Travel Vaccine Breaking News

Recent experiences with the introduction of Chikungunya and Zika viruses to the United States could foretell what might occur with the Oropouche virus because all three arboviruses are maintained in an urban cycle between humans and arthropod vectors.

Both Chikungunya and zika viruses are transmitted by Aedes (Stegomyia) mosquitoes, which oviposit and develop in containers in and around homes. This makes persons more susceptible to mosquito exposure and, ultimately, infection.

In contrast, the primary Oropouche vector, the biting midge, is low-abundance in North America and primarily resides in tree holes in the southeast and midwestern U.S., says the U.S. CDC Emerging Infectious Disease, Volume 30, Number 11—November 2024.

As of October 7, 2024, local transmission of the Oropouche virus had not been reported in the United States, although 92 cases have been reported in travelers, primarily arriving from Cuba.

Cuba is in the midst of its peak rainy season, which is associated with increased vector abundance. This suggests that more travel-associated cases might be expected in the U.S., in particular, Puerto Rico.

The U.S. CDC wrote on October 1, 2024, that various factors are likely to affect the risk of the local spread of the virus, including the rate of introduction from travel-associated cases, the presence and distribution of the vectors and potential host reservoirs, and potential virus adaptation.

Should the virus infect wild bird populations in North America, it is possible that the Oropouche virus could become endemic, similar to the progression of the West Nile virus, says the CDC.

While Chikungunya has one approved vaccine and several Zika vaccine candidates are progressing in clinical research, Oropouche vaccine research is in its early stages in 2024.

Millions of people will be infected with the Dengue virus in the last few months of 2024 without being able to be treated with an approved antiviral.

Johnson & Johnson (J&J) announced on October 4, 2024, that it discontinued the Phase 2 field study evaluating the efficacy of investigational antiviral candidate mosnodenvir (JNJ-1802) for the prevention of dengue virus in adults.

Recent results from the Phase 2a human challenge study found that the compound induced antiviral activity against one of dengue's four viruses (DENV-3) in humans, compared to placebo.

J&J's decision to discontinue this study is part of a strategic reprioritization of the Company’s Communicable Diseases research and development portfolio. However, J&J will continue to support the fight against dengue by sharing study results with the medical community in the future.

Almost 4 billion people will live in areas at risk of dengue in 2024, including 26 countries recently highlighted by the U.S. Centers for Disease Control and Prevention (CDC).

According to the U.S. CDC, dengue symptoms can become severe within a few hours. See a healthcare provider if you develop a fever or have symptoms of dengue. Dengue can be found in the blood during the first week of illness.

Furthermore, time is of the essence as severe dengue is a medical emergency.

Dengue is a vaccine-preventable disease. Various approved vaccines have limited availability, and candidate vaccines are conducting late-stage research in October 2024.

According to the Pan American Health Organization (PAHO) chikungunya data dashboard, the Federative Republic of Brazil has reported 16 additional fatalities related to chikungunya virus (CHIKV) disease outbreaks in one month.

As of October 6, 2024, Brazil has confirmed 177 fatalities and 394,739 CHIKV cases this year.

Data from Brazil's Ministry of Health indicates that Minas Gerais has reported the most chikungunya cases, over 160,000, followed by Mato Grosso and Bahia.

Minas Gerais is Brazil's fourth-largest state by area, with a population exceeding 20 million.

In 2023, Brazil welcomed about 6 million foreign tourists, many visiting Minas Gerais.

The U.S. CDC confirmed in September 2024 that there has been evidence of chikungunya virus transmission in Brazil within the last five years, and vaccination may be considered for certain visitors.

As of October 6, 2024, Valneva SE's IXCHIQ® chikungunya vaccine has been approved by the U.S. Food and Drug Administration and recommended for travelers to endemic areas by the CDC.

IXCHIQ is commercially available at travel clinics and pharmacies in the U.S.

While the World Health Organization continues alerting international travelers to ongoing polio risks, two countries are the key focus. As of October 5, 2024, polio remains endemic in Pakistan and Afghanistan.

Unfortunately, two additional children were paralyzed by wild poliovirus type 1 in Pakistan, underscoring the expanding public health threat.

According to the Regional Reference Laboratory at the National Institute of Health, a female child from the Zhob district of Balochistan and a male child from the Tank district of Khyber Pakhtunkhwa have been affected,

This update indicates the total number of polio cases in 2024 is now 28. 

