Vaccine News

The Centre for Health Protection (CHP) of the Department of Health recently confirmed a total of five Chikungunya Fever (CF) cases have been recorded in Hong Kong in 2025, all of which were travel-related.

Additionally, as of August 10, 2025, one probable (local) case of this disease has been identified.

The CHP says that given the occurrence of multiple imported cases in Hong Kong, there is a risk of secondary local transmission via mosquitoes.

The CHP issued a letter reminding doctors to arrange testing for patients presenting symptoms consistent with CF, regardless of their travel history. Testing should also be considered for patients showing any symptoms of CF who have a travel history to affected areas, based on clinical judgment. The CHP's Public Health Laboratory Services Branch is providing free testing to ensure rapid diagnosis.

According to the U.S. CDC's Level 2 - Practice Enhanced Precautions, Travel Health Advisory issued on August 1, 2025, there is a substantial Chikungunya outbreak in Guangdong Province, China.

Most local and travel cases have been reported in Foshan City, which is located north of Hong Kong.

The CDC writes, 'You can protect yourself by preventing mosquito bites, which includes using insect repellent; wearing long-sleeved shirts and pants; and staying in places with air conditioning or that have screens on the windows and doors.'

Additionally, vaccination is recommended for travelers who are visiting an area with a chikungunya outbreak. Two chikungunya vaccines are approved for use in the United States and are available at travel vaccine retailers.

At present, there is no locally registered Chikungunya vaccine available in Hong Kong. 

The producer of the Yellow Fever vaccine, Sanofi, recently advised the United Kingdom's National Travel Health Network and Centre (NaTHNaC) that the yellow fever vaccine Stamaril® (17D-YFV, 17D-213) is expected to be available for ordering in the UK by August 15, 2025.

Since August 1, 2025, the UK has had limited access to Stamaril.

The NaTHNaC says this YF vaccine's availability is subject to change, and this should be taken into account when advising the traveller. Where a provider is unable to provide the YF vaccine during this vaccine shortage, the provider is expected to proactively research alternative supplies in their locality and direct international travellers accordingly.

If attempts to source the YF vaccine are unsuccessful, health professionals can contact the NaTHNaC advice line to discuss with an advisor.

Regardless of vaccine access in the UK, various countries, such as Brazil and Colombia, require proof of YF vaccination upon arrival in 2025.

As of August 10, 2025, the travel vaccination centers in the United States have access to the YF-VAX vaccine, which Sanofi also produces.

While the European CDC says Chikungunya is not endemic in mainland EU/EEA, outbreaks have been reported in 2025.

According to the latest ECDC Communicable Disease Threats Report, as of August 6, 2025, France and Italy have reported locally acquired cases of chikungunya virus disease:

France's health authorities have identified 63 locally acquired cases of Chikungunya across 16 different local administrative units.

Currently, there are eleven active clusters. Notably, cases were reported for the first time in the Pyrénées-Atlantiques department, with three instances in one cluster. Additionally, three cases representing a new cluster were reported in Gard.

In the active clusters located in the departments of Corse-du-Sud, Isère, Hérault, and Bouches-du-Rhône, two new cases have been reported in each cluster.

The most significant clusters are in southern France, specifically in Salon-de-Provence, Grans, and Lambesc in the Bouches-du-Rhône department, as well as Grosseto-Prugna in the Corse-du-Sud department, with each cluster consisting of 13 cases.

In Italy, two clusters remain active.

For the current risk assessment of chikungunya virus disease in mainland EU/EEA, please visit the ECDC's dedicated chikungunya webpage.

Fortunately, chikungunya vaccines are approved for use in Europe and the United States. 

The U.S. CDC advises international travelers to speak with a travel vaccine expert regarding immunization options. Chikungunya vaccines are commercailly offered at select retailers.

While local cases of malaria are rarely reported in the United States, there were 10 cases across four states in 2023.

According to a news release, Washington State may soon be added to this list of affected areas.

On August 6, 2025, a press release announced that a resident of East Pierce County, who had not traveled recently, was diagnosed with malaria in early August. Dr. James Miller, the Tacoma-Pierce County Health Officer, stated, "The risk of contracting malaria in Pierce County remains very low."

"Malaria is generally rare in the U.S., and the vast majority of cases occur after exposure to countries where malaria transmission is ongoing."

In the U.S., approximately 2,000 to 2,500 cases of malaria are reported each year, primarily linked to travel. In 2025, states like Florida have reported numerous travel-related cases (28), related principally to travelers from Cuba.

Previously, Florida reported local cases on both coasts.

