Recent Developments in the Ebola Outbreak
With all the public hysteria over Ebola making headlines, it is easy to overlook the recent favorable developments in the fight against this deadly virus. Here are five encouraging news items:
1. Forty-eight people who had contact with Texas Ebola patient Thomas Eric Duncan before he was hospitalized in Dallas can breathe a sigh of relief. Those 48 contacts, including four family members who shared a small Dallas apartment with Duncan, have completed the 21-day observation period without falling ill and are no longer at risk of the disease. Ten of the 48 people were considered to be at high risk because of their close contact with Duncan. According to the World Health Organization, 95% of confirmed Ebola cases have an incubation period in the range of 1 to 21 days. (Note that 3% of confirmed cases have an incubation period of up to 42 days.)
2. The Obama administration has announced America’s first Ebola-related travel restrictions. Currently, there are no direct flights from the three West African Ebola hotspots (Liberia, Sierra Leone, and Guinea) to the United States. However, passengers who have been to these countries in the last 21 days and who travel through foreign airports will now be required to first enter the U.S. through one of five airports. These international airports are: JFK, Newark, Dulles, Atlanta, and Chicago. To protect the American people from Ebola, these airports will make sure all recent travelers to Liberia, Sierra Leone, or Guinea are subject to basic tests for fever and will face questioning on possible exposure to the disease.
There is a growing social media chorus calling for an outright ban on all travel from West Africa to the United States. Public health experts feel this approach would be counterproductive for the following reasons:
- People of means will still be able to get to the U.S. by flying through intermediary countries to disguise their true travel plans.
- A travel ban would encourage people to lie about where they have been. It is better to let people into the U.S. through the five portal airports so that these people can be identified, screened, and tracked.
- The U.S. will not truly be safe until the Ebola problem has been addressed in West Africa. A travel ban would discourage international volunteers from helping out in Liberia, Sierra Leone, and Guinea. Volunteers need to know they can easily get out of these countries when circumstances dictate it.
3. The World Health Organization says that efforts are on track to distribute an experimental Ebola vaccine in West Africa in January. Two potential vaccines are currently being tested for safety in people. One vaccine is being developed by GlaxoSmithKline and it has already been tried on a small number of volunteers in the U.S., Europe and Africa. The other vaccine is a Canadian vaccine which has been licensed to NewLink Genetics in Ames, Iowa. This vaccine is being tested in people at the Walter Reed National Military Medical Center and the National Institutes of Health, near Washington, D.C.
The critical issue at the moment is that nobody knows whether a tiny dose or a large dose of vaccine will be required to protect someone from the Ebola virus. The largest dose in these tests will be nearly 1,000 times greater than the smallest dose. Naturally, the smallest protective dose possible would be preferred because that much more vaccine can be distributed.
In November, vaccine trials will be expanded to include several hundred volunteers in Europe. Those tests will involve 250 doses of each of these two front-running vaccine candidates. Of course, there is no guarantee that either of these two vaccines will be effective, so it is good news that several other vaccines are in the pipeline. Three other vaccines are in earlier developmental stages at U.S. companies. In addition, three vaccines are being worked on in Russia.
It is important to note that an Ebola vaccine does not have to be 100% effective and all people at risk do not need to be vaccinated. Public health experts rely on the concept of ring vaccination. With ring vaccination, health officials predict where the disease is heading next, they then focus on immunizing people who will soon be in harm's way. This has the effect of placing a roadblock in Ebola's path.
Until quite recently, public health officials figured that a vaccine would not come along in time to be of any use in controlling the current Ebola outbreak. Now, amazingly, it looks like tens of thousands of doses of Ebola vaccine will be available starting in January 2015.
4. It should be pointed out that an Ebola vaccine will be used to prevent infection. A vaccine will do little to help people who are already infected with the virus. Currently, there is no FDA-approved drug to treat an Ebola infection. Treatment consists solely of supportive care, e.g., oxygen, intravenous fluids. It would be nice to have an anti-viral medication that would attack and kill the virus.
Favipiravir, is an experimental anti-viral drug being developed by Toyama Chemical of Japan with activity against many RNA viruses, including the Ebola virus. In a recent mouse study, if the mice were treated early on with favipiravir (day 6 after infection), the virus was rapidly cleared and the survival rate was 100%.
The team at the French National Institute of Health and Medical Research announced that it will conduct a test of favipiravir in Guinea in November. The team will administer the drug to about 50 patients in southern Guinea with initial results expected in January. If the team determines that the drug is promising, a larger-scale test will start after February to verify its safety and effectiveness.
5. On a lighter note, Dallas Emergency Services and Adoption Center has announced that Ebola patient Nina Pham's dog Bentley has tested negative for the deadly disease.
The Cavalier King Charles Spaniel was tested amid fears that he might have contracted Ebola from his owner, who was infected at the Dallas hospital where she cared for Thomas Eric Duncan, the only person to die of Ebola in the United States.
According to the Centers for Disease Control and Prevention, there have been no reports of dogs or cats becoming sick with Ebola or of being able to spread Ebola to people or other animals. However, some studies have shown that dogs may experience asymptomatic Ebola infections, meaning they may have the virus but do not get sick. It is not known whether these asymptomatic canines have the potential to transmit the Ebola virus to humans.