Live Attenuated Vaccines for Life-Threatening Respiratory Viruses
Respiratory viruses are one of the biggest threats to human health. Vaccines are the most effective healthcare tool to combat infectious diseases and have saved more lives than any other type of medicine. Meissa is dedicated to creating safe, potent, stable, and accessible intranasal live attenuated vaccines that can prevent infection and disease. Meissa’s RSV and COVID-19 live attenuated vaccine candidates were developed using the company’s AttenuBlock platform.
Intranasal vaccines generate both mucosal (IgA) antibodies in the nasal cavity and antibodies that circulate in the blood (serum). In contrast, injected vaccines typically induce circulating but not mucosal antibodies. While circulating antibodies are important for preventing serious lung disease, mucosal antibodies are important for blocking infection and viral transmission. The potential to prevent viral transmission is a key advantage that intranasal vaccines have due to the mucosal immune response that is induced.
In a Phase 1 clinical trial, Meissa’s RSV vaccine candidate stimulated a strong mucosal IgA response in adults who already had circulating antibodies to RSV in their blood. These results were consistent with previous animal studies, in which Meissa’s RSV vaccine candidate stimulated strong mucosal IgA antibody and circulating antibody responses and prevented infection of both the upper and lower respiratory tracts. Collectively, these results warrant further development of our vaccine candidates by demonstrating both mucosal and systemic immunity that blocks infection and prevents disease.
