Vaccine News

The Government of Hong Kong's Centre for Health Protection (CHP) of the Department of Health announced today that Hong Kong has recorded a total of 18 confirmed travel-related Chikungunya Fever (CF) cases this year.

The CHP data for September 17, 2025, indicates a substantial increase from 2016 to 2019, during which Hong Kong recorded between one and 11 imported cases annually.

Additionally, the Food and Environmental Hygiene Department continues to conduct vector investigations and targeted mosquito control operations. It intensifies mosquito prevention and control measures at the residences of recently confirmed patients, as well as at locations visited after the onset of symptoms.

The public should call 1823 in case of mosquito problems.

Furthermore, the CHP's Port Health Division continues to step up inspections at boundary control points, reminding cross-boundary public transport operators and other relevant parties to ensure good environmental hygiene and the practical implementation of anti-mosquito measures.

Currently, there are no travel restrictions when visiting Hong Kong, a popular tourist destination.

According to recent information from the Guangdong Provincial Disease Control and Prevention Administration, although the situation in Guangdong Province has been under control since late August 2025, with only sporadic new cases reported daily, Chikungunya outbreaks continue in many countries worldwide.

In Asia, India and Indonesia recorded more than 32,000 and 17,000 CF cases, respectively, in 2025. 

As of early 2025, the U.S. CDC maintains a Level 2 - Practice Enhanced Precautions, Travel Health Advisory, focused on Chikungunya outbreaks for countries in Asia and the Indian Ocean.

The CDC recommends vaccination for specific travelers visiting an area with a Chikungunya outbreak.

As of mid-September 2025, the UK states that, on an exceptional basis, vaccination can be considered for individuals aged 12 years and older. In these situations, further expert advice should be considered.

The final decision on vaccination rests with the health professional and the traveller after a detailed risk assessment has been performed.

Since the beginning of 2025, the European Centre for Disease Prevention and Control (ECDC) has identified ten countries in Europe reporting human cases of West Nile virus (WNV) infection: Albania, Bulgaria, France, Greece, Hungary, Italy, Romania, Serbia, Spain, and Türkiye.

As of September 17, 2025, the ECDC reported Spain has confirmed 8 WNV cases this year.

In southern Spain, north of Gibraltar, mosquito control efforts have begun after infected mosquitoes carrying WNV were found in Benalup-Casas Viejas, in the Cadiz region. This city has a population of 6,754, but is a tourist favorite in 2025.

The Andalusian Health Department recently announced that the Seville municipality of Guillena is now on alert after the virus was detected in mosquitoes and confirmed the first case of WNV in the autonomous community.

In total, 109 Andalusian municipalities are at a high risk level or in an alert area situation, distributed across all provinces.

Spain's initial human case of autochthonous WNV lineage two was confirmed in 2024. This detection linked the strain to Central Europe. In total, 158 people were infected, with 20 dying from related complications in 2024.

From a disease prevention perspective, the U.S. CDC recommends avoiding mosquito bites since there are no WNV vaccines available in 2025.

Additionally, the CDC reports an increased risk of exposure to poliovirus in Spain, advising visitors to be fully vaccinated.

Now in its third decade of serving travelers in Central Texas, Austin–Bergstrom International Airport welcomed over two million visitors last month, many of whom arrived from overseas.

Unfortunately, this year, eight visitors to Travis County, and Austin, Texas, contracted the Dengue virus while traveling abroad.

Last year, Travis County reported 18 travel-related cases of Dengue, the most in Texas.

According to the Texas Department of State Health Services' (DSHS) arbovirus weekly report #36, there have been 31 travel-related Dengue cases reported in Texas this year.

This news is relatively positive compared to 2024, when 143 imported Dengue cases and one related fatality occurred across 23 Texas counties.

Texas is not alone in reporting fewer Dengue cases in 2025.

Throughout the United States, 3,045 cases of mosquito-transmitted Dengue have been confirmed this year.

In 2024, 53 U.S. jurisdictions reported 9,391 Dengue cases.

Only a few states, such as Florida, reported locally acquired Dengue cases last year.

And in the Region of the Americas, as of epidemiological week 34, a total of 3,740,133 suspected cases of Dengue were reported in 2025. This data represents a 68% decrease compared to the same period in 2024.

To enhance disease detection, the U.S. Centers for Disease Control and Prevention (CDC) advised clinicians in July 2025 to consider Dengue in patients with fever who live in or have recently traveled to areas with a risk of Dengue.

