new vaccines clinical trials

How do the new vaccines address immunosenescence and compromised immune systems in older adults, and what clinical trials supported these design changes?

 

The new vaccines aim to improve protection in older adults by:

• Increased dosage: Higher antigen concentrations in vaccines, such as the Fluzone High-Dose Quadrivalent Inactivated Influenza Vaccine (FLUAD IV) with adjuvant, help overcome immunosenescence-related declines in antibody production.
• Adjuvants: Additives like MF59 in FLUAD IV enhance immune responses by stimulating the production of cytokines and activating immune cells, which can be impaired in older adults.
• Live attenuated vaccines: Vaccines like Shingrix (Recombinant zoster vaccine) and Zostavax (Live zoster vaccine) rely on pre-existing T cell populations to undergo a recall response, which may be less affected by immunosenescence.
• Targeting specific immune cell populations: Vaccines like Pneumovax 23-valent polysaccharide vaccine (PPSV23) and Prevnar 13-valent conjugated vaccine (PCV13) focus on stimulating B cells and antibody production, which may be more resilient to immunosenescence.

Clinical Trials Supporting Design Changes

Several clinical trials have informed the design of vaccines for older adults:

• Fluzone High-Dose Quadrivalent Inactivated Influenza Vaccine (FLUAD IV): Studies have demonstrated improved immune responses and protection against influenza in older adults compared to standard-dose influenza vaccines.
• Shingrix (Recombinant zoster vaccine): Clinical trials have shown that Shingrix is effective in preventing herpes zoster and postherpetic neuralgia in older adults, with a booster response observed in those with compromised immune systems.
• Pneumovax 23-valent polysaccharide vaccine (PPSV23): Research has demonstrated that PPSV23 induces robust antibody responses in older adults, including those with compromised immune systems.
• Prevnar 13-valent conjugated vaccine (PCV13): Clinical trials have shown that PCV13 elicits strong antibody responses and protects against pneumococcal disease in older adults, including those with compromised immune systems.

These design changes and supporting clinical trials aim to improve vaccine efficacy and protection in older adults, who are disproportionately affected by immunosenescence and compromised immune systems.