Ongoing Clinical Trials for Rabies

There are currently 5 clinical trials investigating rabies prevention and vaccination strategies. These studies are evaluating different methods of administering rabies vaccines, comparing pain levels in children, testing long-term immune responses, and examining how the body’s immune system responds to different vaccination techniques. The trials are taking place in Belgium and the Netherlands.

Clinical trial locations

• Belgium
  • Study Comparing Intradermal and Intramuscular Rabies Vaccination with Inactivated Rabies Virus for Patients Needing a Booster Dose
  • Study Comparing Intradermal and Intramuscular Rabies Vaccine Doses in Adults
  • Study on Pain and Usability of Rabies Vaccine Injection Techniques in Children Aged 4-14 Using Inactivated Rabies Virus (Strain Flury LEP)
• Netherlands
  • Study on BCG Vaccine and Rabies Virus (Inactivated) for Healthy Volunteers: Exploring Pre-Vaccination Immune Status and Its Impact on Vaccine Response
  • Study of Single-Dose Rabies Vaccine (Inactivated Flury LEP Strain) Immunity After Five Years: Testing Booster Response in Previously Vaccinated Adults

Study on Pain and Usability of Rabies Vaccine Injection Techniques in Children Aged 4-14 Using Inactivated Rabies Virus (Strain Flury LEP)

This study examines the experience of pain and ease of use when administering the Rabipur vaccine to children between 4 and 14 years of age. The research compares different injection methods, including intradermal (into the skin) and intramuscular (into the muscle) techniques.

Inclusion criteria: Children must be between 4 and 14 years old. A parent or legal guardian must provide written consent, confirming that both parents or guardians are aware of and agree to the child’s participation. The child and family must be prepared to follow the study schedule and attend multiple vaccination visits. The study is designed for children expected to travel to areas where there is a high risk of exposure to the virus, making preventive vaccination necessary.

Exclusion criteria: Children outside the specified age range cannot participate. Children with any medical conditions other than requiring preventive vaccination are not eligible. Children who cannot receive vaccinations or who are part of vulnerable populations requiring special protection are excluded.

Main focus: The primary goal is to measure pain levels children experience after receiving the vaccine. The study uses the Faces Pain Scale-Revised to assess children’s pain and a Numeric Rating Scale for parent observations. The research also evaluates how easy and safe different injection methods are to use. Blood tests will be conducted 28 days after the third dose to measure antibody levels, with a target of 0.5 IU/ml or higher considered adequate according to World Health Organization standards. Children will be monitored for side effects up to 7 days after each vaccination.

Investigational drug: The study uses Purified Chick-Embryo Cell-Culture Rabies Vaccine, which is made using cells from chick embryos to produce a safe and effective preventive measure. The vaccine stimulates the body’s immune system to produce antibodies against the virus.

Study of Single-Dose Rabies Vaccine (Inactivated Flury LEP Strain) Immunity After Five Years: Testing Booster Response in Previously Vaccinated Adults

This long-term study evaluates how well the body’s immune system remembers and responds to the vaccine five years after receiving a single dose. The research compares the effectiveness of a single-dose vaccination approach to a traditional two-dose schedule.

Inclusion criteria: Participants must be between 18 and 40 years old and in good general health as determined by the study doctor. They must be willing and able to follow all study procedures for 5 years and able to understand and sign an informed consent document. Participants must never have been exposed to the virus or received any vaccines for it in the past. They should not be likely to need preventive vaccination in the next 5 years due to work or other activities.

Exclusion criteria: Individuals with a history of vaccination within the past 5 years, known allergic reactions to vaccine components, current pregnancy or plans to become pregnant, active immune system disorders, or conditions that weaken the immune system are excluded. Those using immunosuppressants, who received blood products or immunoglobulins in the past 3 months, currently experiencing acute illness or fever, or with a history of serious vaccine reactions cannot participate. Participation in another clinical trial within the past 30 days, inability to commit to the full study schedule, history of uncontrolled chronic diseases, or current treatment with blood thinners also disqualifies candidates.

Main focus: The study tracks participants over five years, measuring immune response through blood tests that look for protective antibodies. Participants receive either a single dose or two doses initially, followed by additional doses after five years to simulate an exposure situation. The research aims to determine how effectively the body responds to booster shots when needed and how well protection lasts over time.

Investigational drugs: The study uses a vaccine as both pre-exposure prophylaxis (preventive measure) and simulated post-exposure treatment. The vaccine stimulates the immune system to produce antibodies, and the study examines how well participants’ immune systems respond to additional doses after the initial vaccination.

Study on BCG Vaccine and Rabies Virus (Inactivated) for Healthy Volunteers: Exploring Pre-Vaccination Immune Status and Its Impact on Vaccine Response

This research investigates how a person’s immune status before vaccination can predict how effectively they will respond to vaccines. While primarily focused on BCG vaccination for tuberculosis prevention, the study includes comparison with immune responses to the Rabipur vaccine to better understand different types of immune protection.

Inclusion criteria: Participants must be healthy volunteers between 18 and 55 years old, able to sign and understand the informed consent document, and willing to follow all study procedures and requirements. They must test negative for tuberculosis using the QuantiFERON-TB Gold In-Tube test and negative for HIV during screening.

