[Influenza vaccine and adjuvant]

Area of Science:

• Immunology
• Vaccinology

Context:

• Adjuvants enhance vaccine immunogenicity.
• Historically, mineral oil and aluminum salts have been primary adjuvants.
• Current research explores novel adjuvants like MF59 and AS series.

Purpose:

• To review the historical development and current applications of vaccine adjuvants.
• To discuss the efficacy and safety profiles of different adjuvant types.
• To highlight recent insights into adjuvant mechanisms involving innate immunity.

Summary:

• Adjuvants, derived from "adjuvare" (to help), are crucial for enhancing immunological responses to antigens.
• Aluminum salts have been mainstays since the 1930s, used in DTaP vaccines.
• Newer adjuvants like MF59 and AS series are employed in vaccines for influenza, hepatitis B, and HPV.
• Oil-adjuvanted vaccines may offer higher antibody responses but with increased adverse events, particularly local reactions.
• Studies on innate immunity suggest adjuvants activate immune cells, leading to cytokine induction and antigen presentation.
• Febrile reactions in children receiving alum-adjuvanted H5N1 vaccines warrant further investigation for safer vaccine development.

Impact:

• Provides a historical overview of adjuvant development and usage.
• Compares the immunogenicity and safety of various adjuvants.
• Underscores the importance of understanding innate immune pathways for future adjuvant design.
• Identifies areas for improvement in vaccine safety, particularly concerning febrile reactions.