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Clinical Study FAQs

Frequently asked questions about vaccines and clinical trials conducted at the CIR.

Study Participation at the CIR

The Center for Immunization Research (CIR) is part of the Johns Hopkins University Bloomberg School of Public Health, Department of International Health.  The Center was established in 1985 by Mary Lou Clements-Mann.  For more than 30 years the CIR has provided leadership in the areas of early phase vaccine evaluation and vaccine education efforts.  CIR investigators primarily conduct Phase I and II safety, immunogenicity, and efficacy trials of new vaccine candidates. CIR faculty member Dr. Ruth Karron goes into more detail about the Center's work in the youtube clip below.

What is CIR?


What is a study participant?

A study participant is a person who volunteers to enroll in a clinical trial.  A participant can withdraw at any time without penalty or loss of any medical care that you would otherwise be entitled to receive.

How can I participate in studies at the CIR?

For more information on currently enrolling studies at the CIR, call our Project SAVE recruitment line at 410-955-7283 or visit the Join a Study page. 

What is my role if I participate in a CIR Clinical Study?

If you choose to participate in a clinical trial at the CIR, you will need to be screened to determine if you are eligible for the study.  In order to be screened you must sign the appropriate consent form after participating in the Informed Consent Process with CIR study staff.  The screening process may include:

  • Medical History collection
  • Specimen collection (i.e. blood, urine)
  • Physical Exam

Once you are enrolled in a study, you are responsible for the requirements of that study.


Will I be paid for screening?

No.  You will not be paid for the general screening for adult studies. You will be receive a parking sticker or MTA tokens to cover transportation expenses for this visit.


What is the difference between inpatient and outpatient studies?

Inpatient studies require admission to a clinical research facility for a specified period of time. Inpatient studies range from a few days to a few weeks.  CIR inpatient studies are conducted in our isolation facility on the Johns Hopkins Bayview Medical Center Campus.

Outpatient studies do not require admission to the inpatient unit. Participants come to the clinic for study visits following the research protocol visit schedule. 

Will I be paid if I enroll in a vaccine study?

Study participants receive compensation for their time.  The amount and payment schedule varies based on several factors that include:

  • Length of study
  • Inpatient vs. Outpatient
  • Number of study visits

You will receive more detailed information about study compensation during the screening process.


Can I enroll in a study if I am pregnant or planning to become pregnant?

No. If you are pregnant, planning to become pregnant or breastfeeding, you cannot participate in studies at the CIR.

What happens if I am a study alternate?

If you qualify to join a study you may be asked to participate in the event that another participant becomes unable to continue in the study.

Who will see my information if I participate in a clinical trial?
  • Study sponsor
  • Study personnel
  • Institutional Review Board (IRB)
  • Department of Health and Human Services (DHHS)
Who do I talk to if I have questions about vaccine clinical trials at the CIR?

Please contact us at:

  • 410-955-SAVE (7283) 

Inpatient, Outpatient and Challenge Studies at the CIR

Outpatient studies consist of visits to the center to conduct study procedures.  Study visits last from 30 minutes to 4 hours, depending on the scheduled study procedures.  A vaccination day visit can take up to 4 hours to complete, while a follow up visit may take 30-45 minutes.  Inpatient studies involve admission to the inpatient unit, where volunteers stay 24 hours a day for the entire inpatient period.  Most inpatient studies involve follow up visits after discharge from the inpatient unit.  Challenge studies are studies where the participants are given the virus or bacteria being studied under controlled conditions. 

What do inpatient studies at the CIR involve?

​​​​​​CIR inpatient studies are conducted at the CIR inpatient unit, located on the Johns Hopkins Bayview Campus.  Inpatient studies are conducted to:

  • Protect the study participants – some infectious investigational agents and/or challenge products can make people sick. Participants who become sick receive around-the-clock nursing care to keep them comfortable until they feel better.
  • Protect the public – some infectious investigational agents and/or challenge products can be transmitted to the general public. Study participants remain on the isolation unit until the risk of spreading the agent to the general public has passed.

