PIPELINE- RSV trial (ENG)

The international PIPELINE-RSV study investigates how to better protect babies from RSV (respiratory syncytial virus). RSV is a common virus that spreads easily. In adults and older children, RSV usually causes mild cold-like symptoms. However, in young babies, it can lead to severe respiratory tract infections and breathing difficulties.

This study aims to learn how well two approved options work to prevent RSV:

• Maternal RSV vaccination during pregnancy: Vaccines stimulate the immune system to produce antibodies and develop protection against a specific pathogen. When a pregnant woman receives the RSV vaccine, antibodies can be transferred to her baby, providing protection during the first months of life.
• RSV monoclonal antibody (mAb) for babies: Monoclonal antibodies are specially designed antibodies that help prevent or fight infections. The RSV monoclonal antibody is administered to the baby after birth and provides direct protection against RSV.

Several preventive options are currently available to protect babies against severe RSV disease. Although both the maternal RSV vaccine and the infant RSV monoclonal antibody protect babies against RSV, neither gives 100% protection and over time, the protection provided by both diminishes.

This study aims to improve our understanding of how the different RSV prevention strategies work and whether combining them may provide additional benefits. We will also investigate how the immune systems of mothers and babies respond to these preventive strategies.

The results may help improve RSV prevention in young babies and increase our understanding of how protection against RSV develops.

If you participate in the study:

• you will receive the RSV vaccine during pregnancy and/or your baby will receive an injection with the RSV monoclonal antibody.

• a nasal swab will be collected whenever your baby develops cold-like symptoms, until your baby reaches 12 months of age.

• follow-up visits will be scheduled for you and your baby:
  • at birth
  • when your baby is 2 or 4 months old;
  • when your baby is 6 months old;
  • when your baby is 12 months old.

• during these visits, small samples of blood, breast milk, nasal fluid and saliva will be collected from you and your baby. These samples will help us better understand how protection against RSV develops.

• you will be asked to complete online questionnaires about study-related topics, including your views on vaccines, your experiences with our trial procedures and your motivation for joining the trial.

We are looking for 90 pregnant women and their babies to take part in this study. Participants will be assigned to one of the following three groups:

1. RSV vaccine group: Mothers will receive the RSV vaccine during pregnancy
2.   mAb group: Babies will receive the RSV monoclonal antibody after birth.
3.   RSV vaccine + mAb group: Mothers will receive the RSV vaccine during pregnancy and their babies receive the RSV monoclonal antibody at around 4 months of age.

You may be eligible to participate if you:

• are pregnant (between 28 and 36 weeks),
• are expecting a single baby,
• have an expected delivery date during the RSV season, i.e. between early October and the end of March,
• are in good general health,
• are of legal age (≥ 18 years old).

Participation in the study will be possible from September 2026 onwards. When you participate, you will be followed up during your pregnancy and subsequently together with your baby until your baby reaches 12 months of age.

The PIPELINE-RSV study is part of the larger European “PIPELINE” project (Pregnancy and Infant PrEparedness pLatform IN Europe), which investigates the prevention and treatment of infections in pregnant women and infants.

The PIPELINE-RSV study is being conducted in Belgium, the Netherlands, Switzerland and the United Kingdom and will include about 1,500 pregnant women and their babies. A comparable trial is being executed in France. The results of both trials will be analysed together.

The PIPELINE-RSV trial is sponsored by the Penta Foundation ETS and is funded by the European Union (Project Grant Agreement Number 101155852).

For more information about the wider project, please visit the PIPELINE-RSV project website: https://pipelineproject.eu/rsv-study/.