Supportive treatment of symptoms includes respiratory physiotherapy to remove secretions from the lungs by postural drainage, chest percussion, and vibration.

Treatment of symptoms usually includes use of artificial tears in the form of eye drops, increasing the humidity of the environment with humidifiers, and wearing wrap around glasses when outdoors.

There are indications based on variations in death rate between countries that early and effective treatment of symptoms (e.g., supportive care to prevent dehydration) may reduce the fatality rate significantly.