Vaccine News

The Ministry of Health for the Federative Republic of Brazil recently confirmed a total of 1,019,033 dengue cases and 681 related fatalities this year.

As of April 12, 2025, São Paulo had reported the most dengue cases, at 590,850.

As of April 22, 2025, the U.S. Centers for Disease Control and Prevention (CDC) has identified more cases of dengue (1,481) than expected among U.S. travelers returning from countries with dengue outbreaks. 

In 2025, 54 travel-associated and one locally acquired dengue cases were reported in Florida.

Of dengue's four types, DENV-3 is the most common serotype identified, accounting for 84%.

To alert travelers to Brazil and other areas, the CDC reissued a Global Travel Health Notice on April 15, 2025, regarding Dengue outbreaks in the Americas. Additionally, the CDC encourages healthcare providers to increase testing of patients with symptoms related to dengue. 

Currently, dengue vaccines are unavailable in the U.S.

Recent maps released by the European Centre for Disease Prevention and Control (ECDC) indicate hotspots for tick-borne encephalitis (TBE) in Europe.

There are three distinct subtypes of tick-borne encephalitis virus: European, Far Eastern, and Siberian. They are found in different areas and cause disease of varying severity.

While the virus is already present in many European countries, as of April 15, 2025, the Central, Eastern, and Northern European regions have recently reported their first human cases of TBE or have noted an increase in infections.

In Europe, ticks become infected when they feed on small rodents that have the virus in their blood. People can become infected through the bites of infected ticks.

TBE is a vaccine-preventable disease that affects the central nervous system. Vaccination is an effective means of prevention.

In addition, taking personal protective measures, such as wearing long clothing, using tick repellent, avoiding tick-infested areas, and promptly removing any ticks from the skin, can significantly reduce the risk of infection.

According to the U.S. CDC, the TICOVAC tick-borne encephalitis vaccine is available in the United States and is approved for use in persons aged 1 year and older.

As of April 21, 2025, the CDC recommends that TICOVAC be considered for some travelers visiting high-risk areas.

The U.S. Department of Health and Human Services (HHS) recently issued a 'Stop Work Order' for GeoVax's investigational COVID-19 vaccine, GEO-CM04S1, which was being developed under a government-sponsored initiative.

According to GeoVax's press release on April 16, 2025, the U.S. Biomedical Advanced Research and Development Authority (BARDA) has decided to withdraw its funding, originally granted under Project NextGen (PNG), a $5 billion effort started under the previous U.S. administration to support the development of next-generation vaccines and therapies.

Of note, GEO-CM04S1 was the only multi-antigen/polyvalent COVID-19 vaccine candidate selected under the PNG initiative.

"While the recent HHS/BARDA Stop Work Order action was disappointing and surprising, our commitment to protecting vulnerable populations remains unchanged, and our clinical momentum is strong in support of our ongoing Phase 2 GEO-CM04S1 programs," commented David Dodd, Chairman and CEO of GeoVax.

GeoVax remains committed to addressing the critical medical need for GEO-CM04S1, particularly among the more than 40 million immunocompromised Americans and over 400 million people globally who remain inadequately protected by the current authorized COVID-19 vaccines.

Since the declaration of the emergency, both regional and global support has increased, particularly for the Democratic Republic of the Congo (DRC), the epicentre of the ongoing mpox outbreak. Despite progress, significant challenges remain.

In the first two months of 2025, 60 countries reported mpox, with the majority of cases and deaths reported from the African continent. 

The Africa CDC and WHO Joint Continental Mpox Plan has guided efforts to reduce this outbreak, focusing on ten key pillars: coordination, risk communication and community engagement, disease surveillance, laboratory capacity, clinical management, infection prevention and control, vaccination, research, logistics, and maintaining essential health services. 

As of April 20, 2025, mpox vaccination efforts are underway, with more than 650,000 doses administered in six countries, 90% of which have been administered in the DRC.

Overall, over a million doses have been delivered to 10 countries, with efforts ongoing to secure additional vaccine supplies. 

The leading mpox vaccine, JYNNEOS® (MVA-BN®, IMVAMUNE®), is produced by Bavarian Nordic A/S.

Along with the Continental Response Plan for Africa, the WHO has updated the global strategic plan to curb – and, where feasible, to stop – human-to-human transmission of mpox. The joint Continental Response Plan is aligned with the global strategy.

To alert international visitors of the ongoing mpox risk in Africa, the U.S. CDC issued a Level 2 - Practice Enhanced Precautions, Travel Health Advisory on April 1, 2025.

The CDC says people usually get mpox through intimate or close contact, including sex, with an infected person.

Mpox vaccination is recommended for people who anticipate sexual activities during travel to countries with ongoing person-to-person transmission of clade I mpox. In the U.S., the JYNNEOS vaccine is commercially available at clinics and pharmacies as of 2025.

The Florida Department of Health recently published its Arbovirus Surveillance update #15, disclosing that mosquito-borne diseases have been detected in residents and visitors this year.

