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Malaria Vaccine Study (PfSPZ-CVac)

Adults age 18 to 45 are needed for a malaria vaccine study.

We are looking for healthy adults age 18 to 45 to help test an investigational vaccine for malaria. You do not need to be a Group Health member to participate in this research, which is called the PfSPZ-CVac Malaria Vaccine Study.

Lisa Jackson, MD, MPH, senior investigator at Group Health Research Institute, is the lead researcher for the study, which is funded by the U.S. National Institutes of Health.

Why is this research important?

Malaria is a significant global health problem that infects 200 million people causing about 584,000 deaths worldwide each year. The vast majority of cases and deaths are in children less than 5 years old in sub-Saharan Africa. Malaria is caused by a parasite, which is transmitted by mosquito bites. Although there have been efforts to develop an effective malaria vaccine for many years, there is currently no licensed vaccine available.

The vaccine that is farthest along in development globally is the RTS,S vaccine, also known as Mosquirix™. This vaccine contains parts, or “subunits,” 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. Research continues on Mosquirix, which is considered to be a first generation vaccine that represents an important advance, but more highly effective vaccines are needed to achieve the goal of totally wiping out malaria.

What is the purpose of this study?

This study will evaluate how well a newer investigational vaccine prevents malaria infection in adults. Rather than just the parasite sub-units, this vaccine contains whole, live malaria sporozoites and can cause malaria infection. A sporozoite is the form of the parasite transmitted from the mosquito salivary glands into humans when the mosquito bites.

During the vaccination period, participants will also take weekly doses of an anti-malarial pill (chloroquine). This is done to allow the parasites in the vaccine to live in the body long enough to trigger a protective immune response, but not long enough to cause a malaria bloodstream infection.

This vaccination approach has been previously tested in clinical trials. The purpose of this study is to evaluate a more compressed vaccination schedule, giving the vaccine doses one week apart instead of several weeks apart to see if this could lead to immunity more quickly. The study will also evaluate how effective higher doses of the vaccine are when given on the compressed schedule.

Who can be in the study?

We are enrolling healthy adults age 18 to 45. 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?

  • If you are eligible and choose to enroll, you will be randomly assigned to get the investigational malaria vaccine or a placebo (salt water) injection. This means the decision will be made by chance—like flipping a coin. You will not know whether you got the vaccine or the placebo. Of every four people enrolled, three will get the vaccine and one will get the placebo.
  • This study involves 47 scheduled study clinic visits over about a six-month period. The visits will be held in Group Health’s research clinic in the Metropolitan Park East building, near I-5 in downtown Seattle. Parking or bus fare will be provided.
  • During some parts of the study, visits will be on a daily basis, including some weekends. Most visits will need to occur early in the morning, around 7 or 8 a.m.
  • You will receive an injection of either the investigational vaccine or placebo once a week for three weeks, while at the same time taking the chloroquine pills to prevent malaria infection. We will monitor your blood frequently during this time so that if malaria infection were to occur in spite of the pills, we can give treatment to cure the infection.
  • Ten weeks after the third injection, there will be a malaria “challenge,” which is a standard part of malaria vaccine studies that is done to see whether the vaccine provides protection against the illness. This involves receiving an injection of a smaller dose of the investigational vaccine without taking pills to prevent infection. There is no blood test that can be done to see if the vaccine works to create the 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 scale trials in areas where malaria infection occurs. To date, thousands of participants in malaria vaccine trials in the United States and other countries have had the malaria challenge.
  • After the challenge, we will monitor study participants’ blood tests daily during the time that infection could occur in order to detect it early (when a participant has no symptoms or only mild symptoms) so that we can give treatment to cure the infection. A blood test called “PCR” is used during the vaccination phase and after the challenge to detect very low levels of malaria parasites in the blood, allowing for prompt treatment if infection occurs.
  • If malaria infection occurs, we will initiate treatment with a three-day course of an oral malaria medication (Malarone) that is effective against the malaria sporozoites given for the vaccine and for the challenge.
  • As a thank you for your help, you will receive $200 for each of the four injection visits and $50 for each of the other 43 study clinic visits you complete.

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 vaccine@ghc.org. Include your full name, phone number, and the best time to call, and we’ll get back to you soon.

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