# A Multivalent mRNA Vaccine to Prevent Transmission of Tick-bornePathogens

> **NIH NIH R41** · L2 DIAGNOSTICS, LLC · 2024 · $298,362

## Abstract

ABSTRACT
This Phase I proposal seeks to improve a novel vaccine for human use against pathogens
transmitted by the blacklegged tick, Ixodes scapularis. In previous studies, we proposed
that vaccine targeting of tick salivary proteins (Salps) critical for tick feeding would impair
tick feeding and consequently thwart the transmission of multiple tick-borne pathogens.
Our hypothesis is validated by the phenomenon of acquired tick-resistance wherein, upon
repeated tick infestations non-natural hosts such as rabbits, and guinea pigs mount a
robust immune response against tick Salps critical for tick feeding and this results in rapid
rejection of ticks and also prevents transmission of B. burgdorferi. Exploiting this
phenomenon, we identified several Salps that are avidly recognized by tick-resistant
animal sera.
Previous studies have successfully defined a 19Salp-mRNA (19ISP) cocktail that impairs
tick feeding, reduces tick engorgement, and blocks transmission of B. burgdorferi. These
results are now published in the journal Science Translational Medicine (Sajid et al, 2021,
13, eajb9827). Further experiments showed that a 12 mRNA-LNP subset is sufficient to
prevent tick feeding. However, erythema at the tick bite site in immunized animals raises
issues with the safety and commercial success of this experimental vaccine. In
preliminary experiments we have demonstrated that erythema is not sufficient to provoke
tick rejection. In this proposal we will further refine the antigen cocktail by eliminating
those antigens responsible for erythema and define a multiantigen mRNA vaccine that
blocks tick feeding and transmission of tickborne pathogens while eliciting no local
erythema at the bite site.

## Key facts

- **NIH application ID:** 10921580
- **Project number:** 1R41AI179587-01A1
- **Recipient organization:** L2 DIAGNOSTICS, LLC
- **Principal Investigator:** Erol Fikrig
- **Activity code:** R41 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $298,362
- **Award type:** 1
- **Project period:** 2024-05-01 → 2026-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10921580

## Citation

> US National Institutes of Health, RePORTER application 10921580, A Multivalent mRNA Vaccine to Prevent Transmission of Tick-bornePathogens (1R41AI179587-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10921580. Licensed CC0.

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