While most cases of chikungunya, dengue, and malaria have been confirmed in Miami-Dade County, which is currently under a mosquito-borne illness alert, counties on both Florida's coasts have reported infections.

As of April 12, 2025, there was one confirmed travel-related case of chikungunya in 2025. Eleven instances of chikungunya onset in 2024 were reported in individuals with a travel history to Brazil (five), India (five), and Pakistan.

Throughout 2025, fifty-nine cases of dengue fever were reported among individuals who had traveled internationally, and one locally acquired case of dengue (DEN-3) was reported in Miami-Dade County. 

As of December 2024, 1,016 travel-associated dengue cases had been reported, primarily among visitors from Brazil, Cuba (567), and Puerto Rico. In 2024, 91 locally acquired dengue cases were reported from ten counties (Miami-Dade (50),

This year, ten travel-related malaria cases have been confirmed in the state of Florida. In 2024, 72 cases of travel-related malaria were reported in individuals with a history of visiting malaria-endemic areas, such as Africa (Nigeria) and Central and South America.

From a disease-prevention perspective, while chikungunya vaccines are amply available in Florida, dengue and malaria vaccines are only available in other countries.

As of April 19, 2025, the U.S. Centers for Disease Control and Prevention, Canada Health, and the United Kingdom have not issued vaccination requirements for visiting Florida; however, these agencies recommend staying up to date with recommended vaccines as the best travel advice.

West Africa continues to bear the scars of the Ebola outbreak that occurred a decade ago. From 2014 to 2016, Sierra Leone, Guinea, and Liberia faced the largest Ebola outbreak since the virus was first discovered in 1976.

This Ebola outbreak resulted in over 28,000 cases and 11,000 related fatalities.

As of April 2025, more than 30 Ebolavirus disease outbreaks have been reported.

The good news is that vaccines against Ebolavirus, the pathogen responsible for those outbreaks, have since been licensed, and stockpiles have been developed.

"All Ebola outbreaks that have occurred since we had a stockpile were quickly stopped – thanks to the vaccines and rapid other response measures," says Allyson Russell, an epidemiologist and senior programme manager in Gavi's High Impact Outbreaks team, in a GAVI news article published on April 15, 2025.

However, these Ebola vaccines aren't effective against the other three orthoebolaviruses that cause severe disease, including the Sudan virus outbreak in the Republic of Uganda.

Uganda's Ministry of Health declared its eighth Sudan Ebolavirus outbreak in January 2025. Since then, about 14 cases, including four related fatalities, have been reported.

To alert the international community, the U.S. government recently updated a Level 2 Travel Health Advisory.

On March 12, 2025, the Centers for Disease Control and Prevention confirmed a Sudan virus outbreak in the districts of Kampala, Wakiso, Jinja, Mbale, Kyegegwa, Kabarole, and Ntoroko.

Still, the unpredictability and rapid progression of Ebola outbreaks make testing vaccine efficacy challenging.

As of April 19, 2025, no vaccines have been approved to protect people against the Sudan Ebola virus. However, candidate vaccines are being tested in the Solidarity Against Ebola human clinical studies in Africa.

Over the past decade, the Republic of Costa Rica has seen a significant increase in tourism from the United States and the United Kingdom, which has dramatically boosted the local economy.

However, the Tico Times reported on April 17, 2025, that the positive tourism trend has suddenly shifted in 2025.

This local media outlet's article, "Why Tourists Are Vanishing," reported that in February 2025, only 270,810 tourists arrived in Costa Rica by air, a 7% decrease from the previous year.

According to the Costa Rican Tourism Board, this data marks six consecutive months of decline.

The reasons behind these decreases include tourists facing higher costs due to the local currency, rising insecurity, an increase in tourists reporting crimes such as assaults and thefts, and eating shellfish.

On April 15, 2025, the U.S. Embassy confirmed a ban on the harvesting and sale of bivalve mollusks (such as piangua, mussels, clams, and oysters) from the coastal area between Playa Herradura and the mouth of the Guacimal River.

According to local authorities, recent tests in shellfish from this region detected paralytic marine toxins, a serious type of toxin that can lead to shellfish poisoning.

Additionally, mosquito-borne diseases such as chikungunya, dengue, and Zika are once again affecting both residents and international visitors.

The Ministry of Health and the Pan American Health Organization have confirmed, as of April 18, 2025, that seven cases of chikungunya have been reported so far this year, 1,957 cases of dengue, six cases of malaria, and six cases of Zika.

Recently, the Ministry of Health announced positive news as the local vector control teams are proactively eliminating mosquito breeding sites and fumigating houses to reduce these infections.

Moreover, approved vaccines to prevent chikungunya and dengue are available in various countries this year.

While tourists have other Central American and Caribbean destinations to visit, Costa Rica's lush mountains and delightful beaches will continue to welcome visitors during the summer of 2025.