Influenza vaccines: Past, present, and future

Area of Science:

• Immunology
• Vaccinology
• Virology

Background:

• Seasonal influenza causes significant global morbidity and mortality annually.
• Current influenza vaccines, developed since the 1930s, exhibit suboptimal protection rates, particularly in vulnerable populations like children and the elderly.

Purpose of the Study:

• To review the historical development of influenza vaccines.
• To analyze the immune responses elicited by existing vaccines and adjuvants.
• To propose future strategies for enhancing influenza vaccine efficacy across all age groups.

Main Methods:

• Literature review of influenza vaccine development and immunological studies.
• Analysis of vaccine-induced immune responses, including T helper cell type 1 and type 2 responses.
• Exploration of adjuvant applications in influenza vaccination.

Main Results:

• Despite decades of development, current influenza vaccines offer limited protection.
• Understanding of immune responses provides a basis for improved vaccine design.
• Adjuvants play a crucial role in modulating vaccine efficacy.

Conclusions:

• Future influenza vaccines should aim for balanced T helper cell type 1/type 2 immune responses.
• Development of broad-spectrum vaccines is necessary to counter influenza virus antigen shifts and drifts.
• The creation of safe and effective adjuvants is critical for advancing influenza vaccine technology.