Vaccine News

The Government of the Hong Kong SAR's Center for Health Protection (CHP) of the Department of Health today announced a third locally acquired case of chikungunya fever (CF) in a middle-aged man living in the Kwai Tsing District and working in Sheung Wan.

As of November 4, 2025, the CHP will conduct genome analysis to determine whether it has epidemiological linkage to the imported cases confirmed earlier in Hong Kong. Investigation is ongoing.

Kong Kong's initial CF case was reported on October 28, 2025.

In response to the new local case, the CHP today has conducted an inter-departmental meeting with various departments and relevant organisations.

To alert international travelers to the expanding CF health risk in this region, the U.S. CDC published a Level 2—Practice Enhanced Precautions —Travel Health Notice in late August 2025.

The CDC stated that 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 with screens on the windows and doors. 

Additionally, the CDC recommended vaccination for certain travelers visiting areas with chikungunya outbreaks. In general, vaccination against chikungunya should be deferred until after delivery for pregnant women.

In the United States, approved chikungunya vaccines are commercially available at travel clinics and pharmacies.

The Florida Department of Health recently published its Vaccine-Preventable Diseases Surveillance Report #44 for 2025, revealing a continuation of locally acquired and travel-related mosquito-transmitted disease cases.

As of November 1, 2025, Chikungunya, Dengue, and Malaria patients were primarily identified along Florida's southeast coast.

This year, 42 travel-related Chikungunya cases have been confirmed in Broward, Collier, Lake, Miami-Dade, Palm Beach, and Seminole counties. The countries of origin included Bolivia, Brazil, Cuba, India, and Indonesia.

Also, the health department reported 321 cases of Dengue fever among individuals who had traveled internationally, with over 180 cases related to travelers from Cuba and 14 from Puerto Rico. Additionally, 53 locally acquired Dengue cases were reported in Hillsborough, Miami-Dade (16), Pasco, and Brevard (35) counties.

Furthermore, 41 travel-related Malaria cases have been confirmed in Florida, 15 related to travel to Nigeria.

To alert visitors to these health risks, Alachua, Bay, Clay, Duval, Hillsborough, Lafayette, Leon, Pasco, and Pinellas counties are under a mosquito-borne illness advisory. Brevard, Escambia, and Miami-Dade Counties remain under a mosquito-borne illness alert.

However, the U.S. CDC has not issued a Travel Health Notice for Florida regarding these disease risks.

The first human cases of the Zika virus (ZIKV) were detected in 1952; researchers have been working to develop a preventive vaccine. 

This effort is essential as 31 countries and territories have reported cases of congenital microcephaly and other central nervous system malformations associated with Zika virus infection.

To address the unmet medical need, Valneva SE, a France-based specialty vaccine company, has been conducting phase 1 clinical trials, including its second-generation candidate.

Today, Valneva announced positive results of its current Phase 1 clinical trial (VLA1601-102) investigating the safety and immunogenicity of VLA1601, its second-generation adjuvanted inactivated vaccine candidate against Zika.

As of November 4, 2025, the Company confirmed that two doses of VLA1601 were immunogenic across all five treatment arms investigated (i.e., alumadjuvanted Low, Medium, and High antigen dose; Low with additional adjuvants).

The strongest immune response was observed in the double-adjuvant treatment arms (Low+alum+3M-052-AF and Low+alum+CpG1018) with statistically significantly higher neutralizing antibody titers (Geometric Mean Titers - GMTs) at Day 43 and Day 57 than in the single-adjuvant (alum) treatment arm.

And the immune response induced by the double-adjuvanted VLA1601 was successfully improved compared to the first-generation vaccine candidate, with higher peak seroconversion rates (>93% vs 86%) and peak Geometric Mean Fold Increase in titers (> 56-fold vs > 7-fold).

Juan Carlos Jaramillo, M.D., Chief Medical Officer of Valneva, commented in a press release, "We are pleased by the notable safety and immunogenicity results demonstrated for our Zika vaccine candidate and especially our double-adjuvantation results."

Should this vaccine development effort achieve US-FDA approval, international travelers, especially pregnant women, would be very interested in discussing immunization options with healthcare providers. Since 2013, 31 countries and territories, including Costa Rica and Puerto Rico, have reported cases of congenital microcephaly and other central nervous system malformations associated with Zika virus infection.

As of November 4, 2025, over 24,000 Zika cases and four related fatalities have been reported in the Region of the Americas this year.

