Tick BitesTICKMENCT05965635
The Uninfected Ixodes Scapularis Human Tick Challenge Model
A study testing Ixodus scapularis nymphs in people with Tick Bites and Immunity to Ticks, run by Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA) at 1 site in Netherlands.
Trial summary
An innovative way to prevent multiple tick-borne diseases is an anti-tick vaccine, i.e. targeting the vector to prevent transmission of pathogens from the tick to the host. The rationale for an anti-tick vaccine stems from a phenomenon coined tick immunity. Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Tick Bites, Immunity to Ticks
- What is being tested?
- Ixodus scapularis nymphs
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 11 participants
- Where
- 1 siteNetherlands
- Study dates
- 25 Jul 2023to 2 Mar 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Age: 18 years and older;
- Negative Borrelia VlsE1/pepC10 ELISA.
Who cannot join
- Known history of tick bites;
- Positive Borrelia serology (VlsE1/PepC10 ELISA);
- Known history or current suspicion on any tick-borne disease;
- Chronic skin condition affecting the arm skin;
- Inability to maintain the dressing for any reason;
- Known immunodeficiency or autoimmune disease;
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- Use of systemic immunomodulating drugs or chemotherapy, current or in the past;
- Chronic use of antibiotics;
- Unable to give informed consent or do not have a thorough command of the Dutch language;
- Refusal to participate in specimen collection and storage for future study related use;
- Pregnant or breastfeeding women;
- Not willing to use adequate contraception during the study period;
- Red meat allergy (both medically confirmed and self-reported);
- Use of investigational therapy and devices during the time of the study;
- Any other condition that, in the opinion of the investigator, would make the patient unsuitable for enrolment or could interfere with the patient participating in and completing the study.
Trial locations and contacts
1 site in 1 country.
Netherlands1 site
AUMC location AMC
Amsterdam-Zuidoost, North Holland, 1105 AZ
About this study
An innovative way to prevent multiple tick-borne diseases is an anti-tick vaccine, i.e. targeting the vector to prevent transmission of pathogens from the tick to the host. The rationale for an anti-tick vaccine stems from a phenomenon coined tick immunity. This study aims to show proof of concept that humans indeed develop immunity to ticks. Therefore subjects will be challenged three to four times with ticks reared in colony from a designated laboratory and that are exhaustively tested negative for various known tick-borne pathogens. Several tick feeding parameters will be evaluated to assess the development of tick immunity in the subjects. To this end, a total amount of ten ticks per challenge will be placed under a dressing placed on the forearm. The primary study endpoint is the tick feeding phenotype. Secondary parameters are signs of an immune response in the host; itch, redness, or other signs of a (local) immune response (blood and skin biopsies). All parameters, except for the skin biopsies, will be collected/evaluated after each tick challenge.
Read the detailed description
This will be an, single centre, experimental study. The design of the study is similar to a human challenge trial, with the important exception that the subjects in this study are not experimentally infected with a pathogen, but are exposed to well-characterized laboratory-reared uninfected nymphal Ixodes scapularis ticks.
Seven healthy human volunteers of >18 years old who have no history of known tick-bites or tick-borne diseases will be recruited. Subjects will undergo three to four tick challenges, consisting of five to six days per challenge with two weeks between the consecutive challenges. The total duration of participation is approximately five months for each subject. By making use of ticks from a laboratory-reared tick colony that have been, and are being, used in xenodiagnosis and tick challenge models in the USA and that are well tolerated minimizing the risks of the tick challenges. Regardless, the tick challenge can cause some discomfort because of possible local reactions and because the dressing must be kept dry for five to six days. The risk of infection with a tick-borne pathogen is negligible due to the fact that these ticks are exhaustively tested for various known tick-borne pathogens. Finally, risks are considerated of development of a red meat allergy or other allergic reactions negligible because no clear associations are known of I. scapularis ticks and red meat allergy. No serious adverse events (such as human infections or red meat allergy) have resulted from more than >100 challenges in the United States using this tick colony. There are no direct benefits of participation.
- Conditions
- Tick Bites, Immunity to Ticks
- Being tested
- Ixodus scapularis nymphs
- Keywords
- Tick bites, Ixodus scapularis, Tick Challenge model, Tick borne diseases, Tick immunity
- Medical subject headings
- Tick Bites, Tick-Borne Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Ixodus scapularis nymphsOther
Tick challenge
| Study group | Role | What they receive |
|---|---|---|
| Experimental | Experimental | Not described Receives: Other: Ixodus scapularis nymphs |
What is being measured
The primary outcome is the main question the study is designed to answer.
