Vaccine News

The World Health Organization (WHO) today published the 51st situation report for the multi-country outbreak of mpox, including an update on the epidemiological situation for mpox in Africa, with data as of late April 2025.

This year, the WHO has confirmed 137,892 mpox cases,  317 related fatalities, from 132 reporting countries. 

The WHO stated on April 29, 2025, 'Wherever mpox outbreaks are not quickly contained and human-to-human transmission is not stopped, they continue to represent a potential risk of sustained transmission in the community.'

Highlights from this report include, but are not limited to, the following:

Cases of mpox due to clade Ib monkeypox virus (MPXV) continue to be reported primarily in Africa, where eleven countries have reported community transmission of this strain in the past six weeks, as person-to-person transmission has occurred through various means during this outbreak.'

Currently, Uganda is reporting the highest number of confirmed mpox cases globally, with 200 to 300 new cases reported per week. To date, the country has detected only clade Ib MPXV.

The Democratic Republic of the Congo (DRC) continues to report the highest number of cumulative confirmed mpox cases in Africa in 2025, despite a decrease in the number of confirmed cases reported in recent weeks, likely due to a reduction in testing and confirmation capacity. Clades Ia and Ib MPXV continue to circulate in the DRC.

This report provides an overview of mpox vaccination in countries in the African Region, where to date more than 662,000 doses of Bavarian Nordic's JYNNEOS® (MVA-BN®) vaccines have been administered in seven countries.

From the total number of doses, 88% have been administered in the DRC, where the vaccination strategy is being revised in light of the limited vaccine supply.

In the United States, there is an ample supply of the JYNNEOS vaccine, which is recommended by the U.S. CDC for specific individuals when visiting mpox outbreaks in 2025. This mpox vaccine is commercially available in the U.S. at clinics and pharmacies.

The ongoing chikungunya epidemic in France's Réunion Department has resulted in 39,532 cases and nine associated deaths since the beginning of 2025.

This includes 4,304 new cases from April 7 to April 13, 2025.

On April 23, 2025, ARS Réunion stated that 'the chikungunya epidemic continues across the island. Although the number of chikungunya-related primary care consultations is stabilizing, the number of emergency room visits is increasing.'

Local health authorities, the World Health Organization, and the U.S. Centers for Disease Control and Prevention (CDC) are urging heightened vigilance for travelers to Réunion.

Visitors are advised to take preventive measures against mosquito bites, such as using insect repellent, wearing long-sleeved clothing, and staying in accommodations with screened windows or air conditioning.

Additionally, international travelers may pose a risk of introducing chikungunya to other regions where Aedes mosquito vectors are present. It is recommended that they monitor for symptoms, such as fever, joint pain, and rash, for up to two weeks and seek medical attention if symptoms arise.

The CDC says if you are pregnant, consider reconsidering travel to the affected states, especially if you are nearing the delivery of your baby. Mothers infected around the time of delivery can pass the virus to their baby before or during delivery.

Newborns infected in this way or by a mosquito bite are at risk for severe illness, including poor long-term outcomes.

The vaccination campaign, which started on April 7, 2025, is available for individuals aged 18 to 64 with comorbidities. Health authorities emphasize the importance of monitoring for allergic reactions within 72 hours of vaccination and seeking immediate medical attention if any symptoms occur.

The CDC's Level 2 Travel Advisory recommends vaccination against chikungunya for adults traveling to a destination with a current chikungunya outbreak. The vaccine should not be administered to individuals with weakened immune systems or those who have experienced a severe allergic reaction to any component of the vaccine.

In the United States, chikungunya vaccination services are available as of April 30, 2025, at travel clinics and pharmacies.

The Yellow fever outbreak in South America now includes the Republic of Ecuador, home to approximately 17 million residents.

As of April 28, 2025, Ecuador's Public Health Minister, Edgar Lama, announced that there are three confirmed cases, with a fourth case under investigation.

The first case was detected in the province of Zamora Chinchipe, located at the southeastern end of the Amazon Basin. 

Furthermore, Minister Lama stated in a media release, "We remain vigilant and are not in any situation similar to Colombia and Peru, which have had so many cases of yellow fever," he stated.

As of the end of April 2025, yellow fever outbreaks have been reported throughout South America.

Ecuador is a popular tourist destination that features the Galápagos Islands in the Pacific Ocean.

To alert international travelers to the Yellow fever health risk, the U.S. CDC states that proof of vaccination is not required for direct travel from the United States, or when traveling to areas above 7,550 ft in elevation, or the cities of Guayaquil or Quito, or the Galápagos Islands.

