Transmission-blocking vaccines for respiratory viruses: from concept to clinic

Vaccine Insights 2026; 5(8), 411–416

10.18609/vac.2026.052

Published: 24 September
Commentary
Anika Singanayagam

Mucosal vaccines are widely proposed as a way to block respiratory virus transmission more effectively than systemic vaccines, yet supporting clinical evidence remains scarce. This Commentary outlines the obstacles to demonstrating transmission-blocking efficacy, from the absence of standardized correlates of protection to the limitations of animal and trial models, and considers how controlled human infection models, household studies, and field trials could help generate this evidence to support regulatory engagement and licensure.


01
Why mucosal vaccines are proposed to block respiratory virus transmission, and why supporting clinical evidence remains scarce
02
What hinders proof of transmission-blocking efficacy, from missing correlates of protection and mucosal immune markers to limited animal models and costly field trials
03
How CHIM, household studies, and cluster-randomized trials could generate evidence to support regulatory engagement and licensure
Mucosal Vaccines
Transmission-Blocking Vaccines
Respiratory Viruses
Controlled Human Infection Models
Correlates of Protection
Viral Shedding
Regulatory Pathways
Pandemic Preparedness