Tick weight
Tick weight in mg
Measured: Up to 1 week
Tick feeding molting success
Molting success rate
Measured: Up to 1 week
Tick survival
tick survival rate
Measured: Up to 1 week
Tick attachment
tick attachment rate
Measured: Up to 1 week
Secondary outcomes (4)
Signs of an immune response in the host: Itch
Itch
Measured: Up to 1 week
Signs of an immune response in the host: redness
Redness
Measured: Up to 1 week
Signs of an immune response in the host: other
Other signs of a local immune response (in blood)
Measured: 3 weeks
Signs of an immune response in the host: biopsies
Other signs of a local immune response (in skin biopsies)
Measured: 9 weeks
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jul 2023
- Study start25 Jul 2023
- Primary completion2 Mar 2026
- Study completion2 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Tick BitesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Model description
- Single centre, experimental study
- Masking
- None (open label)
- Enrolment
- 11 participants (actual)
Sponsor and investigators
- Lead sponsor
- Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
- Sponsor type
- University, hospital or other
- Collaborators
- ZonMw: The Netherlands Organisation for Health Research and Development
- Responsible party
- Principal investigator, prof. J.W.R. Hovius, MD, PhD, Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05965635
- Sponsor's protocol ID
- NL81259.018.22
- Acronym
- TICKME
- Status last verified
- Mar 2026
- First submitted
- 28 Mar 2023
- Last updated
- 24 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 24 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Uninfected Ixodes Scapularis Human Tick Challenge Model
- ClinicalTrials.gov ID
- NCT05965635
- Acronym / sponsor ID
- TICKME / NL81259.018.22
- Conditions
- Tick Bites, Immunity to Ticks
- Keywords
- Tick bites, Ixodus scapularis, Tick Challenge model, Tick borne diseases, Tick immunity
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 11 participants (actual)
- Lead sponsor
- Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA)University, hospital or other
- Collaborators
- ZonMw: The Netherlands Organisation for Health Research and Development
- Study start
- 25 Jul 2023 (actual)
- Primary completion
- 2 Mar 2026 (actual)
- Study completion
- 2 Mar 2026 (actual)
- First posted
- 28 Jul 2023 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
An innovative way to prevent multiple tick-borne diseases is an anti-tick vaccine, i.e. targeting the vector to prevent transmission of pathogens from the tick to the host. The rationale for an anti-tick vaccine stems from a phenomenon coined tick immunity. This study aims to show proof of concept that humans indeed develop immunity to ticks. Therefore subjects will be challenged three to four times with ticks reared in colony from a designated laboratory and that are exhaustively tested negative for various known tick-borne pathogens. Several tick feeding parameters will be evaluated to assess the development of tick immunity in the subjects. To this end, a total amount of ten ticks per challenge will be placed under a dressing placed on the forearm. The primary study endpoint is the tick feeding phenotype. Secondary parameters are signs of an immune response in the host; itch, redness, or other signs of a (local) immune response (blood and skin biopsies). All parameters, except for the skin biopsies, will be collected/evaluated after each tick challenge.
Detailed description
This will be an, single centre, experimental study. The design of the study is similar to a human challenge trial, with the important exception that the subjects in this study are not experimentally infected with a pathogen, but are exposed to well-characterized laboratory-reared uninfected nymphal Ixodes scapularis ticks.
Seven healthy human volunteers of >18 years old who have no history of known tick-bites or tick-borne diseases will be recruited. Subjects will undergo three to four tick challenges, consisting of five to six days per challenge with two weeks between the consecutive challenges. The total duration of participation is approximately five months for each subject. By making use of ticks from a laboratory-reared tick colony that have been, and are being, used in xenodiagnosis and tick challenge models in the USA and that are well tolerated minimizing the risks of the tick challenges. Regardless, the tick challenge can cause some discomfort because of possible local reactions and because the dressing must be kept dry for five to six days. The risk of infection with a tick-borne pathogen is negligible due to the fact that these ticks are exhaustively tested for various known tick-borne pathogens. Finally, risks are considerated of development of a red meat allergy or other allergic reactions negligible because no clear associations are known of I. scapularis ticks and red meat allergy. No serious adverse events (such as human infections or red meat allergy) have resulted from more than >100 challenges in the United States using this tick colony. There are no direct benefits of participation.
Study design
- Primary purpose
- Basic science
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
- Model description
- Single centre, experimental study
| Arm | Type | Receives |
|---|---|---|
| Experimental | Experimental | Other: Ixodus scapularis nymphs |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Age: 18 years and older;
- Negative Borrelia VlsE1/pepC10 ELISA.
Key exclusion criteria (15 listed)
- Known history of tick bites;
- Positive Borrelia serology (VlsE1/PepC10 ELISA);
- Known history or current suspicion on any tick-borne disease;
- Chronic skin condition affecting the arm skin;
- Inability to maintain the dressing for any reason;
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ixodus scapularis nymphsTick challenge | Other | Experimental |
Primary outcome
Tick weight
Time frame: Up to 1 week
Tick weight in mg
Tick feeding molting success
Time frame: Up to 1 week
Molting success rate
Tick survival
Time frame: Up to 1 week
tick survival rate
Tick attachment
Time frame: Up to 1 week
tick attachment rate
4 secondary outcomes
Signs of an immune response in the host: Itch
Time frame: Up to 1 week
Signs of an immune response in the host: redness
Time frame: Up to 1 week
Signs of an immune response in the host: other
Time frame: 3 weeks
Signs of an immune response in the host: biopsies
Time frame: 9 weeks
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 24 Mar 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Ixodus scapularis nymphs in people with Tick Bites and Immunity to Ticks, run by Academisch Medisch Centrum - Universiteit van Amsterdam (AMC-UvA) at 1 site in Netherlands.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 15 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 24 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Tick weight (time frame: Up to 1 week). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 24 Mar 2026.