Vaccine News

According to local media, the Romanian Ministry of Health has reported two confirmed cases of leprosy, and two other suspected cases are undergoing evaluation.

These are Romania's first eprosy cases in more than 40 years.

Romaina-Insider reported Corina Criste, director of the Cluj Public Health Directorate, told Agerpres on December 12, 2025, that a case of leprosy was detected in Cluj-Napoca, he second-most populous city in the European country.

Health minister Alexandru Rogobete said he has ordered intensified epidemiological surveillance, expanded testing of contacts, evaluations of the working and living conditions of foreign employees, and the request for international assistance from the World Health Organization (WHO).

The WHO says leprosy, a chronic infectious disease caused by the bacterium Mycobacterium leprae, remains rare in Europe and is typically recorded among people originating from endemic regions in Asia, Africa, or Latin America.

In the United States, leprosy (Hansen's disease) is a nationally notifiable condition. Annually, the U.S. CDC detects around 150-250 cases of leprosy, with 225 in 2023 and 205 in 2024.

In 2025, Florida reported 36 leprosy cases, highlighting local transmission, especially in Brevard County.

The Centre for Health Protection (CHP) of the Department of Health in Hong Kong has announced that relevant departments will be conducting intensified mosquito control and prevention efforts along the Tsing Yi Nature Trails, a popular hiking area.

Published on December 9, 2025, this health alert is related to CHP's confirmation of a total of 78 chikungunya fever (CF) cases in 2025.

Among them, 10 were local cases, which were initially detected in late October 2025.

 On December 7, 2025, the CHP wrote that some confirmed CF cases had reportedly been bitten by mosquitoes while hiking along the Tsing Yi Nature Trails. These trails are situated in a countryside environment and cover a vast area, with the trails stretching approximately 7,000 metres. Along both sides of the trails, there are various natural breeding grounds for vectors, including puddles on soil surfaces and fallen leaves, which increase the risk of mosquito breeding.

This area is located east of Hong Kong Disneyland and northwest of the city of Hong Kong, which has welcomed over 40 million visitors this year.

The public should call 1823 in case of mosquito problems, stated the CHP.

Chikungunya is a mosquito-transmitted disease that is also vaccine-preventable.

As of December 12, 2025, chikungunya vaccines are offered at travel clinics in the United States and various countries.

The U.S. Centers for Disease Control and Prevention (CDC) today reported there are outbreaks of Rift Valley fever (RVF) in Mauritania and Senegal.

In a Level 1 Travel Health Notice published on December 11, 2025, the CDC says RVF is an acute viral hemorrhagic fever that causes illness in livestock and people.

However, there is currently no evidence of person-to-person transmission of RVF, which was first identified in 1931 in Kenya.

According to previous WHO data, in Mauritania, between September 27 and October 30, 2025, a total of 46 confirmed human cases of RVF, including 14 associated deaths (case fatality ratio: 30%), were reported in eleven districts from thirteen regions.

In Senegal, between September 20 and October 30, 2025, the Republic of Senegal reported a total of 358 confirmed human cases of RVF, including 28 deaths (case fatality rate: 7.8%).

The CDC says less than 2% of people infected with RVF will develop severe symptoms, which can include eye disease, hemorrhage, and encephalitis. Most people recover within one week, with treatment limited to supportive care.

While mortality is higher in severe cases, only about 1% of people who get RVF die, says the CDC.

An inactivated vaccine has been developed for human use, but it is not licensed or commercially available. It has been used experimentally to protect veterinary and laboratory personnel at high risk of RVF exposure.

In 2024 and early 2025, RVF vaccine candidates recieved funding rounds.

Since the beginning of 2025 and as of early December 2025, two countries in Europe have reported travel-related and locally acquired cases of chikungunya virus disease: France and Italy.

In France, the Health Ministry has reported 45 deaths linked to chikungunya. Among these deaths, 2 were neonatal patients.

As of December 3, 2025, the European Centre for Disease Prevention and Control's Epidemiological summary for week #49 indicates that the cumulative number of locally acquired cases in France is 788, with three clusters currently active.

The largest cluster is located in Antibes, part of the popular Côte d'Azur, where millions of vacationers visit annually. The Ministry's overall concern is that this mosquito-transmitted virus may have become endemic along the French Riviera since 2010.

As of December 11, 2025, the U.S. CDC advises international travelers to consult a travel vaccine expert about immunization options before visiting France.

The CDC recommends vaccination for travelers visiting an area with an active chikungunya outbreak. 

