Intranasal vaccine for Lyme disease provides protection against tick transmitted Borrelia burgdorferi beyond one year.

Strategies for disease control are necessary to reduce incidence of Lyme Disease (LD) including development of safe vaccines for human use. Parainfluenza virus 5 (PIV5) vector has an excellent safety record in animals and PIV5-vectored vaccines are currently under clinical development. We constructed PIV5-vectored LD vaccine candidates expressing OspA from B. burgdorferi (OspAB31) and a chimeric protein containing sequences from B. burgdorferi and B. afzelii (OspABPBPk). Immunogenicity and vaccine efficacy were analyzed in C3H-HeN mice after prime-boost intranasal vaccination with live PIV5-OspAB31 or PIV5-OspABPBPk, subcutaneous (s.c.) vaccination with rOspAB31+Alum, and the respective controls. Mice vaccinated intranasally with live PIV5-AB31 or PIV5-ABPBPk had higher endpoint titers of serum antibody against OspAB31 at 6- and 12- months post vaccination, compared to mice vaccinated s.c. with rOspAB31. Neutralization activity of antibody was maintained up to 18-months post-immunization, with the response greater in live PIV5-delivered OspA vaccines, than that induced by s.c. rOspAB31. Challenge with infected ticks carrying 10-19 strains of B. burgdorferi performed at 4-, 9- or 15-months post-immunization showed increased breakthrough infections in mice vaccinated with s.c. rOspAB31 compared to intranasal PIV5-AB31 or PIV5-ABPBPk at 9- and 15-months, as determined by quantification of serologic antibodies to B. burgdorferi proteins as well as flaB DNA in tissues, and by visualization of motile B. burgdorferi in culture of tissues under dark field microscope. These findings indicate that immunization of mice with PIV5 delivered OspA generates immune responses that produce longer-lasting protection ( > 1 year) against tick-transmitted B. burgdorferi than a parenteral recombinant OspA vaccine.

A parainfluenza virus 5 (PIV5)-vectored intranasal vaccine for Lyme disease provides long-lasting protection against tick transmitted Borrelia burgdorferi in mice.

Lyme disease (LD) is the most prevalent vector borne disease in North America and Europe and its geographic range continues to expand. Strategies for disease control are necessary to effectively reduce incidence of LD including development of safe vaccines for human use. Parainfluenza virus 5 (PIV5) vector has an excellent safety record in animals and PIV5-vectored COVID-19 and RSV vaccines are currently under clinical development. We constructed PIV5-vectored LD vaccine candidates expressing OspA from B. burgdorferi sensu stricto (OspAB31) and a chimeric protein containing sequences from B. burgdorferi and B. afzelii (OspABPBPk). Immunogenicity and vaccine efficacy were analyzed in C3H-HeN mice after prime-boost intranasal (IN) vaccination with PIV5-OspAB31 and PIV5-OspABPBPk, subcutaneous (SC) vaccination with rOspAB31+Alum as well as the respective controls. Mice vaccinated with either PIV5-AB31 or PIV5-ABPBPk intranasally had high endpoint titers of serum antibody against OspA antigen beyond 1 year post vaccination, similar to levels detected in mice vaccinated SC with rOspAB31. Flowcytometric analysis of spleen cells at 9-months post-immunization demonstrated that immunization with the intranasal PIV5 vaccine candidates led to an overall increase in the number of memory B cells, cytotoxic T and cytotoxic effector T cells compared to SC groups. Borreliacidal activity measured by neutralization assay was maintained up to 18 months post-immunization, with the response greater in intranasal PIV5-delivered OspA vaccines, than that induced by SC rOspAB31. Challenge with infected ticks (10-19 strains of B. burgdorferi) performed at 4-, 9- or 15-months post-immunization showed increased breakthrough infections in mice vaccinated with SC rOspAB31 compared to IN PIV5-AB31 or IN PIV5-ABPBPk at 9- and 15-months, as determined by qPCR of B. burgdorferi in tissues, culture of B. burgdorferi from tissues, and antibodies against B. burgdorferi protein VIsE. These data demonstrate that intranasal PIV5-based immunization is superior to parenteral immunization with the same recombinant protein and provides long-lasting protection (> 1 year) against Lyme disease.

Intranasal parainfluenza virus type 5 (PIV5)-vectored RSV vaccine is safe and immunogenic in healthy adults in a phase 1 clinical study.

Respiratory syncytial virus (RSV) can lead to serious disease in infants, and no approved RSV vaccine is available for infants. This first in-human clinical trial evaluated a single dose of BLB201, a PIV5-vectored RSV vaccine administrated via intranasal route, for safety and immunogenicity in RSV-seropositive healthy adults (33 to 75 years old). No severe adverse events (SAEs) were reported. Solicited local and systemic AEs were reported by <50% of participants and were mostly mild in intensity. Vaccine virus shedding was detected in 17% of participants. Nasal RSV-specific immunoglobulin A responses were detected in 48%, the highest level observed in adults among all intranasal RSV vaccines evaluated in humans. RSV-neutralizing antibodies titers in serum rose ≥1.5-fold. Peripheral blood RSV F-specific CD4+ and CD8+ T cells increased from ≤0.06% at baseline to ≥0.26 and 0.4% after vaccination, respectively, in >93% participants. The safety and immunogenicity profile of BLB201 in RSV-seropositive adults supports the further clinical development of BLB201.