# Yellow fever

Yellow fever is a potentially fatal tropical disease caused by a virus that is transmitted to humans through the bite of infected mosquitoes. Illness ranges in severity from an influenza-like syndrome to severe hepatitis and hemorrhagic fever. Yellow fever can be prevented by vaccination. Travellers to areas with yellow fever transmission should take precautions against exposure to mosquitoes.
* This is an article about health issues. While contributors do their best, we cannot take account of your individual health needs. Consult your doctor for individual medical advice.

## Understand

Countries where yellow fever is endemic - with CDC vaccination recommendation (may be abbreviated) as of 2017 in brackets - are below. "High-risk" travellers are a small fraction of travellers whose travel plans or lifestyle expose them to more mosquito bites than average.
Africa
| Country | Traveller's Age | Additional Comments |
| Angola | over 9 mo. | |
| Benin | over 9 mo. | |
| Burkina Faso | over 9 mo. | |
| Burundi | over 9 mo. | |
| Cameroon | over 9 mo. | |
| Central African Republic | over 9 mo. | |
| Chad | over 9 mo. | going to areas south of the Sahara |
| Congo: Democratic Republic of the Congo | over 9 mo. | |
| Congo: Republic of the Congo | over 9 mo. | |
| Côte d'Ivoire | over 9 mo. | |
| Equatorial Guinea | over 9 mo. | |
| Eritrea | | only high-risk travellers in certain areas |
| Ethiopia | over 9 mo. | not recommended for travellers who are not high-risk whose itinerary is limited to Afar and Somali provinces |
| Gabon | over 9 mo. | |
| The Gambia | over 9 mo. | |
| Ghana | over 9 mo. | |
| Guinea | over 9 mo. | |
| Guinea-Bissau | over 9 mo. | |
| Kenya | over 9 mo. | cities of Nairobi and Mombasa and certain other areas have lower risk of transmission |
| Liberia | over 9 mo. | |
| Mali | over 9 mo. | going to areas south of the Sahara |
| Mauritania | over 9 mo. | going to areas south of the Sahara |
| Niger | over 9 mo. | going to areas south of the Sahara |
| Nigeria | over 9 mo. | |
| Rwanda | | only for high-risk travellers |
| Sao Tome and Principe | | only for high-risk travellers |
| Senegal | over 9 mo. | |
| Sierra Leone | over 9 mo. | |
| Somalia | | only for high-risk travellers and only in certain regions |
| South Sudan | over 9 mo. | |
| Sudan | over 9 mo. | going to areas south of the Sahara outside of Khartoum |
| Tanzania | over 9 mo. | only for high-risk travellers |
| Togo | over 9 mo. | |
| Uganda | over 9 mo. | |
Central America & South America
| Country | Traveller's Age | Additional Comments |
| Argentina | over 9 mo. | going to Corrientes and Misiones province, including Iguazú Falls. Recommended for high-risk travellers going to Formosa province and parts of Chaco, Jujuy, and Salta provinces. |
| Bolivia | over 9 mo. | travelling to certain areas below 2300m that are east of the Andes |
| Brazil | over 9 mo. | going to the endemic zone, which does not include Rio de Janeiro or São Paulo |
| Colombia | over 9 mo. | Not recommended if your itinerary is limited to Bogotá and San Andrés y Providencia department. If your trip is limited to these places and Barranquilla, Cali, Cartagena, and Medellín, the risk is lower and vaccines are only recommended for high-risk travellers |
| Ecuador | over 9 mo. | who are travelling to certain areas east of the Andes Mountains or for high-risk travellers in certain areas west of the Andes |
| French Guiana | over 9 mo. | |
| Guyana | over 9 mo. | |
| Panama | over 9 mo. | travelling east of the canal zone |
| Paraguay | over 9 mo. | outside of Asunción |
| Peru | over 9 mo. | travelling to many areas, especially east of the Andes Mountains; not recommended for travellers whose itinerary is limited to Lima, Cusco, Machu Picchu, the Inca Trail, and areas above 2300 meters. |
| Suriname | over 9 mo. | |
| Trinidad and Tobago | over 9 mo. | only if going to dense forests on Trinidad |
| Venezuela | over 9 mo. | except if only travelling to certain parts of the northern coastal area |

## Vaccination

A vaccine is available which provides immunity for at least ten years. Many countries will require that you be vaccinated against yellow fever if you are coming from a country where it is present or have been in such a country within the last 6 days (the incubation period). If this is the case you will need to present a "World Health Organization International Certificate of Vaccination" with an appropriately dated certification on the "International Certificate of Vaccination or Revaccination Against Yellow Fever" page to immigration officials. This little yellow booklet will be given to you when you are vaccinated against yellow fever for the first time, which is valid for life. Carry it with your passport: you'll typically present them to immigration officials at the same time.
It is generally easiest to get a yellow fever vaccination in your home country before you leave on your trip. The vaccination is not in the normal vaccination schedules of many countries outside the infected areas since it is unnecessary unless you are travelling and has a somewhat higher risk of complications than many other vaccines. You will need to especially request a yellow fever vaccination from a designated yellow fever vaccination center. Immunity is considered to start 10 days from the time of the vaccination, so be sure to get vaccinated 10 days before you enter an infected country. The vaccine is live and not entirely inactive: many people have mild flu-like symptoms for a couple of days after receiving this vaccine, so it would be good not to be planning anything strenuous in those days.
Depending on how the vaccine is cultivated, you may need to allow about half an hour for a yellow fever vaccination as you will be observed for an allergic reaction after it is administered.

