Chinese researchers recently showed that a vaccine against hepatitis E is effective for up to four and a half years.
So why haven’t you heard about it? The hepatitis E virus infects 20 million people a year globally, killing 56,600, according to the World Health Organization.
Yet, much like Ebola before the recent well-publicized outbreak in Africa, hepatitis E has been out of sight, out of mind in North America, for the most part.
But in today’s world of multiple military missions and jet-setting travelers, any disease can reach U.S. shores. Global efforts to eradicate diseases you may never have heard of, or that you think only spread in developing nations, do have an impact in developed countries.
Having an effective vaccine against hepatitis E is good news not only for South Asia, where it causes the most deaths, but in the United States too, even though there’s more concern here about hepatitis C.
Dr. Amesh Adalja told Healthline the United States does see a small number of hepatitis E cases.
“Can this disease come to the U.S.? The military is stationed all over,” said Adalja, an infectious disease specialist in Pittsburgh, Pennsylvania. “Having this vaccination is important, not only for the military, but for those who travel. And there are a handful of cases in people who haven’t traveled anywhere.”
Researchers at Xiamen University conducted a trial of the vaccine among more than 56,000 healthy adults between the ages of 16 and 65. During the 4.5-year study, 60 people contracted hepatitis E. Seven of them had been vaccinated; 53 had not. The study, published this month in the New England Journal of Medicine, concluded the vaccine is 86 percent effective.
Hepatitis E, a disease that damages the liver, is most common in areas where access to clean water is limited, such as war zones. Syrian refugees, for example, are pouring into crowded refugee camps where they are at risk. The disease can be especially harmful for pregnant women, whose babies also are at risk of contracting the disease.
“Because of the burden it has in Asia, that has driven the vaccine development,” said Adalja.
Developing a Defense Against Dengue
Adalja noted a vaccine for dengue, another killer disease that has made headlines in recent years, is also drawing near. He said a vaccine is currently in phase 3 clinical trials.
Demand for a dengue vaccine is fierce, Adalja said, saying it could produce “billions” of dollars in revenue. The disease affects 50 million people per year worldwide. It’s spread from person to person by mosquitoes, according to the World Health Organization.
Dengue cases have appeared in recent years in the United States in Key West, Florida, along the Mexico-Texas border, and in Hawaii, Adalja said.
Adalja has conducted research “focused on understanding the burden of dengue, the mechanisms to control it, and informing physicians about the need to be prepared to diagnose and treat dengue,” he told Healthline.
He said creating an effective dengue vaccine has been a challenge because it must offer balanced immunity against all four strains of dengue. Most people are infected with more than one strain at a time, Adalja said.
Adalja said an announcement about the results of the most recent dengue vaccine trial could come at anytime.
Vaccinating Against Deadly Diarrhea
Progress is also being made toward a vaccine to fight diarrhea-causing diseases such as rotavirus, Enterotoxigenic Escherichia coli, or ETEC, and shigella.
“Rotavirus is not a major burden in the U.S., we are so well vaccinated,” Adalja said. “There are efforts to make that the case through the world. [Diarrhea] is a leading cause of morbidity and mortality.”
Adalja said the work of organizations such as PATH, an international nonprofit aimed at improving global health, means vaccinations against diarrheal diseases are beginning to get to where they’re needed. PATH has received significant funding from the Bill and Melinda Gates Foundation, a major backer of vaccination programs worldwide.
Meanwhile, tuberculosis (TB) continues to be a global menace. Because of the low risk of contracting the disease in America, the TB vaccine isn’t in widespread use in the United States. Children in countries where TB is common often do receive the vaccine.
Children today may not hear stories about their grandparents spending time in tuberculosis sanatoriums, but the disease is still very much on the rampage. The emergence of multidrug-resistant TB infections in India, China, and Russia are a serious concern for public health authorities.
“A third of the world’s population is infected; it never went anywhere,” Adalja said. “In the U.S., we have it under good control because we are effective at diagnosing and treating it.”