It is important to note that malaria does not spread directly from person to person.

Malaria is a mosquito-borne disease caused by a parasite. The incubation period—the time from infection to the onset of symptoms—ranges from 7 to 30 days.

Malaria can be treated and cured with prescription antimalarial medications; however, if not diagnosed and treated quickly, it can become life-threatening.

In Africa, two approved vaccines that help prevent malaria are currently in use. However, as of August 7, 2025, these vaccines are not available in the U.S.

The World Health Organization (WHO) today published an update on the Nipah virus (NiV) outbreak in India. Since 2018, Kerala has experienced nine outbreaks of the Nipah virus, which is part of a pattern of recurring spillovers.

As of August 6, 2025, Kerala State health officials have reported four cases to the WHO since mid-May, two of which have been fatal.

Of the latest four patients in India's southwest area, two are from Malappuram district, where previous cases had been reported. The other two are from Palakkad district, which had not seen any earlier cases.

According to the WHO, NiV infection is a bat-borne zoonotic disease transmitted to humans through infected animals, or food contaminated with saliva, urine, and excreta of infected animals.

Since 1998, NiV outbreaks have been reported in Bangladesh, India, Malaysia, the Philippines, and Singapore.

Currently, the risk of international disease spread is considered low, as there is no evidence of human-to-human transmission of NiV internationally in this event.

The WHO wrote that, with no licensed vaccine or treatment available, public health efforts should focus on raising awareness of risk factors and promoting preventive measures to reduce exposure to the virus, and on early case detection supported by adequate intensive supportive care.

In 2023, the Coalition for Epidemic Preparedness Innovations invested $$100 million in four Nipah vaccine candidates: Auro Vacc, PATH, Public Health Vaccines, the University of Tokyo, and the University of Oxford.

Recently, the U.S. government announced a project in 2025 that would support the development of a Nipah monoclonal antibody (MBP1F5), currently undergoing Phase 1 testing in India and Bangladesh.

According to Mexico's health ministry's latest epidemiological bulletin, an older woman recently died from New World Screwworm (NWS) in the city of Candelaria in Campeche state.

This disease is spread by the fly Cochliomyia hominivora, which deposits larvae that burrow into the flesh of livestock, wildlife, pets, and sometimes people, causing severe damage.

The health ministry has reported 35 human cases of NWS in 2025, mainly from Chiapas state.

Mexico and partners in the United States have been battling a recent northward spread of the fly through Central America.

The US Department of Agriculture writes that in 2023, NWS detections in Panama increased from an average of 25 cases per year to more than 6,500 cases in one year.

Since then, NWS has been detected in Costa Rica, Nicaragua, Honduras, Guatemala, Belize, El Salvador, and Mexico, north of the biological barrier that has successfully contained this pest to South America for decades.

On July 9, 2025, Mexico's National Service of Agro-Alimentary Health, Safety, and Quality reported a new case of NWS in Ixhuatlan de Madero, Veracruz, Mexico, which is approximately 370 miles south of the US/Texas - Mexico border.

“The United States has promised to be vigilant, and after detecting this new NWS case, we are pausing the planned port reopenings to quarantine further and target this deadly pest in Mexico. We must see additional progress in combating NWS in Veracruz and other nearby Mexican states to reopen livestock ports along the Southern border," commented US Secretary of Agriculture Brooke L. Rollins, in a press release.

As of August 6, 2024, there are no NWS vaccines available. 

Since the start of the outbreak in May 2022,  the Monkeypox virus (MPXV) clade I and clade II have been detected circulating in multiple countries, including those in Europe.

As of July 28, 2025, there have been 24,995 confirmed cases of mpox (MPX) reported from 29 EU/EEA countries.

Over the last seven weeks, the European CDC reported 12 EU/EEA countries reported 94 mpox cases. 

These countires are led by Germany (56), followed by Spain (14), France (6), Netherlands (5), Belgium (3), Czechia (2), Portugal (2), Sweden (2), Ireland (1), Italy (1), Romania (1) and Slovenia (1).

The ECDC stated on August 1, 2025, that the overall risk remains low for most European populations. However, as summer travel and Pride season are ongoing, transmission of the MPXV could increase, and it is essential to raise awareness of this vaccine-preventable disease.

To the west of Europe, the United Kingdom has reported 14 mpox cases this year in England. As of the end of June 2025, most of these mpox cases have reported direct or indirect links to travel to countries where mpox clade Ib is circulating.

As of August 5, 2025, an effective and safe mpox vaccine (JYNNEOS®, MVA-BN®, IMVAMUNE®) is available throughout Europe and in the United States.