The Coordinator of the National Emergency Operations Center for Polio Eradication, Mr. Muhammad Anwarul Haq, stated that consistent polio campaign implementation in Balochistan and southern KP has been challenging for the Programme since last year due to factors such as lack of access to vulnerable children, security issues, vaccine hesitancy, and community boycotts. 

“Access challenges leave a cohort of unvaccinated children who have low immunity to fight off a polio infection. The Polio Programme is working closely with both provincial governments to increase vaccination coverage rates, build community trust, and provide integrated health service delivery for better health outcomes,” he said in a press release on October 2, 2024.

Polio is a highly infectious disease caused by the poliovirus, mainly affecting children under five. It invades the nervous system and can cause paralysis or even death. While there is no cure for polio, vaccination is the most effective way to protect children from this crippling disease, says the Global Polio Eradication Initiative (GPEI).

The U.S. CDC recently published a Travel Health Advisory that identified 37 destinations that have circulating poliovirus.

Before any international travel, make sure you are up to date on your polio vaccines, says the CDC. Adults who previously completed the routine polio vaccine series may receive a single, lifetime booster dose of the IPV polio vaccine.

Polio vaccination services are offered at travel vaccine clinics and pharmacies in the U.S.

Based on the Ministry of Health guidelines, the Republic of Rwanda's Development Board provided the following update on Marburg Virus Disease (MVD).

This viral hemorrhagic fever has claimed 12 lives from 41 cases over the past month.

As of October 4, 2024, no travel restrictions are currently in place, and all key tourist destinations, including Volcanoes National Park, Akagera National Park, Gishwati Mukura National Park, and Nyungwe National Park, are fully operational.

However, at points of entry, visitors should expect routine temperature checks and the provision of hand sanitizing stations at airports and other border crossings.

All people exiting Rwanda will undergo an MVD symptom screening questionnaire to ensure their well-being and the safety of others.

And tourists to this African country are advised to remain vigilant and practice good personal hygiene, such as avoiding close contact with individuals displaying symptoms such as high fever or severe headaches.

The U.S. CDC published an updated travel advisory on October 3, 2024, highlighting actions to prevent contracting MVD while visiting Rwanda.

As of today, no approved MVD vaccines are available.

The U.S. Centers for Disease Control and Prevention (CDC) confirmed last month that respiratory syncytial virus (RSV) is the most common cause of hospitalization among U.S. infants.

Since last year, when Beyfortus™ became the first U.S. FDA-approved single-dose, extended half-life monoclonal antibody (mAb) offering passive immunization to prevent lower respiratory tract infections caused by RSV, numerous researchers have focused on determining its real-world effectiveness.

The CDC has clarified that mAbs are not vaccines but offer disease protection.

According to a study's results published by The Lance in October 2024 (Volume 8, Issue 10p721-729), Beyfortus's estimated effectiveness against RSV-associated hospitalizations for bronchiolitis was 73% (61–84), corresponding to one hospitalization averted for every 39 (26–54) doses administered.

And in sensitivity analyses, nirsevimab remained effective against RSV-associated hospitalizations for bronchiolitis after emergency department attendance.

As of October 4, 2024, there is ample supply of Beyforus in the U.S., well ahead of the 2024-2025 RSV season's peak, expected in December or January.

The World Health Organization (WHO) reported today that West Nile Virus (WNV) had been detected in a child from Bagatelle, a parish in St. Thomas, located in Barbados, an island country in the Caribbean Sea.

On October 3, 2024, the WHO's Disease Outbreak News stated that this was the first human case of WNV detected in Barbados, which has a population of about 280,000.

Additionally, thousands of people visit Barbados yearly as it is a favorite vaccination destination and cruise ship port.

Additionally, no infections have been previously documented in birds or horses in Barbados, making this case both unusual and unexpected, wrote the WHO. Although no cases of WNV have been documented in birds or horses in the country, the virus may be circulating in these populations undetected. 

However, the WNV has previously spread throughout the Caribbean, likely via infected migratory birds.

The WHO's risk of international dissemination of WNV from Barbados is low, as the virus is primarily transmitted through mosquito bites, with birds as the natural hosts.

Based on available information on this event, WHO does not recommend any restrictions on travel and/or trade for Barbados and will continue to evaluate the epidemiological situation in Barbados. 

In the United States, 46 states have reported over 1,400 WNV cases in 2024.

From a prevention perspective, no approved West Nile virus vaccines are available for people in 2024.