Ebola vaccine in Guinea shows promise

Some big news in the NY Times and elsewhere: according to a report published today in the British medical journal The Lancet: "An experimental Ebola vaccine being tested in the West African nation of Guinea during the outbreak of the viral disease has shown promising initial results...."

Of 7,651 individuals in the study group, 3,500 whom received the vaccination. The timing of the vaccination was randomly assigned, some immediately after being exposed directly or indirectly to the virus and some vaccinated after 21 days (the incubation period of the virus). After 10 days, none of those who received the vaccination came down with the disease, compared to 16 among those who did not receive the vaccination. This indicates that the vaccination is between 75% and 100% efficacious.

The "ring vaccination" approach is the same approach that was used to eradicate smallpox. The Ebola victim is "patient zero" and the people who came into contact with the patient, and the people who came into contact with those people, are the ring. According to the WHO, ring vaccination has two objectives: "(i) to test whether the vaccine protects people who have been in contact with an Ebola patient and (ii) to ensure that by vaccinating people in the “ring” a buffer zone — or protective ring — is created around “patient zero” to prevent the spread of infection."

Ebola hasn't been in the news much lately - here is a brief update on the Ebola situation in Guinea, Liberia, and Sierra Leone:




This figure from the Economist illustrates the magnitude of the Ebola outbreak in each country. Guinea had fewer infections than Sierra Leone and Libera, but a higher percentage of deaths per infection.

This figure from the same Economist article indicates that the outbreak has been largely contained:

This figure from Reuters using data from the WHO and World Bank shows how dramatically the Ebola outbreak has affected Guinea, Liberia, and Sierra Leone. Sierra Leone and Liberia, with the larger outbreaks, were hardest hit economically:

The Economist notes that "The inadequacies of the health-care systems in the three most-affected countries help to explain how the Ebola outbreak got this far. Spain spends over $3,000 per person at purchasing-power parity on health care; for Sierra Leone, the figure is just under $300." The vaccine will help, but these countries need to build stronger health-care systems. Unfortunately, many doctors and other health-care workers died in the fight against Ebola.

If you want to read some great blog posts about the Ebola outbreak, 3 of the 10 most popular Monkey Cage posts in 2014 related to Ebola. The posts were by Laura Seay and Kim Dionne.