Intranasal Gonorrhea Vaccine Candidate Announces Favorable Preclinical Data

Global interest in developing vaccines against Neisseria gonorrhoeae (NG) has been sparked by the increasing threat of gonococcal antimicrobial resistance and the number of new infections.

And according to the U.S. Centers for Disease Control and Prevention (CDC), over 600,000 cases of gonorrhea were reported in 2020, making it the second most common sexually transmitted infection in the United States. 

And the disease is known to be contracted repeatedly without apparently developing protective immunity.

To address this extensive health need, Intravacc today announced favorable preclinical data for Avacc 11®, the prophylactic intranasal gonorrhea candidate vaccine developed in partnership with Therapyx inc. 

The results of the candidate, a proprietary outer membrane vesicle (OMV) platform-based gonorrhea vaccine combined with encapsulated IL-12, showed protection against subsequent infection with NG.

In this study, mice were vaccinated via the intranasal route, and the results of this intranasal study were similar to the intravaginal vaccination route. Intranasal immunization resulted in high serum IgG, salivary IgA, and vaginal IgG and IgA anti-gonococcal antibodies when OMVs were administered with IL-12 ms.

The serum IgG and salivary IgA antibodies induced in male mice were similar to the response induced in female mice.

Gamma interferon (IFN-g) production by CD4 T cells from iliac lymph nodes was elevated after vaccination intranasally or intravaginally.

Female mice immunized with OMVs plus IL-12 ms by either route resisted challenge with NG to an equal extent, and resistance generated by intranasal immunization extended to heterologous strains of NG.

These results were published in the peer-reviewed journal MSphere of the American Society of Microbiology.

Dr. Jan Groen, Intravacc's CEO, commented in a press release on January 16, 2023, "Together with our partner Therapyx, we are very pleased with the preclinical data of the intranasal candidate vaccine Avacc 11®."

"This intranasal gonococcal vaccine is more suitable to fight gonorrhea infections, which are becoming increasingly resistant to antibiotic treatments."

In October 2022, Intravacc was awarded a $14.6 Million U.S. NIH/NIAID contract to develop this intranasal candidate gonorrhea vaccine further.

For the development of vaccines, Intravacc has designed and developed a platform based on outer membrane vesicles, spherical particles with intrinsic immune-stimulating properties.

The OMVs can be designed with immunogenic peptides and/or proteins that stimulate effective adaptive immunity.

The OMV carrier has been optimized to induce a more effective immune response against these newly introduced antigens.

Intravacc has also developed genetic tools to increase the yield of the OMVs, reduce toxicity and achieve the desired antigenic composition.

Intravacc's OMV platform is scalable and allows rapid and efficient modification of the antigen composition, either through genetic modification of the bacterial host or by associating antigens with stored OMVs.

As of January 2023,  there is no effective gonorrhea vaccine available in the U.S.