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Malaria Vaccine Study (GAP3KO)

Adults age 18 to 50 are needed for a malaria vaccine study.

We are looking for healthy adults age 18 to 50 to help test an investigational vaccine for malaria. You do not need to be a Kaiser Permanente member to be part of this research, which is called the GAP3KO Malaria Vaccine Study.

Lisa Jackson, MD, MPH, senior investigator at Kaiser Permanente Washington Health Research Institute, is the lead researcher for the study. Our funding comes from the U.S. National Institutes of Health.

Why is this research important?

Malaria is a significant global health problem. It infects 200 million people and causes about 438,000 deaths worldwide each year. Most cases and deaths are in children less than 5 years old in low income countries. Malaria is caused by a parasite, which is transmitted by mosquito bites. Efforts to develop an effective malaria vaccine have been happening for many years, but there is currently no licensed vaccine available in the United States.

The vaccine that is farthest along in development globally is the RTS,S vaccine, also known as Mosquirix™. That vaccine contains parts of the malaria parasite. It was first tested in adults in malaria-free regions. Adults who were given the vaccine were then exposed to malaria to see if the vaccine could prevent infection. Promising results from those trials led to the start of a large study involving 15,000 young children in Africa. The vaccine was modestly effective, reducing malaria cases by about one-third over a four-year period, but the protective effect lessened over time. Mosquirix will be given to children in three African countries under a pilot program starting in 2018. It is considered to be an important advance, but more effective vaccines are still needed.

What is the purpose of this study?

This study will look at how well a newer investigational vaccine prevents malaria infection in adults. The vaccine is made up of malaria parasites that have been genetically modified so that they cannot grow in the bloodstream and cause infection. The parasites are fed to mosquitoes raised in the laboratory, and the vaccine is given by the bite of those infected mosquitoes. To give each dose of vaccine, a study subject is bitten on the forearm by about 200 infected mosquitoes.

This method of giving the vaccine has already been tested in a clinical trial. This study will test whether this vaccine is safe, and also test whether it protects against malaria.

Who can be in the study?

This study will enroll healthy adults age 18 to 50. People who have medical conditions that affect the immune system or are taking medications that affect the immune system may not be in the study. There are other conditions that may make you ineligible for this study.

What will happen if you enroll in the study?

  • This study involves up to 75 scheduled study visits and 7 phone visits over a 20-month period. The total number of visits depends on the study group you are in.
  • There are three ways to be part of this study:
    • Subjects in Study Group 1 will receive 5 doses of the study vaccine. The first 4 doses will be 1 month apart and the fifth will be 2 months after the fourth dose. This group will have about 36 study visits and 5 phone visits during the 5 months after the first dose.
    • Subjects in Study Group 2 will receive 3 doses of the study vaccine. The second dose will be given 1 month after the first, and the third dose will be given 2 months after the second. This group will have about 24 study visits and 3 phone visits during the 3 months after the first dose.
    • Subjects in the control group do not receive the investigational vaccine. They participate only during the “malaria challenge” part of the study (described below).
  •  A malaria challenge is a standard part of malaria vaccine studies that is done to see whether the vaccine provides protection against the illness. This study will have two malaria challenges. This involves being bitten by five mosquitoes infected with fully infectious malaria parasites.
    • There is no blood test that can tell us if the vaccine works to create an immune response that prevents malaria. The malaria challenge is the only way to find this out. Without the malaria challenge, vaccines that show promise can’t go on to larger research studies in areas where malaria infection occurs.
    • The first challenge will be 4 weeks after the final vaccination for Study Groups 1 and 2, and the second will be 26 weeks after the first challenge.
    • Before each challenge, we will enroll a separate group of control subjects for that challenge. They will have about 20 study visits and 1 phone visit each over about 7–9 months.
  • After the vaccinations and the challenges, we will use a blood test called “PCR” to detect very low levels of malaria parasites in the blood. This testing will happen frequently, often daily, during the time that infection could occur.
  • If malaria infection occurs, treatment will be given with an oral medication (Malarone) that is effective against the malaria parasites used in the study.
  • The study visits will primarily be held in Kaiser Permanente Washington’s research clinic in the Metropolitan Park East building, near I-5 in downtown Seattle. The vaccination and challenge visits will be held at the Center for Infectious Disease Research facility in the South Lake Union area. Parking or bus fare will be provided.
  • During some parts of the study, visits will happen every day, including some weekends. Most visits will need to occur early in the morning, around 7 or 8 a.m.
  • To thank you for your help, you will receive $200 for each of the vaccination and challenge visits and $50 for each of the other study visits you complete. People who complete all visits as scheduled will receive between $1150 to $4800, depending on their study group.

Let us know if you might be interested

If you think you might want to be part of this study and would like more information, please email us at KPWA.vaccine@kp.org. Include your full name, phone number, and the best time to call, and we’ll get back to you soon.