However, the CDC has included Ecuador in recent Dengue and Oropouche in Level 1 Travel Health Advisories.

In the United States, yellow fever vaccination appointments are offered at certified travel clinics and pharmacies.

While most hikers and campers await the results of a Phase 3 clinical trial of the most advanced Lyme disease vaccine candidate, The Lancet Infectious Diseases recently published an article highlighting very positive data from the Phase 2 study.

On April 25, 2025, results from the NCT04801420 study confirm the previously observed safety and immunogenicity profiles of VLA15 in adults and extend them to children aged five years and older, as well as adolescents.

Additionally, the greater immunogenicity of VLA15 among children and adolescents might translate to increased flexibility in the real-world clinical setting.

According to Vaneva SE and Pfizer Inc., VLA15 is an investigational multivalent protein subunit vaccine that utilizes an established mechanism of action for a Lyme disease vaccine, targeting the outer surface protein A (OspA) of Borrelia burgdorferi, the bacterium that causes Lyme disease.

OspA is a surface protein expressed by the bacteria when present in a tick. Blocking OspA inhibits the bacterium’s ability to leave the tick and infect humans.

The vaccine candidate covers the six most prevalent OspA serotypes expressed by the Borrelia burgdorferi sensu lato species in North America and Europe.

Lyme disease, if left untreated, can cause serious chronic complications affecting the skin, joints, heart, or nervous system. 

According to various health agencies, the medical need for vaccination against Lyme disease is steadily increasing as the geographic footprint of the disease widens in the United States and Europe.

Throughout Europe, the bacteria are only transmitted by the bites of the ticks Ixodes ricinus and I. persulcatus. In the most affected regions, tick infection rates may exceed 10%. These areas are primarily located in central Europe.

However, the ECDC says in recent years, the spread of infected ticks has extended toward northern latitudes, including Scandinavia.

In the United Kingdom, the South of England and the Scottish Highlands have been earmarked by the government as high-risk areas for Lyme disease in 2025. Annually, the UK Health Security Agency reports about 1,500 laboratory-confirmed cases of Lyme disease.

With millions of people returning to the woods and mountains this summer, analysts say there is significant pent-up demand for an effective Lyme disease vaccine.

Once again, research affirms that healthcare professionals remain the most trusted source of information (73%) and can significantly influence disease prevention efforts, such as vaccination.

A University of Texas Southwestern Medical Center survey published on April 24, 2025, found that 58% of adults say they would be willing to be vaccinated against mpox if their healthcare provider recommended it.

This data represents a 12% increase since 2022.

According to an article published in Vaccine (Volume 56, May 22, 2025, 127141), self-reported knowledge of mpox (40%), as well as perceived self-efficacy (55%) and mean risk perception (3.2), have also increased since the 2022 survey.

Respondents from the Health and Human Services Region 1 (CT, ME, MA, NH, RI, VT) were the least likely to receive the vaccine, even when recommended to do so.

These results highlight the need for ongoing education among adults to improve awareness of and vaccination intention for the mpox vaccine.

The consistently high degrees of trust placed in healthcare professionals and officials should guide future communications about mpox and other infectious diseases, and reinforce the importance of leveraging trusted sources to share essential public health information, wrote these researchers.

In May 2022, an unprecedented global outbreak of mpox Clade IIb prompted the World Health Organization (WHO) to declare a Public Health Emergency of International Concern. Since then, mpox cases, including Clade 1, have been reported in more than 126 WHO Member States.

As of April 28, 2025, mpox vaccination (JYNNEOS) services are commercially offered throughout the United States.

When the U.S. Centers for Disease Control and Prevention (CDC) reissued a Global Polio Alert on April 22, 2025, it identified 38 countries, indicating that the spread of poliovirus remains a public health emergency.

But the CDC did not mention Israel, but did include its neighbor, Gaza.

According to the Ministry of Health's Central Virus Laboratory, on April 24, 2025, poliovirus was detected in environmental samples in central Israel and the Jerusalem area, which has about 1 million residents. 

However, as of April 27, 2025, Israel's ministry had not reported any recent polio cases.

In March 2023, several children were confirmed with polio in Israel.

Over the past years, Israel has offered polio vaccination services throughout the country. But, as of March 2025, the administration of the live attenuated polio vaccine (oral) has been discontinued. 

In its place, the inactivated polio vaccine is now offered. This is the same polio vaccine provided in the United States.

Most African countries have switched to the nOPV2 polio vaccine over the past three years.

The CDC recommends that before travel to any listed destination, adults who previously completed the routine polio vaccine series may receive a single, lifetime booster dose of polio vaccine, which will extend their protection from this severe disease.