COIOS
Behavioural science Item new preprint

Wastewater-triggered social media ads did not raise season-level vaccine uptake

A county-randomised trial in 40 New York State counties found an 11-week social media campaign triggered by community wastewater surveillance raised weekly COVID-19 vaccine doses and lowered weekly influenza doses during the campaign, with neither difference holding over the full season.

Forty New York State counties were randomised to receive, or not receive, an 11-week autumn 2024 social media campaign whose alerts were driven by community-level wastewater surveillance of respiratory viruses. The campaign generated 16.6 million impressions and 77,000 click-throughs; during it, intervention counties administered 76.7 more COVID-19 doses and 140.9 fewer influenza doses per 100,000 residents per week than control counties, but across the whole season neither difference persisted.

Why it is interesting: A rare randomised test of localised, data-triggered information as a lever on vaccination, and at season level it moved nothing.

Source
medRxiv, 21 September 2026
DOI
10.64898/2026.09.14.26362268
Type
Preprint
Design
County-randomised controlled trial, 40 New York State counties (20 intervention, 20 control), 11-week campaign, autumn 2024
Verdict
New finding
Driver
What changes behaviour at scale
Driver
Infectious disease and pandemics