Study procedures while on the unit may include:

  • Physical exams
  • Vital signs (i.e. blood pressure, temperature, respirations)
  • Specimen collection (i.e. blood, urine, stool)
  • Health surveys and interviews

Your length of stay on the unit will depend on the specific study you are enrolled in and can last anywhere from several days to several weeks.  The inpatient unit was designed to ensure the safety and comfort of study participants.  The dormitory style rooms have large windows for natural light.  Common areas provide a relaxing atmosphere and include large screen televisions, game tables, and lounge areas.   Computer access (including wifi), gaming systems, games, arts & crafts, and exercise equipment are also available to study participants during their stay on the unit.  All meals and snacks are provided.  Most meals are catered and there is additional food available for specialty diets, meals and snacks.  Once discharged, you may be required to return for a follow-up visit.  Compensation for your time and travel is provided for the inpatient stay and follow up visit(s).

Our study team members are experienced, dedicated and passionate research professionals who are committed to providing you with a positive research experience.  

What do outpatient studies at the CIR involve?

Outpatient studies are primarily conducted at the CIR Outpatient Clinic at Hampton House on the Johns Hopkins University East Baltimore Campus.  Outpatient studies are conducted to evaluate the safety, efficacy and immunogenicity of new investigational agents without admitting participants to an inpatient unit.  Outpatient studies are usually 6-12 months long and involve screening, investigational agent administration, and follow up visits.  These visits can last from 30 minutes to 4 hours, depending on the study and type of visit (i.e. follow up or vaccination day).  Participants who enroll in outpatient study procedures will:

  • Provide informed consent for study participation
  • Receive the investigational agent or placebo
  • Return to the center for follow up evaluations (which may include vitals, physical exams, and specimen collection)
  • Report changes in your health history to study staff (i.e. hospitalizations, Emergency Department visits, new disease diagnosis)
  • Report changes in your contact information to study staff (i.e. phone, email, address)
  • Complete study documents as instructed by study staff
  • Receive compensation for time and travel
  • Inform study staff immediately if you are running late, need to cancel or reschedule a visit, or if you want to drop out of the study
How do I screen for an inpatient or outpatient study?

Potential study participants must go through a screening process prior to enrolling in a CIR study. Typically, 2 screening visits are required to determine eligibility for enrollment. The CIR uses an independently approved screening protocol to conduct the first screening visit.  Screening visits that follow the initial screening visit use study specific procedures and will vary based on the particular study being screened for. Prior to the first screening visit, a pre-screening phone assessment is conducted to determine if potential participants are eligible for an in-person screening.  Screening visit procedures include:

  • ID Verification with photo (i.e. driver’s license, state ID, government issued document with name and date of birth, birth certificate)
  • Screening Protocol Informed Consent and Comprehension Assessment
  • Provide demographic information (name, address, date of birth, contact information)
  • Complete medical history form (and reproductive form for females only)
  • Vital signs and medical history review
  • Specimen collection (i.e. blood, urine, stool)
  • Transportation reimbursement (i.e. MTA tokens or parking validation sticker)

Participants are not paid for the first screening visit.  If enrolled into an inpatient or outpatient study, participants will receive compensation for additional screening visits.

What is a challenge study?

Challenge studies help researchers learn how a germ behaves in people and provide valuable information about potential paths to vaccine development.  These studies are important because they help us evaluate vaccines in the early stages to help determine whether or not they are going to work.  An example of a challenge study is giving volunteers shigella, which is a bacteria that causes diarrhea and makes many people sick (especially in developing areas of the world). 

We can test an investigational Shigella vaccine by giving it to study volunteers and a few weeks later admitting them onto the inpatient unit, giving them the Shigella germ and closely monitoring them to see if the vaccine keeps them from getting sick.  Being on the unit helps the study team to keep volunteers safe if they do become sick after given a challenge germ.




Will I be compensated?

Compensation for your time and travel will be provided for inpatient and outpatient trials at the CIR.  Study visit and compensation schedules are included in the study consent.  Your study coordinator will provide more specific information about the compensation schedule prior to enrollment.


Can I withdraw from a study?

Study participants may withdraw from a study at any time for any reason.  If you decide to withdraw, please contact your study coordinator or Principal Investigator immediately.

Understanding Vaccines

Vaccines are biological agents that stimulate an immune response in the body.  They are made from weakened, dead or even pieces of antigens that are introduced into the body in order to produce an antibody response.  An effective vaccine causes the immune system to produce these antibodies without producing significant signs and symptoms of the disease.

What are investigational vaccines?
Where did vaccines originate?

