Infection season begins: A respirator only protects when it fits properly

During the autumn and winter infection season, influenza, coronavirus infections and other respiratory infections become more common. 

Research in recent years has changed our understanding of how respiratory infections spread. WHO updated its terminology in 2024. Under this terminology, an infected person releases particles of different sizes containing pathogens simply by breathing and talking. These particles can travel with indoor airflows and cause infection when inhaled. Airborne transmission is also an important route by which common respiratory viruses spread.

Influenza vaccination is an effective way to prevent influenza and its severe consequences. However, vaccination does not prevent all infections or provide protection against other respiratory viruses. Vaccination should therefore be complemented by avoiding contact with others when ill, ensuring good ventilation and using an appropriate respirator when needed.

The INTO research project, jointly carried out by Tampere University of Applied Sciences, the University of Helsinki and Tampere University, examines ways to improve the prevention of airborne infections and the effectiveness of respirators. Funded by the Finnish Work Environment Fund, the project uses new methods to investigate the protective performance and fit of respirators.

Even a high-quality respirator can leak

In addition to the technical properties of a respirator, its protective performance depends on how well it fits and seals against the wearer’s face. If there are gaps between the respirator and the face, some of the air being breathed may bypass the filter.

The seal of a respirator matters during both inhalation and exhalation. A well-fitting respirator can reduce the wearer’s exposure to airborne pathogens while also reducing the release of pathogens from the respiratory tract into the surrounding environment.

Risks increase in healthcare and care work

Healthcare and care workers encounter many people during their working day and may be exposed to respiratory infections. At the same time, infections can spread from workers to patients and clients. Effective infection prevention is therefore a matter of both patient safety and occupational safety.

Preventing transmission is particularly important in settings where care is provided to older people, cancer patients, immune-compromised individuals or others who are vulnerable to severe respiratory infections. Cancer treatments, for example, can weaken the immune system, making the prevention of infections among people around the patient especially important.

Reducing employees’ own exposure helps prevent illness and supports continuity of services. Preventing sickness absence caused by respiratory infections is important from both a public health and an economic perspective, particularly when the infection season places additional pressure on healthcare services.

INTO investigates respirator performance in real-world situations

“For example, in healthcare, a well-fitting respirator can serve two purposes: reducing the worker’s own exposure and protecting vulnerable patients. In the INTO project, we are investigating how significant respirator fit is in real-world use,” says Project Manager Sampo Saari from Tampere University of Applied Sciences.

The first pilot studies of the INTO project will begin in early 2027. The researchers are developing measurement methods and practices to assess the actual protective performance, fit and leakage of respirators. These assessments will cover both inhalation and exhalation.

In addition to producing research-based knowledge, the project aims to develop training materials and practical guidance on respirator use, particularly for healthcare and care workplaces.

During infection season, remember at least these:

• Keep your seasonal vaccinations up to date.
• Avoid contact with others as soon as symptoms appear and when you are ill.
• Ensure good ventilation, particularly in crowded indoor spaces.
• Consider using a respirator in situations where the risk of exposure is elevated or where people vulnerable to severe infection are present.
• Make sure the respirator fits tightly against your face.
• Look for instructions online on how to put on, use and remove a respirator. For example: Pirkanmaa Wellbeing Services County’s instructions for FFP2 and FFP3 respirators

 
Contact:

Lotta Oksanen 
Postdoctoral Researcher
University of Helsinki 
lotta.oksanen [at] helsinki.fi (lotta[dot]oksanen[at]helsinki[dot]fi)  

Sampo Saari  
INTO Project Coordinator
Principal Lecturer | Built Environment and Bioeconomy 
Tampere University of Applied Sciences
sampo.saari [at] tuni.fi (sampo[dot]saari[at]tuni[dot]fi)   

More information about Enhancing the prevention of airborne infections through research and education (INTO) project on Tampere Universities' Community's website.