Yellow Fever Vaccines

Authored by
Staff
Last reviewed
August 14, 2022

Yellow Fever Vaccines

Safe and effective yellow fever vaccines have been available for over 80 years. Yellow Fever vaccination is recommended by the U.S. CDC and World Health Organization (WHO) for people aged nine months or older and traveling to or living in areas at risk for the yellow fever virus, such as in regions of Africa and South America.

In addition, a WHO EYE strategy driven by PAHO in the Americas seeks to offer yellow fever vaccines to nearly one billion people by 2026.

The 17D yellow fever vaccine was approved for human use in 1938 and is still in use today, with about 850 million doses distributed worldwide, reported to the peer-review journal Nature.

Yellow Fever Vaccine Availability For 2022

As of August 14, 2022, yellow fever vaccines are available in the USA, AfricaAustralia, BarbadosBrazil, CaribbeanCanada, Chile, Costa Rica, the DRC, GermanyIndiaIndonesiaJamaica, Kenya, Northern IrelandMexicoPhilippines, ScotlandSingaporeVenezuela, and the U.K. 

The YF-VAX vaccine is available at U.S. travel vaccine-certified clinics and pharmacies, and the Stamaril vaccine remains available internationally.

Yellow Fever Vaccines - U.S. FDA Approved

YF-VAX Vaccine: YF-VAX is prepared by culturing the 17D-204 strain of yellow fever virus in living avian leukosis virus-free chicken embryos. The vaccine contains sorbitol and gelatin as a stabilizer, lyophilized, and hermetically sealed under nitrogen. No preservative is added. YF-Vax is licensed in the USA and is available in 2021. STN:  BL 103915

Stamaril Vaccine: Stamaril is a live, attenuated yellow fever vaccine containing the active Yellow fever virus 17D-204 strain produced in specified pathogen-free chick embryos. Stamaril has been offered in Europe and other countries for decades. Stamaril yellow fever vaccine is currently distributed in over 70 countries. However, it is considered investigational in the U.S.

Note: Yellow fever vaccines provide effective immunity in about ten days for 80-100% of people vaccinated, and within 30 days, more than 99% of people vaccinated, says the WHO.

Yellow Fever Vaccine Candidates

RegaVax is a vector vaccine candidate that uses the yellow fever vaccine virus's genetic code as a carrier (or vector) for the coronavirus spikes' genetic code. RegaVax is a platform technology to design and produce live-attenuated recombinant vaccines vectored by the original yellow fever vaccine (YF17D).

Najít Technologies HydroVax-002 YFV is a Novel Inactivated Yellow Fever vaccine candidate conducting phase 1 clinical research with the NIH, evaluating dosages of 1 mcg and five mcg was given intramuscularly on Day 1 and Day 29.

Yellow Fever Vaccination Requirements

In the USA, vaccinated people should receive a yellow fever card called the International Certificate of Vaccination and Prophylaxis to prove they recently had a yellow fever vaccine. A standardized pre-vaccination checklist for 2022 is posted to ensure the yellow fever vaccine is indicated for the destination and identify potential vaccine contraindications. Where a certificate is not required for entry into a country, this does not necessarily mean there is no risk of disease, and the yellow fever vaccine might still be recommended. 

As of August 6, 2022, an interactive world map showing travel recommendations by destination and yellow fever vaccination requirements for specific countries is available on the CDC Travelers' Health webpage. Forty-seven countries in Africa (34) and Central and South America (13) are either endemic or have yellow fever endemic regions, reported the WHO on March 25, 2022.

Yellow Fever Vaccine Fractional Dosage

The peer-review journal The Lancet published results from a clinical study in January 2021 (updated Feb. 2022) that concluded, 'Fractional doses of all WHO-prequalified yellow fever vaccines were non-inferior to the standard dose in inducing seroconversion 28 days after vaccination, with no major safety concerns. These results support the use of fractional dosage in the general adult population for outbreak response in situations of a vaccine shortage.'

The current WHO position on the use of fractional yellow fever vaccine was set out in the 2013 WHO position paper.

Yellow Fever Monoclonal Antibody Treatment

The TY014 treatment candidate is directed against the envelope protein on the surface of the Yellow Fever virus and prevents viral replication by limiting viral fusion to host cells. Tysana Pte Ltd is currently conducting a phase 1 study on humans.

