Introduction of Vaccinomics to Develop Personalized Vaccines in Light of Changes in the Usage of Hantaan Virus Vaccine (Hantavax®) in Korea

Safety and Immunogenicity of an Andes Virus DNA Vaccine by Needle-Free Injection: A Randomized, Controlled Phase 1 Study

BACKGROUND

Andes virus (ANDV), a rodent-borne hantavirus, causes hantavirus pulmonary syndrome (HPS). The safety and immunogenicity of a novel ANDV DNA vaccine was evaluated.

METHODS

Phase 1, double-blind, dose-escalation trial randomly assigned 48 healthy adults to placebo or ANDV DNA vaccine delivered via needle-free jet injection. Cohorts 1 and 2 received 2 mg of DNA or placebo in a 3-dose (days 1, 29, 169) or 4-dose (days 1, 29, 57, 169) schedule, respectively. Cohorts 3 and 4 received 4 mg of DNA or placebo in the 3-dose and 4-dose schedule, respectively. Subjects were monitored for safety and neutralizing antibodies by pseudovirion neutralization assay (PsVNA50) and plaque reduction neutralization test (PRNT50).

RESULTS

While 98% and 65% of subjects had at least 1 local or systemic solicited adverse event (AE), respectively, most AEs were mild or moderate; no related serious AEs were detected. Cohorts 2, 3, and 4 had higher seroconversion rates than cohort 1 and seropositivity of at least 80% by day 197, sustained through day 337. PsVNA50 geometric mean titers were highest for cohort 4 on and after day 197.

CONCLUSIONS

This first-in-human candidate HPS vaccine trial demonstrated that an ANDV DNA vaccine was safe and induced a robust, durable immune response. Clinical Trials Registration. NCT03682107.

Zoonotic Hantaviridae with Global Public Health Significance

Hantaviridae currently encompasses seven genera and 53 species. Multiple hantaviruses such as Hantaan virus, Seoul virus, Dobrava-Belgrade virus, Puumala virus, Andes virus, and Sin Nombre virus are highly pathogenic to humans. They cause hemorrhagic fever with renal syndrome (HFRS) and hantavirus cardiopulmonary syndrome or hantavirus pulmonary syndrome (HCPS/HPS) in many countries. Some hantaviruses infect wild or domestic animals without causing severe symptoms. Rodents, shrews, and bats are reservoirs of various mammalian hantaviruses. Recent years have witnessed significant advancements in the study of hantaviruses including genomics, taxonomy, evolution, replication, transmission, pathogenicity, control, and patient treatment. Additionally, new hantaviruses infecting bats, rodents, shrews, amphibians, and fish have been identified. This review compiles these advancements to aid researchers and the public in better recognizing this zoonotic virus family with global public health significance.

Association between predator species richness and human hantavirus infection emergence in Brazil

Hantavirus infection is a rodent-borne disease (RBD) transmitted by urine or feces (as the natural reservoirs) with an annual estimated worldwide incidence of ~150,000 cases. Previous ecological studies suggested that higher species richness of rodents could decrease the risk of RBDs in humans, because the regulatory pressure of predators could reduce contact among rodents, and between humans and rodents. Using surveillance data, we investigated the association of predator species richness with hantavirus infection emergence in 5562 Brazilian inland municipalities between 2007 and 2017. Multivariable logistic regression models were used for the analyses. Diurnal and non-diurnal predator species were independent explanatory variables in the models. Rodent species richness and demographic, socioeconomic, and environmental factors were used as covariates. During the study period, 1084 cases were reported in 429 municipalities. The results showed a reverse-U-shaped association between diurnal predator species richness and hantavirus infection emergence (odds ratio [OR] 0.463, 0.688, and 0.553 for the first [lowest], third, and fourth [highest] quartiles, respectively, using the second quartile as a reference), while higher non-diurnal predator species richness tended to be associated with higher emergence risk (OR 0.134, 1.065, and 2.708 for the first, third, and fourth quartiles, respectively). The difference in these associations illustrates the complexity of the effects of predator species richness on human RBDs, which require further investigation in follow-up studies. The results showed a close link between environmental factors and public health, emphasizing that the One Health concept should be employed to understand the dynamics of RBDs.

Current Challenges in Vaccinology

The development of vaccines, which prime the immune system to respond to future infections, has led to global declines in morbidity and mortality from dreadful infectious communicable diseases. However, many pathogens of public health importance are highly complex and/or rapidly evolving, posing unique challenges to vaccine development. Several of these challenges include an incomplete understanding of how immunity develops, host and pathogen genetic variability, and an increased societal skepticism regarding vaccine safety. In particular, new high-dimensional omics technologies, aided by bioinformatics, are driving new vaccine development (vaccinomics). Informed by recent insights into pathogen biology, host genetic diversity, and immunology, the increasing use of genomic approaches is leading to new models and understanding of host immune system responses that may provide solutions in the rapid development of novel vaccine candidates.