Malaria Vaccine Trials and Immunity

What are clinical trials?
A clinical trial is a test of a new medicinal product in human subjects. Before a new drug or vaccine can enter into clinical trials, it must undergo rigorous laboratory tests to establish its safety and then it has to be approved by the MHRA and COREC. All clinical trials also have to be approved by an Ethics Committee before they are carried out. Initial clinical studies of vaccines are carried out in small numbers (10 to 20) of healthy volunteers (phase 1) before going on to larger field studies of hundreds of volunteers (phase 2) and then studies of thousands of individuals (phase 3). The aims of vaccine studies are initially to demonstrate that the new vaccines are safe and that they can stimulate an immune response and ultimately to see whether they are effective in preventing disease.

Can anyone take part in the clinical trials?
No. Different clinical trials have different inclusion and exclusion criteria. We are looking for healthy adults aged between 18 and 50 who have never had malaria. Volunteers should live in the Oxford area and be able to travel easily to the Churchill Hospital where the trials are conducted. Any serious medical condition would exclude someone from volunteering. Women who are pregnant or intending to become pregnant cannot participate in these studies.

Are the candidate vaccines safe?
Before entering into clinical trials, the vaccines have to undergo rigorous toxicology testing in the laboratory and have to be approved for use by the MHRA (who regulate the use of all drugs in the United Kingdom). Vaccination may be associated with no side effects or symptoms. However, the vaccines may cause some transient redness and tenderness at the site of vaccination. Additionally volunteers may experience some short-lived flu-like symptoms. Clinical trials of similar vaccines indicate that these vaccines are likely to be safe.

Is the vaccine available to travellers who are going to malaria endemic areas?
No. We do not know at this stage whether the vaccines will offer protection against malaria and so travellers would need to take the relevant anti-malaria tablets if travelling to areas where malaria is prevalent.

Is the malaria challenge study (where volunteers are infected with malaria) safe?
We believe that these studies are safe. After infection with malaria there is an intensive period of follow-up with regular checks for malaria infection. As soon as any malaria parasites are seen in the blood, the volunteers are given the treatment. The treatment is 100% effective and this type of malaria does not recur. During this study, the clinical trial physicians are available 24 hours a day to answer any concerns of volunteers.

Does the malaria used in the malaria challenge study recur after treatment?
No. The malaria used in the challenge study is falciparum malaria and this does not recur. The strain used is a laboratory strain and is 100% curable by a number of anti-malaria drugs including Chloroquine. Other types of malaria can recur throughout a person's life such as vivax malaria but this is not used in these studies.

Can volunteers in the malaria challenge study pass on malaria to other people?
No. It is impossible to spread malaria from person to person by everyday contact. Malaria is a blood-borne pathogen and so volunteers infected with malaria should not give blood.

Why do volunteers take part in these studies?
There is no direct health benefit to volunteers taking part in these studies. However, the information that we gain from them is invaluable in the development of new malaria vaccines that may help to prevent millions of deaths each year if successful.

Who's in charge of the trial?
The Principal Investigator, Professor Adrian Hill, is in charge of the Malaria Vaccine Trials. The day-to-day running of the trials is done by the Research Physicians.

Do volunteers still need their own GP?
Yes. This is a clinical study of new malaria vaccines and volunteers should still see their GP for routine health matters. Volunteers are encouraged to discuss any of their concerns during the study with one of the trial physicians. The trial physicians are available 24 hours per day via the study pager.

If I was interested in taking part in a clinical trial what would I need to do?
You would need to contact the Malaria Vaccine Trials team (see contact us [link to relevant page]) to get more information about current studies so that you can decide whether you really want to take part. The trials team would ask you some questions to make sure that you were eligible to participate. If you decided to enter a study, then you would need to attend a screening visit. This is a general health check with a physical examination by a doctor and a blood test to make sure that you are fit to take part in the study.