Yellow Fever Travel Advisories

The U.S. CDC recently issued yellow fever Travel Advisories for GhanaNigeria, and Brazil. Since September 2021, nine countries in the WHO African Region (Cameroon, Chad, Central African Republic, Côte d'Ivoire, the Democratic Republic of Congo, Ghana, Niger, Nigeria, and the Republic of Congo) have reported human laboratory-confirmed cases of yellow fever. And proof of yellow fever vaccination is required to visit areas in Argentina, AngolaBoliviaBrazil, Ghana, Kenya, Paraguay, Rwanda, and Uganda.

The CDC has recently issued travel advisories regarding yellow fever outbreaks in Nigeria and Kenya.

Yellow Fever Vaccine News For 2008 - 2022

August 5, 2022 - The U.S. Embassy in Nairobi, Kenya, published a Health Alert for U.S. Citizens regarding Yellow Fever outbreaks in Isiolo and Garissa Counties.

August 5, 2022 - The Republic of the Congo launched a preventive mass vaccination campaign that aims to vaccinate more than 93% of the (4 million) population against yellow fever.

July 30, 2022 - The peer-review journal Vaccine published: Previous biological therapy and impairment of the IFN-γ/IL-10 axis are associated with a low immune response to 17DD-YF vaccination in patients with spondyloarthritis (SpA). The use of biologic disease-modifying antirheumatic drugs lowered immune responsiveness to 17DD-YF vaccination for yellow fever in patients with spondyloarthritis. Therefore, the inflammatory status prior to vaccination and impairment of the IFN-γ/IL-10 axis at the peak of viremia may determine the immunogenicity of the 17DD-YF vaccination in patients with SpA.

July 27, 2022 - The U.S. CDC issued an Alert - Level 2, Practice Enhanced Precautions, regarding a yellow fever outbreak in Kenya.

July 21, 2022 - Gavi published: Routine vaccines, extraordinary impact: Yellow fever.

July 21, 2022 - The Times of India reported an under-immunized 26-year-old person who recently traveled from Brazil to Bengaluru, India, was taken to a government quarantine facility after it was discovered that he hadn't taken the Yellow Fever vaccine before heading to India.

July 11, 2022 - In a non-peer-reviewed study, researchers in Europe performed an open-label, non-randomized clinical trial studying the safety and immunogenicity following concurrent delivery of the Yellow fever virus (YFV) vaccine with Tick-borne encephalitis virus (TBEV) and Japanese encephalitis virus (JE) virus vaccines. Conclusions: Inactivated TBEV or JEV vaccines can be coadministered with the live attenuated YFV vaccine without an increased risk of adverse events and without reduced development of nAbs to the respective viruses.

June 14, 2022 - The WHO stated - Donors making a difference: Eliminating neglected tropical diseases (yellow fever) and other outbreaks.

May 26, 2022 - The PAHO reported cases of yellow fever had been reported in three countries in the South America Region during 2022: Bolivia (5), Brazil (3), and Peru (2). Similarly, PAHO/WHO recommends that the Member States have yellow fever vaccine reserve stockpiles, depending on the availability of vaccines in the country, which will allow for responding to potential outbreaks.

May 4, 2022 - The U.S. CDC issued an Alert - Level 2, Practice Enhanced Precautions, regarding a yellow fever outbreak in Nigeria. Furthermore, the December 2021 Alert for Yellow Fever in Ghana continues to be in effect.

April 25, 2022 - The WHO reported seven suspected cases in Uganda that tested positive for yellow fever antibodies by plaque reduction neutralization test. 

April 13, 2022 - Tocantins State Health Department reported a recent yellow fever death, an unvaccinated tourist in the southern Brazilian state. Since 2018, Tocantins has not recorded cases of Yellow Fever in humans.

April 7, 2022 - Emergex Vaccines Holding Limited announced an agreement with ATCC to progress the preclinical development of its T-Cell Yellow Fever booster vaccine candidate.

March 25, 2022 - The WHO reported 53 suspected yellow fever cases, including six deaths in the Republic of Kenya in early 2022. Kenya's last reported yellow fever outbreak was in 2011. Furthermore, the WHO-UNICEF estimated coverage through routine yellow fever immunization is 7% of the target population in the central area of Kenya. The WHO assesses the public health risk as high at Kenya's national and regional levels.