In the United States, travel clinics offer commercial chikungunya vaccination services.

According to the latest epidemiological update from the Pan American Health Organization (PAHO), countries in the Americas must address vaccination gaps as there has been a resurgence of pertussis, commonly known as whooping cough, which has been steadily increasing since 2023.

As of December 9, 2025, the PAHO reports that there has been a significant rise in cases since then, with 11,202 cases reported in 2023 and escalating to 66,184 cases in 2024.

In the United States, so far in 2025, 25,057 confirmed and probable cases of pertussis have been reported, including 13 deaths.

The states with the highest numbers of confirmed and probable pertussis cases in 2025 are Washington (2,003), California (1,585), and Florida (1,422).

"Whooping cough is a vaccine-preventable disease, but its resurgence highlights gaps in immunization and epidemiological surveillance," said Dr. Daniel Salas, Executive Manager of PAHO's Special Program on Integrated Immunization, in a press release.

"It is urgent that countries ensure high and consistent vaccination coverage, especially among children under five, to protect the most vulnerable and prevent outbreaks," he added.

The PAHO recommends that countries ensure vaccination coverage is above 95% in children and provide booster doses for pregnant women and healthcare workers, prioritizing maternity staff and caregivers of infants.

"Timely and complete vaccination, together with robust surveillance, is the most effective strategy to prevent whooping cough, a disease that can cause severe illness, complications, or even death, especially in unvaccinated children under one year," emphasized Dr. Salas.

Before departing for at-risk areas in December 2025, the PAHO and the U.S. CDC suggest international travelers speak with a travel vaccine consultant about immunization options.

Israel's Ministry of Health recently reported another death of an unvaccinated toddler from measles.

As of December 9, 2025, this fatality marks the 12th since the outbreak began in Jerusalem, Beit Shemesh, Bnei Brak, Harish, Modiin Illit, Nof HaGalil, Kiryat Gat, Ashdod, Safed, Netivot, Haifa, Tiberias, the Mateh Binyamin Regional Council, and Tekoa. 

Currently, 19 measles patients are hospitalized, most of them children under six who were not vaccinated. Four of them are in intensive care.

The Ministry stated in a media release that all the children who died were otherwise healthy and had no underlying medical conditions. These cases could have been prevented through vaccination.

'During the holiday season, anyone feeling unwell should avoid gatherings to prevent spreading this infectious disease,' added the Ministry.

According to Ministry of Health data, the first-dose measles coverage in targeted cities is about 85%.

According to the U.S. CDC's Level 1 Travel Health Notice, measles is an ongoing risk around the world, and more international travelers are getting infected.

Travelers can catch measles in many travel settings, including travel hubs such as airports and train stations, on public transportation such as airplanes and trains, at tourist attractions, and at significant, crowded events. Infected travelers can bring the disease back to their home communities, where it can spread rapidly among people who are not immune.

The CDC recommends that all travelers be fully vaccinated against measles before departing for any international destination. Measles vaccination services are offered at travel clinics and pharmacies in the United States.

The UK Health Security Agency (UKHSA) has identified an increase in the number of Shigella sonnei cases caused by a particular strain of the gastrointestinal pathogen.

Since October 2025, there has been a rise in Shigella infections in people returning to the UK from the Republic of Cape Verde. Of the 137 confirmed UK cases, most (109) reported recent travel to Cape Verde, an island country in the Atlantic Ocean off the coast of West Africa.

As of December 5, 2025, the UKHSA had initiated an outbreak investigation.

An outbreak of Shigella sonnei was also reported in Cape Verde in 2022, with cases among travellers from several European countries, including the UK.

The UKHSA says Shigella sonnei (S. sonnei) is a species of Shigella, a group of gastrointestinal bacteria that can cause severe diarrhoea, fever, and stomach cramps; rarely, it can cause sepsis in the immunocompromised.

S. sonnei is transmitted via contact with contaminated faeces either directly through person-to-person transmission or indirectly from contaminated food or water, or surfaces – infection is often linked to overseas travel to regions where shigellosis is endemic.

In 2023, there were 117 cases in England belonging to the 10 single-nucleotide polymorphism linkage cluster t10.1814.

Globally, most cases of shigellosis are in children younger than five years of age, but all ages can be affected. There is also a risk of sexual transmission among certain people.

In the United States, as of Week 43, the CDC reported about 14,000 Shigellosis cases, a significant decrease from 2024.

As of December 9, 2025, the CDC states there is no vaccine to prevent Shigella infection.