Epstein-Barr Virus (EBV) is a widespread human herpesvirus that infects most people globally at some point in their lives. While often a silent infection, EBV can lead to various health complications, ranging from mild illness to serious conditions. The development of a vaccine against EBV is a significant public health objective, aiming to prevent these diverse health issues associated with the virus.
Diseases Linked to EBV
EBV infection causes infectious mononucleosis, known as mono, with symptoms like fatigue, fever, sore throat, and swollen lymph nodes. Beyond this acute illness, EBV has been linked to more severe health problems, including certain cancers like nasopharyngeal carcinoma, a cancer of the upper throat, and specific lymphomas such as Burkitt lymphoma and Hodgkin lymphoma.
The virus is also associated with gastric cancer, a type of stomach cancer, and has a strong connection to autoimmune diseases, most notably multiple sclerosis (MS). EBV infection is a significant risk factor for developing MS, where the immune system mistakenly attacks its own tissues.
Strategies for Vaccine Creation
EBV vaccine development involves different approaches, broadly categorized into preventive and therapeutic strategies. Preventive vaccines aim to stop the initial infection or prevent the development of associated diseases, while therapeutic vaccines are designed to treat existing EBV-related conditions. A common target for preventive vaccines is the viral protein gp350, which plays a role in the virus entering B cells.
Other strategies involve targeting multiple parts of the virus to induce broader immune responses. Researchers are exploring various vaccine platforms for these candidates, including protein subunits, viral vectors, and mRNA technology. For therapeutic vaccines, targets like EBNA-1, a viral protein involved in maintaining the EBV genome in infected cells, are being investigated to control or eliminate latent infections.
Progress in Vaccine Development
Significant progress has been made in the development of EBV vaccines, with several candidates advancing into clinical trials. Moderna is developing an mRNA vaccine, mRNA-1189, in a Phase 1 clinical trial. This trial assesses the vaccine’s safety and ability to induce an immune response in healthy adults aged 18 to 30, and also in adolescents aged 10 to less than 18 years. Participants in the Eclipse Trial receive three injections over approximately six months and are monitored for about 18 months in total.
Another Moderna candidate, mRNA-1195, is also in a Phase 1 study to evaluate its safety and reactogenicity in healthy participants aged 18 to 55. Modex Therapeutics, in collaboration with Merck, has initiated a Phase 1 clinical trial for their vaccine candidate, MDX2201. This vaccine is designed to target four different EBV viral proteins, aiming for a more comprehensive immune response than approaches targeting gp350 alone. These trials are crucial steps in determining the safety and effectiveness of these promising vaccine candidates.
Benefits of an EBV Vaccine
A successful and widely available EBV vaccine holds the potential to significantly improve public health outcomes globally. Such a vaccine could substantially reduce the incidence of infectious mononucleosis, thereby lessening the burden of this common and sometimes debilitating illness. Beyond acute infection, preventing EBV could lead to a decrease in the occurrence of certain cancers linked to the virus.
This includes conditions such as nasopharyngeal carcinoma, gastric cancer, and various lymphomas, which represent a considerable global health challenge. Furthermore, a vaccine could potentially lower the risk of developing autoimmune diseases like multiple sclerosis, given the strong association between EBV and this condition. The broad public health implications of preventing these serious conditions highlight the transformative impact an effective EBV vaccine could have on global health.