Guinea worm was eliminated in Mali in 2016, leaving just three countries with endemic infections. In those three countries, a mere 25 cases were recorded. In addition, the rate of cases identified before they could spread went up to 56 percent in 2016, from 36 percent in 2015. If we don’t see total Guinea Worm eradication in 2017, we will at least see it wiped out of Ethiopia and Sudan, both of which showed impressive progress in 2016.
Guinea worm has no treatment and no vaccine. It can only be prevented. Prevention takes the form of old-fashioned public health interventions. Communities received water filters, and learn to use them for all drinking water, every single time. People infected with Guinea Worm are taught not to enter public water sources, so they don’t allow the disease to infect the water source. This kind of work takes place person-to-person and household-to-household, and it is working.
Dengue fever is the most common mosquito-borne viral illness in the world. It causes severe pain and suffering in its victims, and can develop into fatal dengue hemorrhagic fever. It is found around the world, in Asia, Africa, Central and South America, and occasionally in North America. (There were two cases of Dengue fever in Florida in 2016.) It has been estimated that the annual economic impact of dengue fever is $2.1 billion in the Americas alone. Approximate 50-100 million dengue infections occur every year, and around 24,000 people die as a result. These numbers are poised to go up; the Dengue virus is expected to expand its territory as a result of climate change.
Last fall, the world’s first vaccine for dengue fever, Dengvaxia, finally came on the market in ten countries where the illness is prevalent. The vaccine is not perfect. It isn’t a good choice for children under the age of nine, and it works best for people who have already been infected with Dengue in the past. However, the vaccine 50—75% effective against dengue fever. In areas where dengue prevalence is high, it could reduce hospitalizations due to the disease by up to a third. That’s good news.
A better vaccine for shingles
Shingles is another painful, debilitating virus. It affects people who have been infected with chicken pox in the past. It causes intense pain for up to 90 days, and it is most common in people over the age of 50. There is a vaccine on the market for shingles right now, but the current vaccine ranges widely in effectiveness from just 18% to 70%. It also loses its effectiveness quickly, especially among the elderly people who are most at risk for the virus. In the US, approximate one out of three people will eventually develop shingles, and one out of two elderly people. It is painful for those who are infected, and often leads to hospitalizations that burden the health system. The pharmaceutical giant GSK is expected to bring a new vaccine to market in 2017. The new shingles virus has been found to be 90% effective, even after four years and among people over the age of 70. This could be a game changer in this horrendously debilitating disease.
Towards an HIV Vaccine
Although the global AIDS response has made tremendous progress in treating HIV, promoting condom use, and preventing disease transmission through antiviral drugs, the disease needs a vaccine if it’s going to come to an end. Community education can bring an end to Guinea Worm through education, but HIV education simply does not have the same kind of impact. Sexual behavior and intravenous drug use are far more difficult to change than water filtration.
November 2016 saw enrollment begin for the first advanced stage (Phase 3) trial of an HIV vaccine candidate in seven years. Known as study HVTN 702, this vaccine candidate has already shown promising results in Thailand. People who received the vaccine were 31% less likely to become infected with HIV during the 3.5 years of the study than those who did not receive it. We’ll see early stage results from the trial by the end of 2017.
A vaccine for malaria
2017 is going to be a huge year for vaccines. According to the World Health Organization, a new malaria vaccine called RTS,S is the most advanced malaria vaccine candidate the world has ever seen. It has already passed its Phase 3 trial, and it will be pilot-tested in three malaria endemic countries in sub-Saharan Africa in 2017. RTS,S was developed through a partnership between GlaxoSmithKline Biologicals and the PATH Malaria Vaccine Initiative, with support from the Bill & Melinda Gates Foundation and a network of African research centers that performed vaccine studies.
The vaccine has already been shown to work. It reduces the risk of malaria infection by 27% among babies. This seems like a small reduction, but malaria is very serious in infants. It is far more likely to lead to death in a baby than in an adult. The pilot testing will test the best approach to administering the vaccine. It must be received through a scheduled series of four doses to be effective, and the pilot projects will identify the best way to make sure babies get all four doses at the right time.