Escherichia coli-vectored vaccine as a simple method for eliciting protective immunity

We report here that animals can be protected against lethal infection by Clostridium tetani cells and Bacillus anthracis spores following topical application of intact particles of live or gamma-irradiated Escherichia coli vectors overproducing tetanus and anthrax antigens, respectively. Cutaneous gammadeltaT cells were rapidly recruited to the administration site. Live E. coli cells were not found in nonskin tissues after topical application, although fragments of E. coli DNA were disseminated transiently. Evidence suggested that intact E. coli particles in the outer layer of skin may be disrupted by a gammadeltaT-cell-mediated innate defense mechanism, followed by the presentation of E. coli ligand-adjuvanted intravector antigens to the immune system and rapid degradation of E. coli components. The nonreplicating E. coli vector overproducing an exogenous immunogen may foster the development of a new generation of vaccines that can be manufactured rapidly and administered noninvasively in a wide variety of disease settings.

Prospective highlights of functional skin proteomics

Although a wide variety of protein profiles have been extensively constructed via proteomic analysis, the comprehensive proteomic profiling of the skin, which is considered to be the largest organ of the human body, is still far from complete. Our efforts to establish the functional skin proteome, a protein database describing the protein networks that underlie biological processes, has set in motion the identification and characterization of proteins expressed in the epidermis and dermis of the BALB/c mice. In this review, we will highlight various cutaneous proteins we have characterized and discuss their biological functions associated with skin distress, immunity, and cancer. This type of research into functional skin proteomics will provide a critical step toward understanding disease and developing successful therapeutic strategies.

Identification of Bacillus anthracis proteins associated with germination and early outgrowth by proteomic profiling of anthrax spores

The use of anthrax spores as a bioweapon has spurred efforts aimed at identifying key proteins expressed in Bacillus anthracis. Because spore germination and outgrowth occur prior to and are required for disease manifestations, blocking germination and early outgrowth with novel vaccines or inhibitors targeting critical B. anthracis germination and outgrowth-associated factors is a promising strategy in mitigating bioterror. By screening 587 paired protein spots that were isolated from dormant and germinating anthrax spores, respectively, we identified 10 spore proteins with statistically significant germination-associated increases and decreases. It is likely that proteins whose levels change during germination may play key roles in the germination and outgrowth processes, and they should be listed as priority targets for development of prophylactic and therapeutic agents against anthrax. The 31 new proteins identified in this study also complement an emerging proteomic database of B. anthracis.