According to the World Health Organization, mpox outbreaks remain a global health risk. Since mpox is a vaccine-preventable disease, access to the approved vaccine is essential.

To address this need, Bavarian Nordic A/S, a global vaccine company, recently issued the following clarification regarding the Health Emergency Preparedness and Response Authority (HERA) framework agreement.

The initial order for 750,000 doses of the MVA-BN (JYNNEOS) smallpox/mpox vaccine announced on October 31, 2025, will be delivered in 2026 and is the result of a new joint procurement contract by the European Commission through HERA.

This represents the second order received in 2025, following the earlier award of a contract option from the U. S. Biomedical Advanced Research and Development Authority in the U.S. Department of Health and Human Services, announced in May.

Bavarian Nordic anticipates additional orders for MVA-BN over the course of the following year.

As of November 3, 2025, in the United States, the JYNNEOS vaccine is commercailly available at various health clinics and pharmacies.

Chikungunya is a viral disease transmitted to humans through infected mosquitoes. The first known outbreak occurred in 1952. In the past year, 100 countries have reported chikungunya outbreaks to the the European Center for Disease Prevention and Control (ECDC).

In Italy, the National Institute of Health has reported 419 chikungunya cases in 2025, with approximately 370 confirmed as locally transmitted, primarily in the northern region of the country.

According to ECDC's Week 44 report on October 29, 2025, the largest cluster of cases is located in Carpi, San Prospero, Soliera, Novellara, Cavezzo, Modena, Nonantola, Correggio, Novi di Modena, and Cesenatico.

In the United States, the CDC says locally acquired chikungunya cases have not been reported since 2019.

However, as of late November 2025, the CDC confirmed 19 travel-related cases in states such as Florida, several of which were linked to visitors from Cuba.

The CDC currently recommends that international travelers visiting outbreak areas speak with a travel vaccine provider about immunization options. Approved chikungunya vaccines will be available at clinics and pharmacies in November 2025.

The World Health Organization (WHO) recently published the 59th situation report for the multi-country outbreak of mpox, which provides details on the global epidemiological situation for mpox.

As of November 2, 2025, the WHO stated all clades of the monkeypox virus (MPXV) continue to circulate across all regions.

In September 2025, 42 countries reported a total of 3,135 confirmed cases, including 12 related fatalities.

More than 80% of these cases were reported in the African Region.

The WHO wrote, 'In light of expanding community transmission of clade Ib MPXV and its detection among men who have sex with men, WHO currently assesses the public health risk as moderate for men who have sex with men and low for the general population in contexts outside historically endemic areas.'

From a prevention perspective, More than 684,000 doses of MVA-BN (JYNNEOS) and 118,000 doses of LC16 have been administered in the Democratic Republic of the Congo, which accounts for more than 61% of people vaccinated in African countries.

Other countries that recently reported mpox are developing national mpox vaccination plans and are encouraged to consider dose-sparing options of the MVA-BN vaccine.

Additional doses have been donated and procured, and partners continue to work together to support access to mpox vaccines and secure operational funds for implementation of national mpox vaccination plans.

In the United States, the JYNNEOS vaccine is offered at various health clinics and pharmacies and is recommended for at-risk individuals.

The Czech Republic (Czechia) is currently experiencing what may be the largest hepatitis A epidemic in the last 46 years, as reported by Ivana Lesková from MF DNES.

Since the arrival of the virus from Slovakia in April 2024, the State Institute of Health has documented 2,141 cases of hepatitis A and 26 related fatalities, including ten in Prague.

As of October 28, 2025, the Institute of Health has noted a significant increase in demand for hepatitis A vaccinations.

This year alone, more than 127,000 doses have been administered—almost double the total from last year. Due to this surge in demand, there are currently shortages of the vaccine.

However, the State Institute for Drug Control has announced to the local media that extraordinary vaccine shipments are on their way to the Czech Republic.

This vaccine shortage extends the HepA risk to over 20 million international travelers who may visit Czechia this year.

Currently, the U.S. CDC recommends that unvaccinated travelers aged 1 year or older visiting Czechia in 2025 speak with a healthcare provider about immunization options. 

For international travelers who are allergic to a vaccine component, they should receive a single dose of immune globulin, which provides adequate protection for up to 2 months, depending on the dosage given.

Unvaccinated travelers who are over 40 years old, are immunocompromised, or have chronic medical conditions planning to depart for a risk area in less than 2 weeks should get the initial dose of vaccine and, at the same appointment, receive immune globulin, says the CDC.