Furthermore, to alert international travelers to this health risk, the CDC reissued a Global Travel Health Notice on August 21, 2025, regarding Dengue outbreaks in the Americas, Africa/Middle East, and Asia/Pacific regions, in countries such as India, Singapore, Thailand, the Philippines, Malaysia, and Myanmar. 

From a disease prevention perspective, the CDC says mitigating mosquito bites is the best option, as access to Dengue vaccines in the USA is currently limited to children in Puerto Rico.

Since the summer of 2025 has ended, and most children have returned to school, parents are asking when the best time is to get the annual flu shot. Since it takes a few days for influenza vaccines to take effect, timing is a crucial factor.

To help guide answers, the U.S. Centers for Disease Control and Prevention (CDC) recently published the results of tests performed by clinical laboratories nationwide.

Nationally, during Week 36, the percentage of respiratory specimens testing positive for the influenza virus in clinical laboratories was 0.4%.

The CDC also confirmed that, based on NCHS mortality surveillance data available as of September 4, 2025, 0.06% of the deaths that occurred during the week ending Week 36 were attributed to influenza. 

Unfortunately, a total of 280 influenza-associated pediatric deaths occurred during the 2024-2025 season.

This data is the highest number of pediatric deaths reported in any non-pandemic influenza season since the condition became reportable in 2004.

To reduce these pediatric deaths, the CDC and most state health departments recommend that eligible children receive the flu shot beginning in September each year.

Additionally, adults and children should be protected when traveling to a country reporting influenza outbreaks, such as Australia. Influenza vaccination is recommended for all Australians aged 6 months and older for the 2025-2026 flu season.

As of September 15, 2025, most pharmacies in the USA offer vaccine appointments to streamline the flu shot programs.

Vaccination of frontline health workers and contacts of people infected with Ebola virus disease has begun in Bulape health zone in the Democratic Republic of the Congo (DRC) 's Kasai Province, where an outbreak of the disease was declared.

The World Health Organization (WHO) stated on September 14, 2025, that an initial 400 doses of the Ervebo® Ebola vaccine, prepositioned in the capital, Kinshasa, have been delivered to Bulape, one of the current hotspots of the DRC's 16th Zaire Ebolavirus outbreak.

Additional Ervebo doses will be delivered to the affected localities in the coming days.

In addition, treatment courses of the Ebanga™ monoclonal antibody therapy (Mab114) drug have also been sent to treatment centres in Bulape for clinical care.

In the outbreak area, WHO has so far deployed 48 experts in disease surveillance, clinical care, infection prevention and control, logistics, and community engagement.

In countries neighboring the DRC, the WHO is working with national authorities to bolster operational readiness, enabling the rapid detection of Ebola cases and the prompt initiation of measures to curb further spread of the lethal virus.

As of September 15, 2025, the WHO assesses the overall public health risk posed by the ongoing outbreak as high at the national level, moderate at the regional level, and low at the global level.

To alert international travelers, the U.S. CDC issued a Level 1 - Practice Usual Precautions, Travel Health Advisory regarding this Ebola outbreak. 

The CDC wrote on September 8, 2025: "While not commercially available, there is an FDA-approved vaccine for the prevention of the Zaire Ebola virus." It is presently available to select individuals in specific occupations (e.g., outbreak responders).

For more information on vaccines, please consult with your healthcare provider to discuss eligibility and access to the Ebola vaccine.

According to recent data published by the Japan Institute for Health Security (JIHS), Japan reported the most significant number of pertussis cases to date in 2025.

As of August 30, 2025, there have been a total of 72,448 pertussis cases reported in Japan this year.

Cases have been detected in all 47 Japanese prefectures, with Tokyo (5,846), Niigata (3,496), and Saitama (3,857) reporting the highest totals.

To help reduce these cases, the first round of pertussis routine immunization is administered three times for young children in Japan.

Furthermore, the JIHS recommends pre-arrival pertussis vaccination for individuals at risk, such as pregnant women and infants.

Unfortunately, the United States is confronting similar data.

Preliminary data show that more than six times as many cases were reported in 2024 compared to 2023.

However, the U.S. CDC reports that cases of pertussis have been trending downward since a peak in November 2024.

When planning a visit to Japan in 2025, the CDC advises travelers to be up to date with routine and travel vaccinations. This recommendation includes the Diphtheria-Tetanus-Pertussis vaccine.