Vaccine Certificates Can Curtail Yellow Fever Outbreaks

Since 1970, yellow fever has re-emerged as a public health threat in the Region of the Americas, and the risk of yellow fever outbreaks remains high in 2024.

This mosquito-transmitted, acute viral hemorrhagic disease has become endemic in 13 countries in Central and South America.

It is a substantial health risk to about 32 million visitors to South America this year.

On September 19, 2024, the Pan American Health Organization (PAHO) reported five countries in the Americas had confirmed 38 yellow fever cases, 19 of which were fatal.

Peru is the hardest-hit country, with 18 cases and nine deaths confirmed in various departments this year.

These yellow fever cases were all males between 18 and 83 years of age and had a history of exposure to wild and/or wooded areas due to agricultural work activities.

Unfortunately, these men had no yellow fever vaccination records.

Additionally, the PAHO reported that Bolivia, Brazil (3 cases, two deaths), Colombia, and Guyana are the other South American countries reporting cases in 2024.

Although immunization is one of the most successful public health interventions to prevent this disease, most cases reported during 2024 do not have a history of yellow fever vaccination.

Yellow fever has a unique status in the International Health Regulations (2005), which outline requirements for proof of vaccination for people who travel to specific countries or enter some countries from an area where yellow fever is endemic.

To prevent the importation of disease, many countries require proof of vaccination against yellow fever before issuing a visa, mainly if travelers come from or have visited yellow fever-endemic areas.

The U.S. CDC lists South American countries that are endemic to yellow fever.

The PAHO says countries must guarantee vaccination coverage greater than or equal to 95% in the populations of at-risk areas. Health authorities should ensure that they have a strategic reserve inventory that allows them to maintain routine vaccination and, at the same time, respond to possible outbreaks.

In 2023, over 60 million individuals received vaccinations under the WHO's Eliminate Yellow Fever Epidemics strategy.

The U.S. CDC says Sanofi Pasteur's YF-VAX® vaccine is safe and highly effective and is recommended for most travelers aged nine months and older.

Vaccination provides effective immunity within 30 days for 99% of those vaccinated. A single dose can confer sustained immunity and life-long protection without a booster.

"The CDC also recommends that travelers heading to regions experiencing yellow fever outbreaks should consider receiving a booster dose if it has been over ten years since their last vaccination," says Duellyn Pandis, DNP, MS, APRN, FNP-C, Certificate in Travel Health®.

"Certain people should not receive the vaccine, and waivers can be provided," added Pandis, President & CEO of Passport Health-Tampa. "To determine what is best for you, schedule an appointment 4-6 weeks before departure."

YF-Vax is only offered at certified travel vaccine clinics and pharmacies in the U.S.