Now and future influenza vaccines.

Area of Science:

• Virology
• Immunology
• Public Health

Background:

• Influenza remains a significant global health concern, presenting classical symptoms in the young but often going undetected in the elderly until serious complications like pneumonia arise.
• Influenza A and B viruses are the primary causative agents, characterized by their high mutation rates, necessitating continuous vaccine development and updates.
• Protective immunity against influenza is primarily mediated by antibodies targeting the hemagglutinin (HA) and neuraminidase (NA) surface antigens.

Purpose of the Study:

• To review the evolution and efficacy of influenza vaccines.
• To highlight the importance of annual immunization, especially for vulnerable populations.
• To discuss future directions in influenza vaccine technology.

Main Methods:

• Review of historical and current influenza vaccine technologies, including whole virus and split virus vaccines.
• Discussion of influenza surveillance systems for vaccine strain selection.
• Exploration of emerging vaccine platforms such as live attenuated virus vaccines, synthetic peptides, and genetically engineered antigens.

Main Results:

• Modern purification techniques have transformed egg-grown influenza viruses into safe, immunogenic, and effective killed-virus vaccines.
• Ongoing surveillance is essential for selecting appropriate virus strains for annual vaccine formulation.
• Current influenza vaccines, while effective, require annual administration, particularly for high-risk individuals.

Conclusions:

• Existing inactivated influenza vaccines are safe and effective, and their use should be maximized.
• Future influenza vaccine candidates, including live attenuated and novel antigen-based vaccines, show promise for improved administration and longer-lasting immunity, potentially requiring adjuvant enhancement.
• Continued efforts are needed to improve influenza prevention and control strategies globally.