March 18, 2022 - Rwanda's Ministry of Health announced all residents and visitors traveling to yellow fever endemic countries should be vaccinated at least ten days before traveling.

March 14, 2022 - The U.K. reported Kenya's Ministry of Health confirmed a yellow fever outbreak in Isiolo County. The first case was detected on 12 January 2022, and as of 5 March 2022, 15 cases, with three deaths, are reported.

March 13, 2022 - The WHO Africa reported eight villages in three Kenya sub-counties had been affected. Detecting yellow fever cases is concerning as Kenya has negligible population immunity in the districts reporting confirmed cases. In addition, the overall national immunity is thus far below the threshold necessary to provide herd immunity.

March 8, 2022 - BMC Public Health published new research: Changing epidemiology of yellow fever virus in Oyo State, Nigeria. While the Eliminating Yellow fever Epidemic strategy was launched in Nigeria in April 2018, substandard vaccination coverage continues to be a cause for concern.

February 11, 2022 - Paraguay's authorities confirmed proof that yellow fever vaccination is required for travelers arriving from or leaving Bolivia, Brazil, Peru, and Venezuela.

January 22, 2022 - The Costa Rica Ministry of Health confirmed the Yellow Fever vaccine will not be available until late February 2022.

December 13, 2021 - The U.S. CDC issued a Level 2 Travel Advisory for Ghana's ongoing yellow fever outbreak.

December 1, 2021 - The WHO reported from 15 October to 27 November 2021, there were 202 suspected cases of Yellow Fever, including 70 confirmed cases and 35 deaths [Case Fatality Ratio: 17%] reported in four regions in Ghana (Savannah, Upper West, Bono and Oti regions) in Africa.

November 16, 2021 - The U.K. published a pre-vaccination checklist to ensure the yellow fever vaccine is indicated for the intended travel destination and enable vaccinators to identify existing contraindications or precautions.

November 8, 2021 - Change in vaccination strategy averted outbreak of urban yellow fever in São Paulo, Brazil, scientists say.

November 8, 2021 - The WHO Africa reported technical officers in the National Public Health Laboratory had increased testing capacity in South Sudan to control yellow fever outbreaks.

November 5, 2021 - Local media reported residents of Belo Horizonte who plan to visit the parks in the capital of Minas Gerais, located in southwest Brazil, are required a yellow fever vaccination. The rule began to be applied in 15 other places.

October 13, 2021 - The WHO confirmed the IHR National Focal Point for Venezuela reported seven confirmed human cases of yellow fever.

September 30, 2021 - The government of Nigeria requires that all travelers nine months of age or older show proof of yellow fever vaccination to enter the country.

September 12, 2021 - People in Taiwan can get inoculated against yellow fever for free through November 2021.

June 30, 2021 - The U.S. CDC issued a Level 2 Travel Alert regarding an outbreak of yellow fever in Nigeria.

April 5, 2021 - Sanofi Pasteur announced that YF-VAX is once again available in the USA. Providers with a current Yellow Fever Vaccination Stamp may now order YF-VAX vaccines.

March 9, 2021 - The Canadian Committee to Advise on Tropical Medicine and Travel (CATMAT) issued a statement confirming fractional dosing is no longer valid as the shortage of Yellow Fever vaccine has been lifted.

March 7, 2021 - In a recent paper, researchers were able to quantify preventive mass vaccination campaigns (PMVC) to reduce yellow fever outbreaks at the province level using the self-controlled case series method. PMVCs in Africa averted an estimated 22% to 45% of outbreaks during this study period.

March 1, 2021 - There is an outbreak of yellow fever in Nigeria, first reported in November 2020, said the U.S. CDC. The outbreak is currently in Bauchi, Benue, Delta, Ebonyi, and Enugu states. Unless vaccinated, travelers should not visit these areas.

February 18, 2021 - PLOS published a new study: Assessing the impact of preventive mass vaccination campaigns on yellow fever outbreaks in Africa.

January 8, 2021 - Published in The Lancet: clinical trial results found that giving a person one-fifth of the standard yellow fever vaccine dose effectively and safely will make it easier for governments and international organizations to prevent people from getting sick from yellow fever during outbreaks of a vaccine shortage.

