Biology subjects

Joyner, G.

Publications and source records attributed to Joyner, G..

3 recordsLinked to original sources

bioRxiv2026

A double-blinded, placebo-controlled field trial of an OspA-based oral reservoir targeted vaccine against Borrelia burgdorferi

Lyme disease, caused by Borrelia burgdorferi and transmitted by Ixodes scapularis ticks, remains a significant vector-borne illness in the United States. Small mammal reservoirs, particularly Peromyscus leucopus, play a critical role in B. burgdorferi maintenance. Here we conducted a five-year, randomized, double-blinded, placebo-controlled field trial deploying an oral OspA-based reservoir targeted vaccine (RTV) across seven Maryland sites. Bayesian modeling provided estimates of vaccine impact on mouse anti-OspA antibody levels, nymphal tick infection prevalence (NIP), mouse infection rates, and seroconversion to B. burgdorferi in hunting dogs. RTV sites exhibited an estimated 10.5% proportional increase in protective murine anti-OspA antibody levels and a 15.4% reduction in NIP by year five. We also found a lower infection prevalence in mouse blood fed nymphal ticks (9.8%). RTV sites exhibited modest decreases in mouse infection prevalence and dog seroconversion rates were similar between groups. Our results indicate that anti-OspA antibody in vaccinated-infected P. leucopus reduced B. burgdorferi summertime larval infection prevalence, measured as NIP reductions the following spring. This suggests that OspA-based oral RTV reduces B. burgdorferi transstadial transmission within tick populations. Our findings advance development of reservoir targeted solutions for Lyme disease prevention. Further evaluation of impacts on incidental hosts is needed.

microbiology↗

bioRxiv2026

Homologous and Heterologous Immunization with a PIV5-Based Modified OspA Vaccine Confers Equivalent Protection Against Tick-Transmitted Borrelia burgdorferi

Vaccines targeting outer surface protein A (OspA) of Borrelia burgdorferi protect against Lyme disease by eliciting antibodies that neutralize spirochetes in the Ixodes scapularis tick midgut during engorgement before transmission occurs. We evaluated whether different delivery vehicles and administration routes for a modified OspA construct (OspABPBPk) differed in protective efficacy. Four groups of nine C3H-HeN mice were immunized with OspABPBPk delivered intranasally by live parainfluenza virus 5 (PIV5-OspABPBPk) or by subcutaneous administration of recombinant protein adjuvanted with aluminum hydroxide (rOspABPBPk) using three prime-boost regimens and a vector/adjuvant control: homologous intranasal PIV5-OspABPBPk (IN/IN), homologous subcutaneous rOspABPBPk (SC/SC), and heterologous intranasal PIV5-OspABPBPk prime/subcutaneous rOspABPBPk boost (IN/SC). Mice were challenged on day 90, approximately 2 months after the boost, with nymphal ticks infected with 19 strains of B. burgdorferi. All OspABPBPk-containing vaccines elicited high antigen-specific IgG antibody titers (geometric mean titers of 10^4-10^6, approximately 4 log10 higher than the control group), reduced B. burgdorferi loads in engorged nymphal ticks by 1.7-2 log10, neutralized B. burgdorferi motility in multi-strain cultures, and prevented recovery of viable spirochetes from tissues after tick challenge. While one mouse (1/9, 11%) in the heterologous IN/SC vaccinated group had detectable flaB DNA in tissues and seroreactivity to B. burgdorferi PepVF, culture of spirochetes from heart and bladder showed no evidence of active infection. Although homologous immunization produced the most consistent results in mice, different delivery vehicles and routes of immunization with OspABPBPk vaccines did not affect overall efficacy as assessed by recovery of viable B. burgdorferi from tissues.

microbiology↗

bioRxiv2025

Maternal Transfer of Vaccine-Induced Anti-OspA Antibodies in Peromyscus spp Protects Pups from Tick-Transmitted Borrelia burgdorferi

The efficacy and duration of passive immunity protection depends on maternal antibody levels and transfer efficiency. We investigated whether oral vaccination of Peromyscus leucopus dams with recombinant OspA-expressing E. coli could induce maternal transfer of anti-OspA antibodies and protect pups from Borrelia burgdorferi challenge. Dams were vaccinated until breeding pairs were created (i), until parturition (ii), and until pups were 2 weeks old (iii). Pups were challenged with nymphal I. scapularis-transmitted B. burgdorferi at [~] 4 weeks of age. Anti-OspA IgG were quantified in dams and pups, and anti-B. burgdorferi IgG were quantified in pups. B. burgdorferi burden was assessed by flaB qPCR in pups tissues [~] 4 weeks after tick challenge and viability of B. burgdorferi was assessed by culture of heart tissue. P. leucopus pups born to dams vaccinated until breeding had low serologic anti-OspA antibody and were not protected from tick transmitted B. burgdorferi infection. However, when dams vaccination extended until parturition and until pups were two weeks old, significant anti-OspA antibody transfer and protection from B. burgdorferi infection occurred. This was evidenced by absence of antibody to B. burgdorferi PepVF, absence of B. burgdorferi flaB DNA in heart and bladder tissues, and absence of flaB in culture from heart tissues from pups euthanized >9 weeks after birth. We show that transfer of anti-OspA antibodies from vaccinated P. leucopus dams to offspring prevents tick transmission and infection dynamics of B. burgdorferi in the major reservoir host of this spirochete in the United States. ImportanceThis study contributes to our understanding of how interventions based in reservoir targeted OspA vaccines designed to block transmission of B. burgdorferi from infected I. scapularis ticks may disrupt the enzootic cycle of this spirochete and reduce incidence of Lyme disease.

microbiology↗