Most mornings, I’d awake to an encouraging text message from Chang, who served as the main associate investigator for the study. “Your smear was negative!” his text would say.
A 31-year-old with a medical degree from Northwestern University, Chang worked late nights and early mornings, collecting blood, making smears and checking for early signs of the parasite in the volunteers. He hardly slept during the inpatient stays, running on adrenaline as he closely monitored the subjects.
“As the days went on and there were people still not getting malaria—that was really exciting,” he recalled recently. “Every day we thought: Are they going to get malaria or not? And each day that passed that they didn’t, we were thinking: There’s actually going to be a group of people who will make it through this. And that means the vaccine worked.”
But on the sixth night, I felt faintly nauseous, and knew that a headache was on its way—symptoms I normally would have brushed off if I hadn’t been so keenly aware of the parasites potentially eating away at my health.
After a female Anopheles mosquito deposits bloodthirsty Plasmodium parasites into a human host, the invaders travel to the liver, where they multiply before bursting into the bloodstream to feast on hemoglobin. Untreated victims may experience a burning fever, chills, crippling headaches and nausea. In severe cases, the parasites alter the surface properties of infected blood cells, causing them to stick to blood vessels and block the blood supply to vital organs, which can quickly lead to coma and death.
After I described my symptoms, which escalated by the hour, the nurses drew my blood and sent it to the lab for testing. The results confirmed my suspicions: I had malaria.
For three days, the nurses treated me with Malarone, a common anti-malarial drug that prevents the parasites from replicating. The drug’s effects were not immediate. At the outset, I endured eight seemingly endless hours of sweating and chills, which seemed unbearable at the time but were trivial in retrospect, given the months of torture that untreated malaria victims endure.
I remember requesting extra blankets, but they failed to curb my shivering. Later I found myself bathed in sweat. I couldn’t remember the last time I felt so miserable, but the experience was short-lived.
“It takes weeks and weeks for parasites to develop and multiply to a condition where you would really start worrying,” Chang said. “So most people might feel feverish, which you can treat, but they’re not going to have severe complications or die.”
When the sunlight burst through my hospital window the next morning, I woke feeling sleep-deprived and exhausted, but ultimately cured. I was troubled that the vaccine hadn’t worked, convinced that my body had somehow failed—and in so doing, crushed the hopes of the NIH team and squandered the millions of dollars that had gone into the study.
I was one of the first volunteers to succumb to the disease, and after three days of treatment, I was discharged. I returned to the quiet studio apartment I’d recently moved into in downtown Bethesda and reflected on the fact that I would be as susceptible to malaria as most of the world’s population if I traveled to any of the exotic places I hoped to visit one day.
Then, early in 2013, I received an unexpected call from Chang, who asked if I’d be willing to subject myself to malaria a second time. The NIH team was curious to see if the vaccine had any lasting effects on my body. I thought about the flavorless hospital food, the 11 days of freedom I’d sacrifice—and, of course, that torturous night after I contracted malaria. And then I agreed.
This time, I made it to Day 9 before the headaches and nausea set in.
This past summer, NIH hailed the PfSPZ study as a major success. Six of nine volunteers who received the same vaccine dosage I had were protected against the disease, and all six of those who received a higher dose were rendered immune. It remains unclear how long this immunity will last.
Meanwhile, 16 of the 17 individuals who received lower doses than I developed malaria, as did 11 of the 12 who weren’t vaccinated.
The doses used in the Phase I trial were small, as required by the Food and Drug Administration. But Seder is hopeful that with the highest dose administered—or perhaps an even higher dose—results can be achieved that could save hundreds of thousands of lives each year.
Meanwhile, other researchers continue to pursue alternatives. Numerous vaccines have been developed since the 1990s, but none has provided sufficient protection to get it to market. RTS,S, developed in the 1990s by GlaxoSmithKline and heavily funded by the Bill & Melinda Gates Foundation, may be the first to do so, even though its trial results are far lower than hoped.
At the same time, researchers at the Washington, D.C.-based PATH Malaria Vaccine Initiative and Inovio Pharmaceuticals are working together to develop a vaccine with genetically engineered DNA that’s meant to protect against the parasitic infection. Scientists at Johns Hopkins Malaria Research Institute and the University of Arizona have genetically modified lab mosquitoes to make them immune to the parasitic infection from malaria. And scientists at The Rockefeller University in New York have tried to engineer the insects to find humans less attractive.
Sanaria’s vaccine is the only one to use whole sporozoites, however. And Hoffman believes it could lead to immunity just as the bites of those 1,000 irradiated mosquitoes did decades ago. Sanaria’s PfSPZ vaccine is already scheduled to be used in at least four upcoming trials in Tanzania, Mali, Germany and at the Department of Defense. The VRC may conduct another study, as well, perhaps increasing the dose and changing vaccination intervals, Seder told me.
“I’m upbeat and cautiously optimistic that we’re on the right road here,” he said. “And I think a vaccine for malaria could be developed in our lifetime.”
My yearlong journey as a study volunteer had brought me to Seder’s sunlit, third-floor office, which overlooks the NIH campus where I used to come for my regular monitoring. Looking at the stacks of research papers scattered across his desk, I remembered the nurses and researchers I came to know, the early morning vaccination visits and Walter Reed’s insectary. I asked Seder what it all meant.
“It’s possible that you were in the first study on a path to something that could change the world,” he said.
Nicole Glass lives in Bethesda and is editor of the German Embassy’s newsletter. To comment on this story, email comments@moco360.media.
