Why past malaria infections make vaccines work less well
Official title: Mechanisms of compromised CD8 T cell responses to vaccination in malaria experienced hosts
Funded at University of Iowa · NIH-11304077 · Data updated 2026-11-12
This project is testing ways to improve vaccine-driven CD8 T cell responses in people who have had malaria.
Quick facts
| Grant type | R01 grant |
|---|---|
| Study type | NIH-funded research |
| Funding institution | University of Iowa NIH-funded |
| Lab location | 1 site (Iowa City, United States) |
| Project start | June 24, 2024 |
| Project end | April 30, 2029 |
| Funding year | 2026 |
| Award (this year) | $765,058 |
| NIH project number | 5R01AI185725-03 |
| Project ID | NIH-11304077 on NIH RePORTER |
Who could benefit from this research
✓Could help
Ideal candidates for follow-up human work would be people living in malaria-endemic areas or those with a history of prior malaria infection when clinical studies are offered.
✕Less likely to help
People without prior malaria exposure or whose health issues are unrelated to malaria may not see direct short-term benefit from these findings.
What this research studies
Researchers will use a mouse model that mimics prior blood-stage malaria infection to understand why CD8 T cells respond poorly to radiation-attenuated sporozoite (RAS) vaccines in malaria-experienced hosts. The team will compare immune responses after RAS vaccination in mice with and without prior Plasmodium exposure, focusing on antigen presentation, CD8 T cell activation, and memory formation. Results will be related to known human outcomes from controlled human malaria infection (CHMI) and past clinical work to guide vaccine strategies for people living in endemic areas. The aim is to pinpoint immune mechanisms that can be targeted to restore protective liver-stage immunity.
Why it matters
Potential benefit: If successful, this work could lead to vaccines or immune-focused strategies that protect people in malaria-endemic regions more reliably.
How similar studies have gone: Radiation-attenuated sporozoite (RAS) vaccines have shown strong protection in malaria-naïve volunteers, but their reduced effectiveness in malaria-experienced populations is a less-tested problem.
Where this research is happening
-
University of Iowa
Iowa City, United States Active
Researchers
- Principal investigator: Harty, John T — University of Iowa
- Study coordinator: Harty, John T
Related research
Other NIH-funded projects on the same topics.
-
Malaria vaccine and infection: how the body’s early and later immune responses relate to protection
Researchers are studying how people’s immune systems respond to the malaria pre-erythrocytic stage, whether after vaccination or infection, to identify which responses are linked to protection.
-
Malaria prevention in Malawi: smarter analysis of transmission and RTS,S vaccination for kids
A large study in Malawi aims to understand how vaccination and mosquito control affect malaria risk in children, with a focus on how and where transmission happens.
-
Immune responses to an attenuated malaria vaccine
This project looks at how an attenuated Plasmodium falciparum sporozoite vaccine triggers immune cells and antibodies in people with and without prior malaria exposure.
-
Understanding how past malaria infections affect vaccine responses in children
This study is looking at how having malaria before affects how well kids in malaria-prone areas respond to vaccines, using a mouse model to help understand this better and find ways to make vaccines work better for them.
-
Understanding immune responses to malaria vaccination
This study is looking at how the immune system reacts to a malaria vaccine made from weakened parasites, and it's for people who want to help researchers understand what makes the vaccine work better for those who have and haven't had malaria before.
-
Digital malaria surveillance in Ethiopia to improve outbreak detection
A collaboration to add a malaria-specific digital module to an existing surveillance system in Africa to help detect and respond to outbreaks faster.
About this research
- This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
- Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
- For full project details, budget, and progress reports, visit the official NIH RePORTER page.