Studies with live attenuated influenza vaccines

Area of Science:

• Virology
• Immunology
• Vaccinology

Background:

• Live attenuated influenza virus vaccines offer a promising approach to influenza prevention.
• Maintaining vaccine relevance against evolving influenza strains is crucial due to antigenic drift.

Purpose of the Study:

• To assess the safety, antigenicity, and transmissibility of inhibitor-resistant and temperature-sensitive live attenuated influenza virus vaccines.
• To develop recombinant vaccines against prevalent influenza strains to counter antigenic drift.

Main Methods:

• Administering inhibitor-resistant and temperature-sensitive live attenuated influenza virus vaccines to diverse volunteer groups.
• Creating recombinant vaccines using prevalent influenza virus strains over a five-year period.

Main Results:

• Both vaccine types demonstrated safety, antigenicity, and non-transmissibility in all volunteer groups.
• Recombinant vaccines were successfully developed to address new antigenic drifts.
• Inhibitor-resistant vaccines showed lower nasopharyngeal replication titers compared to temperature-sensitive vaccines.

Conclusions:

• Inhibitor-resistant and temperature-sensitive live attenuated influenza virus vaccines are safe and immunogenic.
• Recombinant technology is effective for updating influenza vaccines against antigenic drift.
• The characterized genetic defect of temperature-sensitive vaccines is an advantage, while lower replication titers of inhibitor-resistant vaccines are beneficial.