Respiratory tract infections are common worldwide and place a considerable burden on sufferers and healthcare systems. Studies from the UK show that the early use of saline nasal spray in adults and children can reduce the duration of illness and the use of antibiotics. An isotonic (0.9%) saline solution was used in adults and a hypertonic (2.7%) saline solution in children.

Against this background, this cluster-randomized, controlled study investigates whether the early use of a hypertonic nasal spray can shorten the duration of illness in adults with respiratory tract infections. The study involves 13 general medical institutes with established research practice networks (e.g. BayFoNet, FoPraNet-BW, RESPoNsE).

A total of 200 GP practices will be randomly assigned to three groups: two intervention groups (frequent use: 6× daily; infrequent use: 2× daily, two strokes per nostril) and a control group with usual care. It is planned to include 3860 people without an acute cold who will be followed up for twelve months.

The duration of respiratory illnesses, possible psychological comorbidities, the number of sick notes, visits to the doctor and hospital admissions, travel times and waiting times for doctor's appointments will be investigated. In addition, antibiotics taken, vaccinations received and willingness to be vaccinated will be determined. A health economic analysis will identify potential cost savings. In addition, a process evaluation will examine which factors promote or hinder implementation in practice and how those affected experience the intervention.

The study officially starts on 01.01.2026.

Please do not hesitate to contact us if you have any questions!

PD Dr. rer. nat. habil. Linda Sanftenberg, M.Sc.

Research associate, extended institute management

Deputy Chairwoman of the National Action Alliance for Vaccination NABI