Yellow fever is a disease caused by a virus transmitted by mosquitos from the Aedes family, particularly Aedes Aegypti. In the first few days yellow fever is hard to recognize because it is a disease that has symptoms common to many viral diseases: fever, headache, muscle aches, etc. But then after the first phase, you enter the real “yellow” fever phase, because patients have fever but also jaundice. Sometimes, at the end of the disease (people) can haemorrhage (bleed), and this is why it is very important for suspected yellow fever (patients) to go and seek treatment. There is no specific treatment, but good clinical management can help people recover from this disease and not die from it. The first few cases were detected in December (2015), but then around end of January there were many cases. The problem is that there are cases in the capital city and it is always very difficult to deal with an outbreak within a capital city because of the density of the population, but also the density of the mosquitoes because yellow fever is transmitted by mosquitoes. There is a very good vaccine for yellow fever. This vaccine is safe, because the number of adverse effects following vaccination is really negligible. The good news is also that this vaccine protects for a very long period of time, probably one’s entire life, and this is why it’s the mainstay of the response for yellow fever is really to vaccinate people. WHO has a global emergency stockpile for yellow fever that is used to help countries face outbreaks of yellow fever. This emergency yellow fever vaccine stockpile is composed of six million doses, but the problem was that the Angola outbreak is in the big city with more than six million people. So we had to use immediately the entire stockpile. Now the stockpile has been replenished and we are sending more vaccine to finish the vaccination. Yes and no. “Yes” because as with any outbreak, there is risk of amplification, and also the outbreak can go to other countries and produce problems in other regions. “No” because fortunately, we do have a vaccine. The vaccine is safe, the vaccine is effective and we can control the outbreak. What is very important is that people travelling to yellow fever endemic countries need to get vaccinated. It’s one of the recommendations under the International Health Regulations but unfortunately many people are still not vaccinated. Everybody has to get vaccinated against yellow fever, if they are travelling to yellow fever endemic countries, and WHO has a list of the countries that are endemic, people should look at our website to know before they travel what the risk is. Also, this disease is transmitted by mosquitoes, the same mosquitoes that transmit dengue, Zika, chikungunya, when people are travelling to countries where those mosquitoes are present, (they) should protect themselves against mosquito bites.