A thermostable messenger RNA based vaccine against rabies

Area of Science:

• Vaccinology
• Virology
• Molecular Biology

Background:

• Rabies virus causes approximately 50,000 deaths annually, primarily in developing countries.
• Current rabies vaccines are costly and require a strict cold chain, limiting their availability.
• Lack of access to effective vaccines contributes to the high global mortality rate.

Purpose of the Study:

• To evaluate the temperature resistance and efficacy of a non-replicating mRNA rabies virus vaccine.
• To determine if the mRNA vaccine maintains protective capacity after prolonged storage at various temperatures.
• To assess the vaccine's performance under simulated cold chain interruptions.

Main Methods:

• Development of a non-replicating mRNA vaccine encoding rabies virus glycoprotein (RABV-G).
• Storage of the mRNA vaccine at temperatures ranging from -80°C to +70°C for extended periods.
• Testing vaccine efficacy by measuring rabies-specific virus neutralizing antibodies in mice.
• Challenging vaccinated mice with a lethal rabies infection post-storage.
• Simulating cold chain interruptions by storing the vaccine at oscillating temperatures (+4°C to +56°C for 20 cycles).

Main Results:

• The mRNA rabies vaccine demonstrated excellent stability across a wide temperature range (-80°C to +70°C).
• Storage did not compromise the vaccine's ability to induce virus neutralizing antibodies.
• Mice vaccinated with the temperature-stable vaccine were protected against lethal rabies challenge.
• Simulated cold chain interruptions did not impact the vaccine's immunogenicity or protective efficacy.

Conclusions:

• The mRNA rabies vaccine exhibits exceptional temperature resistance, making cold chain maintenance unnecessary.
• This stability suggests a potential solution for overcoming logistical barriers to rabies vaccine distribution.
• The findings support the development of more accessible and cost-effective rabies prevention strategies globally.