Evan Simpson

Evan Simpson advocated for an integrated approach to controlling diarrhea, including a vaccine.

Raising awareness about a vaccine's potential

In 2003, vaccines against rotavirus were poised to reach the global market, but surprisingly few people knew the virus’ name, let alone that it was the leading cause of severe diarrheal disease. “We’ve never heard of it,” ministers of health would say when PATH staff members began meeting with them to spread the word about the virus and the new vaccines.

But staff with the Rotavirus Vaccine Program, a program at PATH that included the World Health Organization (WHO) and the US Centers for Disease Control and Prevention, soon realized countries were well aware of their diarrheal disease problems. A vaccine against rotavirus would be a key step toward protection, as would other approaches.

PATH program officer Evan Simpson listened closely to public health officials, partnering with them to prioritize their countries’ needs and opportunities for control of diarrheal disease. Evan and his colleagues developed an integrated approach to diarrheal disease control—including adoption of the new rotavirus vaccine. As country leaders reviewed new data about the effect of rotavirus and the cost-effectiveness of vaccination, their interest grew.


In 2006, Nicaragua became the first country in the developing world to adopt rotavirus vaccine. Other countries soon followed. Their experiences now help other ministries of health make the decision whether to adopt rotavirus vaccine.

Evan recalls those early conversations as PATH began to build interest in a new vaccine:

When the Rotavirus Vaccine Program started, one of my responsibilities was to go to countries that we thought might be early adopters of vaccine and talk with ministries of health about rotavirus. They would often be sort of puzzled because most of them had never heard of rotavirus. They would either say it must not be a problem in our country because we’ve never heard of it. Or they would say, well, it sounds interesting but our bigger problem is diarrheal disease.

The conversation with countries about rotavirus vaccine actually started with a conversation about diarrheal disease, because that’s what they were familiar with, and in many instances that’s what they were struggling with.

It takes a toolbox

Developing a strategy to combat diarrheal disease means looking at all the available tools, Evan says:

We developed this concept of presenting the broad portfolio of new interventions for diarrhea control. That portfolio included rotavirus vaccine. It included zinc treatment and a new formulation of oral rehydration solution. We would include information or data about the importance of exclusive breastfeeding, vitamin A, and also some of the environmental issues, such as water, sanitation, and hygiene.

We would say to the countries, here’s the broad portfolio of interventions for diarrheal disease. Let’s work together to develop a national strategy that lays all of these out. Because there is no one vaccine, no one treatment, that’s going to solve the problem.

Continuing the dialogue

For countries considering a new vaccine, Evan notes, both the evidence and the local context are part of the conversation:

When we’re talking about a new vaccine, it’s important to put the vaccine in the local context. Countries, I think rightly so, don’t want to be dictated to about their public health agenda and their priorities, so it’s important to begin a dialogue, particularly for vaccine for a disease that’s relatively unknown.

PATH is seen as an honest broker. Our agenda is not to make money off a vaccine. And PATH has been active in the vaccine world for 20 years now. We have a reputation globally. A lot of our reputation is at stake in terms of how we successfully present this information without trying to coerce countries to make these decisions.

We did have instances where we presented the evidence and in conclusion the countries decided that it wasn’t what they wanted to do. That’s part of the process. Eventually I think most countries will adopt rotavirus vaccine as part of their routine immunization program. And for some countries, it’s never a matter of if, just a matter of when.

Next Delivering on vaccines’ promise

Photo: PATH/Patrick McKern.