## Vaccination requirements

Some countries have mandatory yellow fever vaccination requirements. The exact requirements vary from country to country and may also vary from time to time. The following is a list of countries and territories which had yellow fever vaccination requirements as of 2017 according to the CDC. Countries requiring proof of vaccination upon arrival from all other countries (as opposed to only upon arrival from endemic countries) for all travellers more than one year old are marked below.
Among countries that require it upon arrival from endemic zones, some exclude a few individual countries or regions from this requirement, so look up the details for your specific destination or destinations. Some even require the vaccine if you change planes in an endemic country, even if you don't leave the airport. Others don't count airport layovers, or only care about them if they are longer than a certain number of hours.
| Country | Proof of Vaccination |
| Afghanistan | from endemic zones |
| Albania | from endemic zones |
| Algeria | from endemic zones |
| Angola | always |
| Antigua and Barbuda | from endemic zones |
| Australia | from endemic zones |
| Bahamas | from endemic zones |
| Bahrain | from endemic zones |
| Bangladesh | from endemic zones |
| Barbados | from endemic zones |
| Belize | from endemic zones |
| Benin | from endemic zones |
| Bhutan | from endemic zones |
| Bolivia | from endemic zones |
| Bonaire | from endemic zones |
| Botswana | from endemic zones |
| Brazil | from Angola and the Democratic Republic of the Congo |
| Brunei | from endemic zones |
| Burkina Faso | from endemic zones |
| Burundi | always |
| Cambodia | from endemic zones |
| Cameroon | from endemic zones |
| Cape Verde | from endemic zones |
| Central African Republic | always |
| Chad | from endemic zones |
| China | from endemic zones (no requirement for entering Hong Kong or Macau |
| Christmas Island | from endemic zones |
| Cocos Islands | from endemic zones |
| Colombia | from endemic zones |
| Democratic Republic of the Congo | always |
| Republic of the Congo | always |
| Cote d'Ivoire | always |
| Costa Rica | from endemic zones |
| Cuba | from endemic zones |
| Curaçao | from endemic zones |
| Djibouti | from endemic zones |
| Dominica | from endemic zones |
| East Timor | from endemic zones |
| Egypt | from endemic zones |
| El Salvador | from endemic zones |
| Equatorial Guinea | from endemic zones |
| Eritrea | from endemic zones |
| Eswatini | from endemic zones |
| Ethiopia | from endemic zones |
| Fiji | from endemic zones |
| French Guiana | always |
| French Polynesia | from endemic zones |
| Gabon | always |
| Gambia | from endemic zones |
| Ghana | always |
| Grenada | from endemic zones |
| Guadeloupe | from endemic zones |
| Guatemala | from endemic zones |
| Guinea | from endemic zones |
| Guinea-Bissau | always |
| Guyana | from endemic zones |
| Haiti | from endemic zones |
| Honduras | from endemic zones |
| India | from endemic zones |
| Indonesia | from endemic zones |
| Iran | from endemic zones |
| Iraq | from endemic zones |
| Jamaica | from endemic zones |
| Jordan | from endemic zones |
| Kazakhstan | from endemic zones |
| Kenya | from endemic zones |
| Kiribati | from endemic zones |
| Kyrgyzstan | from endemic zones |
| Laos | from endemic zones |
| Lesotho | from endemic zones |
| Liberia | always |
| Libya | from endemic zones |
| Madagascar | from endemic zones |
| Malawi | from endemic zones |
| Malaysia | from endemic zones |
| Maldives | from endemic zones |
| Mali | always |
| Malta | from endemic zones |
| Martinique | from endemic zones |
| Mauritania | from endemic zones |
| Mauritius | from endemic zones |
| Mayotte | from endemic zones |
| Montserrat | from endemic zones |
| Mozambique | from endemic zones |
| Myanmar | from endemic zones |
| Namibia | from endemic zones |
| Nauru | from endemic zones |
| Nepal | from endemic zones |
| Netherlands Antilles | from endemic zones |
| New Caledonia | from endemic zones |
| Niger | always |
| Nigeria | from endemic zones |
| Niue | from endemic zones |
| Norfolk Island | from endemic zones |
| North Korea | from endemic zones |
| Oman | from endemic zones |
| Pakistan | from endemic zones |
| Panama | from endemic zones |
| Paraguay | from endemic zones |
| Philippines | from endemic zones |
| Pitcairn Islands | from endemic zones |
| Reunion | from endemic zones |
| Rwanda | from endemic zones |
| Saba | from endemic zones |
| Saint Barthelemy | from endemic zones |
| Saint Helena (island) | from endemic zones |
| Saint Kitts and Nevis | from endemic zones |
| Saint Lucia | from endemic zones |
| Saint Martin | from endemic zones |
| Saint Vincent and the Grenadines | from endemic zones |
| Samoa | from endemic zones |
| Sao Tome and Principe | from endemic zones |
| Saudi Arabia | from endemic zones |
| Senegal | from endemic zones |
| Seychelles | from endemic zones |
| Sierra Leone | always |
| Singapore | from endemic zones |
| Sint Eustatius | from endemic zones |
| Solomon Islands | from endemic zones |
| Somalia | from endemic zones |
| South Africa | from endemic zones |
| Sri Lanka | from endemic zones |
| Sudan | from endemic zones |
| Suriname | always |
| Tanzania | from endemic zones |
| Thailand | from endemic zones |
| Togo | always |
| Trinidad and Tobago | from endemic zones |
| Uganda | from endemic zones |
| Venezuela | from Brazil |
| Vietnam | from endemic zones |
| Zambia | from endemic zones |
| Zimbabwe | from endemic zones |