Optimizing immunization strategies using MCMV-based vaccine vectors

Ongoing Projects, Projects

Project title: UNIRI PROJECTS BY EXPERIENCED RESEARCHERS - Optimizing immunization strategies using MCMV-based vaccine vectors

Funding source: University of Rijeka

Project code: uniri-iz-25-105

Coordinator: Asst. prof. Maja Cokarić Brdovčak, PhD

Research Team:

      • Assoc. prof. Ilija Brizić, PhD
      • Jelena Železnjak, PhD
      • Assoc. prof. Berislav Lisnić, PhD
      • Magdalena Medved
      • Lucija Šakota

Total funding: 47.560,16 €

Project implementation period: 01.10.2025. - 30.09.2029.

Brief description: The development of effective vaccines against emerging viral pathogens, such as SARS-CoV-2, is a global priority. An effective vaccine should provide systemic immunity to protect against severe disease, while also stimulating mucosal immunity to prevent viral entry and reduce transmission. Although the COVID-19 vaccines have been effective in preventing severe disease, they do not offer complete protection against virus transmission and reinfection. Possible reasons are waning of protective immunity over time and the suboptimal mucosal immune response at the site of virus entry, as all currently approved vaccines are administered intramuscularly. To address these limitations, exploring alternative vaccine delivery methods and vectors may offer promising strategies for combating SARS-CoV-2.

In this project, we will compare two immunization approaches, intramuscular and intranasal, using recombinant cytomegalovirus-based vector vaccines encoding the SARS-CoV-2 spike protein. We aim to determine whether one immunization route is more effective than the other or whether a combination of both routes could provide better long-term protection and control of viral transmission. Cytomegaloviruses are excellent vector vaccine candidates due to their ability to induce robust and long-lasting immune response, making them a useful platform for the development of vaccines against respiratory pathogens such as SARS-CoV-2. Additionally, we will test a recombinant cytomegalovirus that expresses both the SARS-CoV-2 spike protein and a cellular ligand for the NKG2D activating receptor, which renders the virus attenuated. By comparing intramuscular and intranasal vaccination strategies, this study aims to identify the optimal route for inducing broad and durable immunity, which could be critical for controlling SARS-CoV-2 transmission and improving vaccination strategies. The results of this study will also contribute to the development of future vaccines, particularly those targeting mucosal immunity, to provide more effective protection against respiratory pathogens.