Which vaccine is associated with respiratory droplets as a mode of transmission?

The correct answer is pertussis, which is associated with respiratory droplets as a mode of transmission. Pertussis, or whooping cough, is a highly contagious respiratory disease caused by the bacterium Bordetella pertussis. It spreads through the air when an infected person coughs or sneezes, releasing droplets that can be inhaled by others nearby.

Unlike some other conditions, pertussis specifically has a strong association with airborne transmission due to its ability to be spread through small respiratory droplets. This makes vaccination against pertussis particularly important not only for individuals but also for community immunity, helping to protect those who may be more vulnerable, such as infants who are too young to be fully vaccinated.

In contrast, while diphtheria, influenza, and tetanus all have respiratory components (in the case of influenza) or other modes of transmission, they are either less commonly associated with respiratory droplets (diphtheria, for example, primarily spreads through direct contact or droplets but is less airborne) or not transmitted this way at all (tetanus, which is caused by a bacterium found in soil and does not spread person-to-person). Hence, pertussis stands out in its specific association with respiratory droplet transmission