Medical Research Council - London Institute of Medical Sciences

Now in our 12th year of bringing you beautiful imagery from biomedical science every day

Spitting Images I Sneezy and Doc

Saliva stimulants, like cough drops, increase viral transmissibility potential

25 August 2021

Sneezy and Doc

Being caught in a blast when a friend sneezes is rarely pleasant. But thinking about the spread of viruses, what they’ve eaten recently might make a big difference. Using high-speed photography here, researchers capture liquid particles bursting from noses – in a rainbow timeline from purple (0 seconds) to white (0.5 seconds). Compared to a normal sneeze (top left) they found making saliva more viscous with food additives (top right, bottom left) changes a sneeze’s spread. Thicker mucus produces more large liquid droplets than small aerosol droplets. Aerosol droplets are more likely to carry small viral particles – like those from SARS-CoV-2 (cause of COVID-19) – and bob around in the air for longer. While wearing a mask (bottom right) confines a cough or sneeze, researchers believe future advice from doctors might be to avoid ‘cough drops’ which stimulate the release of excess saliva.

Written by John Ankers

Search The Archive

Submit An Image

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at with translations by the University of Valencia.