Journal of Mosquito Research, 2024, Vol.14, No.5, 264-275 http://emtoscipublisher.com/index.php/jmr 270 Nigeria’s experience has underscored the importance of continuous monitoring of immunity levels among vaccinated populations to inform policy decisions about the potential need for booster doses. 5 Innovative Approaches in Yellow Fever Vaccine Development With the persistence of Yellow Fever (YF) outbreaks and challenges related to traditional vaccine production and administration, new vaccine platforms are being explored to provide safer, more efficient, and scalable immunization solutions. These innovative approaches include DNA and RNA-based vaccines, nanoparticle and Virus-Like Particle (VLP) platforms, and multivalent vaccines that could potentially integrate protection against multiple flaviviruses. 5.1 DNA and RNA-based vaccines: advantages and potential DNA and RNA-based vaccines represent a significant advancement in the field of vaccinology, offering the potential for rapid development and production. Unlike traditional vaccines that rely on cultivating live or inactivated viruses, DNA and RNA vaccines utilize genetic material that encodes for antigens, allowing cells in the body to produce these antigens and trigger an immune response. This approach offers a flexible platform that can be adapted quickly to emerging variants or pathogens. DNA-launched vaccines, for example, have been investigated for yellow fever, demonstrating the ability to induce specific immune responses by using plasmid DNA encoding the full-length yellow fever virus RNA. This technology enables the replication of the viral RNA in vivo, initiating a controlled immune response. RNA-based vaccines, particularly mRNA vaccines, have gained attention due to their role in the COVID-19 pandemic, highlighting their capacity for rapid production and high efficacy. For yellow fever, the potential of RNA vaccines lies in their ability to produce strong humoral and cellular immunity with a lower risk of reversion to virulence compared to live-attenuated vaccines. This platform could be especially valuable in addressing vaccine shortages during outbreaks, as it can be scaled up faster than traditional egg-based production systems (Oreshkova et al., 2021). While promising, DNA and RNA vaccines face challenges such as the need for advanced storage conditions (especially for mRNA vaccines) and the requirement for delivery systems that enhance cellular uptake. Electroporation is commonly used to improve DNA vaccine uptake, but its scalability and application in low-resource settings remain to be addressed. 5.2 Nanoparticle and virus-like particle (VLP) vaccine platforms Nanoparticles and VLPs have emerged as versatile platforms for the development of safe and effective vaccines. VLPs are non-infectious, self-assembling structures that mimic the outer structure of viruses without containing their genetic material. This characteristic allows VLPs to stimulate strong immune responses while avoiding the risks associated with live virus vaccines. For yellow fever, VLP-based approaches have shown potential, particularly through the production of yellow fever VLPs using recombinant expression systems. Recent studies have demonstrated that purified yellow fever VLPs can be produced with high yields and retain structural integrity, making them suitable for use as vaccines (Lima et al., 2019). VLPs have also been explored in combination with novel adjuvant systems, such as nanoparticle-encapsulated Toll-like receptor (TLR) ligands, which can enhance the immune response by activating innate immune pathways (Kasturi et al., 2016). This approach has been shown to produce robust and durable immune responses, offering a promising route for long-lasting immunity with fewer doses. Nanoparticle-based platforms also provide the advantage of protecting vaccine components from degradation and improving delivery to target cells, making them an attractive option for future yellow fever vaccines (Dekevic et al., 2023). 5.3 Multivalent vaccines: integrating yellow fever with other flavivirus vaccines Given the co-circulation of several flaviviruses, such as dengue, Zika, and Japanese encephalitis, in many regions, there is growing interest in developing multivalent vaccines that can offer protection against multiple flaviviruses simultaneously. Multivalent vaccines can potentially simplify immunization schedules and improve coverage,
RkJQdWJsaXNoZXIy MjQ4ODYzNA==