Exclusion criteria: Individuals with acute illness at enrollment, those who received vaccinations within 4 weeks before the study, those with chronic medical conditions affecting the immune system, or those taking immunosuppressant medications cannot participate. People with a history of anaphylaxis to vaccines, pregnant or breastfeeding women, those who participated in another clinical trial within 30 days, those who donated blood within 8 weeks, those with known allergies to vaccine components, or those with a history of drug or alcohol abuse are excluded.

Main focus: The study examines the relationship between pre-vaccination immune status and post-vaccination immune responses. Healthy individuals who have never been exposed to tuberculosis receive the BCG vaccine, and their immune responses are carefully monitored through blood tests and possibly small skin biopsies. The research uses the mycobacterial growth inhibition assay (MGIA) to measure how effectively a person’s immune system can control bacterial growth. The study is scheduled to run from August 2025 to August 2027.

Investigational drugs: Participants receive two vaccines: BCG vaccine (containing Mycobacterium bovis, Danish strain 1331) and Rabipur (containing inactivated virus). The BCG vaccine stimulates the immune system to develop protection against tuberculosis bacteria, while researchers examine how immune status before vaccination might predict response effectiveness.

Study Comparing Intradermal and Intramuscular Rabies Vaccination with Inactivated Rabies Virus for Patients Needing a Booster Dose

This trial compares two different methods of administering the Rabipur vaccine: intradermally (just under the skin) and intramuscularly (into a muscle). The study focuses on understanding how these methods affect the body’s immune response, particularly T cells, which are important for fighting infections.

Inclusion criteria: Participants must be between 18 and 50 years old. For the Pilot Group, individuals must have completed or partly completed a vaccination schedule more than one month before joining, have a Body Mass Index of 30 or less, be able and willing to provide written consent, and not have any acute illness at enrollment. Women who can have children must agree to use contraception during the study and must not be pregnant or planning to become pregnant. For the Healthy Control Group, participants must be able to provide written consent, agree to share medical history and records when needed, and not have acute illness. For the Main Group, additional requirements include agreeing not to donate blood or receive other vaccinations for 30 days after each study vaccination.

Exclusion criteria: Individuals with active infection or illness, history of severe allergic reactions (especially to vaccines), those who are pregnant or planning to become pregnant, those with weakened immune systems, those taking immune-suppressing medications such as steroids, those who received another vaccine within a certain timeframe, those participating in another clinical trial simultaneously, those with a history of drug or alcohol abuse, or anyone with conditions that study doctors believe would make participation unsafe are excluded.

Main focus: The study measures the number of memory T cells that remain in the skin after vaccination, as well as other immune responses over time. Participants receive either the intradermal or intramuscular vaccine and are monitored through several months with a series of vaccinations and follow-up visits. The goal is to determine which vaccination method produces a stronger and more lasting immune response.

Investigational drug: The Rabipur vaccine contains an inactivated form of the virus. The study examines which administration method helps the body create more memory T cells, which help the body remember and fight off the virus if encountered again in the future.

Study Comparing Intradermal and Intramuscular Rabies Vaccine Doses in Adults

This clinical trial compares the effectiveness of two different vaccination methods in adults: intramuscular injection (into the muscle) and intradermal injection (just under the skin). The study uses the Rabipur vaccine containing an inactivated form of the virus, specifically the Flury LEP strain.

Inclusion criteria: Participants must be between 18 and 60 years old at the time of joining, willing to provide written informed consent, permanent residents of Belgium during the study period, and prepared to follow the study schedule including all required appointments and procedures. Women who can have children must be willing to use contraception for 1 month after each vaccination.

Exclusion criteria: Individuals who have had severe allergic reactions to any vaccine component, those with weakened immune systems, those currently participating in another clinical trial, pregnant or breastfeeding women, anyone with a history of vaccination within the past year, those with a history of infection, those who received blood products or immunoglobulins in the past three months, or anyone with conditions that study doctors believe would make participation unsafe or affect study results cannot participate.

Main focus: The study monitors participants to measure the level of protective antibodies in their blood at different times after vaccination. The research aims to determine if new vaccination methods are as effective as the standard method by assessing how many participants have enough antibodies to provide protection after receiving a booster dose. The study also evaluates safety to ensure the vaccine does not cause unexpected side effects. The trial is expected to continue until 2025.

Investigational drug: Purified Chick-Embryo Cell-Culture Rabies Vaccine is made using cells from chick embryos to grow the virus in a safe way. Once grown, it is killed and purified to make the vaccine. The vaccine helps the body build up antibodies, so if exposed to the virus, the body can fight it off more effectively. The trial tests whether the vaccine works equally well when given under the skin or into the muscle compared to the usual method.

Summary

The five ongoing clinical trials for rabies demonstrate a strong focus on optimizing vaccination strategies. A notable concentration of research is taking place in Belgium, with three trials, while the Netherlands hosts two studies. All trials use inactivated virus vaccines, with the Rabipur vaccine (containing the Flury LEP strain) being the most commonly studied product.

The research priorities include comparing different administration routes (intradermal versus intramuscular), evaluating long-term immune responses over five-year periods, and improving vaccination experiences for children by assessing pain levels. One study uniquely examines how pre-vaccination immune status might predict vaccine effectiveness, incorporating both BCG and rabies vaccines.

These trials reflect current efforts to make vaccination more comfortable for patients, particularly children, while maintaining or improving effectiveness. The studies also aim to establish whether single-dose or reduced-dose schedules can provide adequate protection, which could simplify vaccination protocols and improve accessibility in the future.