December 23, 2020 - Sanofi announced, 'To help meet U.S. needs, the yellow fever vaccination with STAMARIL will continue to be available into 2021.'

December 23, 2020 - The WHO announced between 6 November and 15 December 2020, 52 suspected cases of yellow fever, including 14 deaths, were reported in Guinea.

December 11, 2020 - The WHO reported Ethiopia conducted a reactive yellow fever vaccination campaign to protect communities around an affected district. A yellow fever vaccination campaign targeting 700 000 people in Southern Nations, Nationalities and Peoples (SNNP), and Oromia regions was conducted in November 2020, achieving 93% of the target.

December 3, 2020 - The K.U. Leuven research institution in The Netherlands announced their partnership on developing a vector-based COVID-19 vaccine candidate.

November 30, 2020 - The U.S. CDC issued a Level 2 Travel Alert, which stated, 'the Nigeria Centre for Disease Control (NCDC) is reporting yellow fever outbreaks in multiple states (Bauchi, Benue, Delta, Ebonyi, and Enugu).

November 2, 2020 - The Nigeria Centre for Disease Control - preliminary report for Delta State on November 5, 2020, notified 48 suspected yellow fever cases (Y.F.) with 30 deaths (CFR 62.5%). The Y.F. vaccination status of most of the suspected cases is unknown.

October 26, 2020 - Despite the COVID-19 pandemic, the South Sudan Ministry of Health, with support from Eliminate Yellow Fever Epidemics partners including Gavi, the Vaccine Alliance, WHO, UNICEF, and others, launched a reactive yellow fever vaccination campaign in Kajo, Keji, Central Equatoria State. The campaign aims to protect over 90,000 individuals aged nine months to 60 years from yellow fever infection.

August 1, 2020 - The WHO stated Yellow fever is endemic in French Guiana.

July 17, 2022 - Original Research: Planned Yellow Fever Primary Vaccination Is Safe and Immunogenic in Patients With Autoimmune Diseases: A Prospective Non-interventional Study.

June 25, 2020 - Sanofi Pasteur, the manufacturer of the only yellow fever vaccine (YF-Vax) licensed in the United States, has announced a total depletion of YF-Vax as they transition to a new production facility. They are reassessing the timing of YF-Vax's return to supply and expect to provide an update in December 2020.

April 2020 - Sanofi Pasteur's new U.S. YF-VAX® (Yellow Fever Vaccine) production facility has been licensed by the U.S. FDA and doses continue progressing through manufacturing. In the U.S., Sanofi Pasteur has worked with the FDA to provide access to another yellow fever vaccine through this EAP. Manufactured by Sanofi Pasteur in France, this vaccine, STAMARIL® (Yellow Fever Vaccine [Live]), is registered and distributed in more than 70 countries.

September 30, 2019 - Oregon Health & Science University spinoff Najít Technologies, Inc., of Beaverton, Oregon, will test a yellow fever version of the HydroVax vaccine platform licensed by OHSU. A $3.1-million grant from the National Institutes of Health to Najít will enable Duke University to lead the Phase 1 human clinical trial. In addition, OHSU will study how trial participants' immune systems respond to the yellow fever vaccine. July 19, 2019 - A Randomized Phase I Clinical Trial of HydroVax-YFV, a Novel Inactivated Yellow Fever Vaccine.

August 1, 2019, a study published by the NEJM concluded: 'A fractional dose of the 17DD yellow fever vaccine effectively induced seroconversion in seronegative participants at baseline. In addition, titers remained above the threshold for seropositivity at 1-year after vaccination in nearly all seropositive participants at 1-month after vaccination. These findings support the use of fractional-dose vaccination for outbreak control.'

Yellow Fever Diagnosis

Yellow fever is difficult to diagnose, especially during the early stages. Polymerase chain reaction testing in blood and urine can sometimes detect the virus in the early stages of the disease. However, in later stages, testing to identify antibodies is needed. The U.S. CDC publishes a list of frequently asked questions and answers found on this CDC webpage. And the WHO's FAQ list is found on this webpage.

Note: The content on this webpage has been aggregated from the WHO, the U.S. CDC, and research studies reviewed by healthcare providers, such as Dr. Robert Carlson.