Repeated high-dose (5 × 10(8) TCID50) toxicity study of a third generation smallpox vaccine (IMVAMUNE) in New Zealand white rabbits

Preclinical Pharmacokinetics, Biodistribution, and Acute Toxicity Evaluation of Caerin 1.9 Peptide in Sprague Dawley Rats

Caerin 1.9 is a natural peptide derived from the skin secretions of the Australian tree frog (Litoria) with broad-spectrum antimicrobial and anticancer bioactivity. It improves the efficacy of a therapeutic vaccine and immune checkpoint inhibitor therapy when injected intratumorally and inhibits TC-1 tumor growth when applied topically through intact skin in a TC-1 murine tumor model. This paper investigated the pharmaceutical kinetic profile, the tissue distribution, and the acute safety investigation of Caerin 1.9 peptide in Sprague Dawley (SD) rats. The results showed that subcutaneous injection of Caerin 1.9 at 100 mg/kg is safe and does not cause mortality or organ malfunction in the recipient rats. For the consecutive injection of F3 at 10 mg/kg, the peak concentration (C _max) of F3 displayed at 1 hr after injection in male rats was 591 ng/mL, the average drug retention time was 0.807 hr, T _1/2 was 4.58 hr, and AUC_0-last was 1890 h × ng/mL. In female rats, C _max was 256 ng/mL, with an average drug retention time of 2.96 hr, T _1/2 of 1.33 hr, and AUC_0-last of 740 h × ng/mL. The results showed that the concentration of Caerin 1.9 in the peripheral blood peaked at 1 hour. As injected concentration increased, T _1/2 extended, and C _max, AUC_0-last, and volume of distribution at a steady state all increased. After 14 days of repeated subcutaneous injection at 10.0 mg/kg, no accumulation of Caerin 1.9 in plasma was observed. The results of tissue distribution showed that the Caerin 1.9 is below the LC-MS/MS detection threshold at a minimum concentration of 40 ng/g. In conclusion, Caerin 1.9 is well tolerated in rats and could be used with current immunotherapies for better management of solid tumors and genital warts.

A vaccinia-based single vector construct multi-pathogen vaccine protects against both Zika and chikungunya viruses

Zika and chikungunya viruses have caused major epidemics and are transmitted by Aedes aegypti and/or Aedes albopictus mosquitoes. The “Sementis Copenhagen Vector” (SCV) system is a recently developed vaccinia-based, multiplication-defective, vaccine vector technology that allows manufacture in modified CHO cells. Herein we describe a single-vector construct SCV vaccine that encodes the structural polyprotein cassettes of both Zika and chikungunya viruses from different loci. A single vaccination of mice induces neutralizing antibodies to both viruses in wild-type and IFNAR^−/− mice and protects against (i) chikungunya virus viremia and arthritis in wild-type mice, (ii) Zika virus viremia and fetal/placental infection in female IFNAR^−/− mice, and (iii) Zika virus viremia and testes infection and pathology in male IFNAR^−/− mice. To our knowledge this represents the first single-vector construct, multi-pathogen vaccine encoding large polyproteins, and offers both simplified manufacturing and formulation, and reduced “shot burden” for these often co-circulating arboviruses.

Zika and chikungunya virus are co-circulating in many regions and currently there is no approved vaccine for either virus. Here, the authors engineer one vaccinia virus based vaccine for both, Zika and chikungunya, and show protection from infection and pathogenesis in mice.

Modified Vaccinia Virus Ankara: History, Value in Basic Research, and Current Perspectives for Vaccine Development

Safety tested Modified Vaccinia virus Ankara (MVA) is licensed as third-generation vaccine against smallpox and serves as a potent vector system for development of new candidate vaccines against infectious diseases and cancer. Historically, MVA was developed by serial tissue culture passage in primary chicken cells of vaccinia virus strain Ankara, and clinically used to avoid the undesirable side effects of conventional smallpox vaccination. Adapted to growth in avian cells MVA lost the ability to replicate in mammalian hosts and lacks many of the genes orthopoxviruses use to conquer their host (cell) environment. As a biologically well-characterized mutant virus, MVA facilitates fundamental research to elucidate the functions of poxvirus host-interaction factors. As extremely safe viral vectors MVA vaccines have been found immunogenic and protective in various preclinical infection models. Multiple recombinant MVA currently undergo clinical testing for vaccination against human immunodeficiency viruses, Mycobacterium tuberculosis or Plasmodium falciparum. The versatility of the MVA vector vaccine platform is readily demonstrated by the swift development of experimental vaccines for immunization against emerging infections such as the Middle East Respiratory Syndrome. Recent advances include promising results from the clinical testing of recombinant MVA-producing antigens of highly pathogenic avian influenza virus H5N1 or Ebola virus. This review summarizes our current knowledge about MVA as a unique strain of vaccinia virus, and discusses the prospects of exploiting this virus as research tool in poxvirus biology or as safe viral vector vaccine to challenge existing and future bottlenecks in vaccinology.