In 1796, Dr. Edward Jenner, a physician from England developed the first vaccine for the prevention of smallpox disease.  England was faced with a smallpox epidemic that killed 40% of people who contracted the disease.  Dr. Jenner observed that milkmaids who were infected with cowpox where protected from smallpox.  He obtained fluid from a milkmaid infected with cowpox and injected it into a healthy child.  Six weeks later, the boy was exposed to smallpox but did not become sick with the disease.   The term vaccination comes from the Latin word vaccina (cowpox).

Why are vaccines given?

Vaccines are given to reduce the mortality and morbidity rates caused by diseases and viruses.  The goal of the CIR is to develop vaccines that prevent and eradicate infectious diseases across the globe.

How do vaccines work?

Vaccines work by boosting the body’s own immune system.  It creates a “fake” infection that looks real enough to cause the body to produce antibodies against the disease.  If the body later encounters a real infection for the same disease, memory cells will start to fight it off, typically before it can cause any symptoms of illness.

How are vaccines administered?

Vaccines can be administered in the following ways:

  • Oral (by mouth)
  • Injection (intramuscular, intradermal, and subcutaneous)
  • Intranasal (sprayed into the nose)
  • Transdermal (patch on the skin)
Are there side effects or risks to getting vaccinated?

Like any medication, vaccines can cause side effects.  Most side effects associated with vaccines are minor.  Redness and swelling at the injection site, mild fever and headache are common side effects seen in vaccine recipients.  If you participate in a study, research staff will give you more detailed information about potential risks or side effects associated with the vaccine study.

Understanding Clinical Trials

There are four stages of clinical trials.  Phase I, Phase II, Phase III and Phase IV.  Each phase serves a specific purpose.  The Center for Immunization Research primarily conducts Phase I and Phase II trials to evaluate the safety, efficacy, and immunogenicity of investigational agents (vaccines).

Phase I

New investigational drugs or biological agents are tested in laboratories to find out if they meet basic safety standards before they are tested in humans.  These early studies are called pre-clinical trials.  After a new agent has met basic lab safety standards, in can be tested in people.  Phase I trials are the first to test new agents (or new indications for FDA approved agents) in people.

The purpose of a Phase I clinical trial is to evaluate the safety, proper dosage, and possible side effects of new investigational agents.  These trials usually enroll up to 100 healthy participants.  Sick people can have symptoms that could be confused with side effects of the investigational agent or it may make them sicker, so they typically are not enrolled in Phase I clinical trials.

Phase II

Investigational agents that have met basic safety standards in preclinical and Phase I trials can move on to Phase II clinical trials.  Phase II trials enroll larger groups of people to evaluate its safety and effectiveness for a particular indication.  They look at side effects and risks associated with the agent and enroll approximately 100-300 health participants and/or patients.  Testing the investigational agent in larger groups allows researchers to define the proper dosage and to learn more about the agent’s safety and possible side effects.  Phase II trials also allow researchers to learn about how well the agent actually works to prevent illness (efficacy).

Phase III

Phase III trials compare the investigational agent to commonly used treatments for the same indication.  Phase III trials are large and complex.  They often involve two or more groups of study participants who are randomized to determine if they will receive the investigational agent, the current treatment standard or a placebo.  Typically, the research team will not know which one the participant received to help maintain the integrity of the data gathered during the study.Phase III studies may enroll hundreds or thousands of participants across several study sites.  Studying the investigational agent in large numbers allows researchers to learn even more about the agent’s safety, side effects and ability to prevent or treat illness in diverse populations.

Investigational agents that meet safety requirements and works well can be submitted to the Food and Drug Administration (FDA) for licensure.  The FDA reviews the application and clinical trial data to determine if the agent is safe and effective.  Once the investigational agent is approved, it becomes available to the public by prescription or over-the-counter.

Phase IV

After a new agent is approved and available to the public there is still more that can be learned.  Phase IV studies (also known as post-marketing studies) are conducted after an investigational agent is approved by the FDA.  New benefits and/or side effects may be discovered during these studies.  Researchers may also be able to determine whether some groups of people have better results than others.

Phase IV studies are designed is several different ways.  Some trials enroll new participants (much like Phase III trials), while others monitor or collect data from existing records.  By tracking outcomes, the FDA can refine its recommendations about how the new agent can be used to help or protect the greatest number of people.