Vaccine News

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.

The travel advisory for the Republic of Mali, a landlocked country in West Africa, has been elevated to Level 4 status by the U.S. Department of State.

As of October 24, 2025, the State Department stated U.S. residents 'should not visit Mali for any reason.'

Furthermore, the U.S. government cannot provide routine or emergency services to U.S. citizens outside Bamako due to safety risks.

Have a plan to leave in an emergency that does not depend on U.S. government help, and enroll in the Smart Traveler Enrollment Program to receive digital alerts from the U.S. embassy. Enrolling helps the U.S. embassy contact you or your emergency contact in an emergency.

About 200,000 international travelers visit Mali annually.

From a health perspective, medical services for routine and emergency procedures are limited in Mali. Health facilities are available in major cities. It may be harder to find adequate health care in rural areas.

The U.S. CDC previously issued Level 1: Practice Usual Precautions for Mali regarding dengue and measles outbreaks. In addition to these diseases, the CDC recommends vaccination against yellow fever, typhoid, polio, and malaria medications when visiting Mali in 2025.

These vaccines and medications are offered at travel pharmacies.

The Los Angeles County Department of Public Health (LACDPH) recently confirmed the first local death from the West Nile virus (WNV) in the 2025. The resident of the San Fernando Valley was hospitalized and died from a neurological illness caused by severe West Nile virus.

A total of 14 West Nile virus infections have been documented in Los Angeles County in 2025, excluding Long Beach and Pasadena. Half of the infected people live in the San Fernando Valley region.

Public Health reports West Nile virus cases every year, generally from June to November, as the virus is endemic in the region.

According to LACDPH, about 1 in 150 people will have severe WNV symptoms that may include high fever, stiff neck, muscle weakness, and sometimes rash. Symptoms usually appear 3 to 14 days after being infected.

West Nile virus is the most common mosquito-borne disease affecting residents of LA County, which has also reported locally acquired dengue cases in 2025.

"To the family and friends grieving the loss of a loved one due to West Nile virus, we extend our heartfelt condolences,” said Muntu Davis, MD, MPH, Los Angeles County Health Officer, in a press release on October 24, 2025.

“This tragic loss reminds us how dangerous mosquito-borne diseases like West Nile virus and dengue can be. Protect yourself and your neighbors by using insect repellent, getting rid of standing water where mosquitoes breed, and keeping window and door screens in good repair. Small actions like these can make a big difference in preventing illness.”

In collaboration with local vector control agencies, Public Health monitors the risk of WNV infection. It actively engages residents to provide information about reducing the risk by promoting protective measures against mosquitoes.

As of October 27, 2025, there is no WNV vaccine available in the USA.

Since the Zika virus was first detected in the Americas in 2015, the Pan American Health Organization (PAHO) and the World Health Organization (WHO) have reported cases from 52 countries and territories in the region.

As of October 24, 2025, the PAHO Zika data dashboard indicates that there have been over 23,000 cases and four related fatalities in the Region of the Americas this year.

The current leaders are Brazil (21,762), Bolivia (1,012), and Argentina (849).

And in the Central America Region, Costa Rica, El Salvador, and Guatemala are the unfortunate leaders in reporting this mosquito-transmitted disease.

This PAHO data aligns with 2024, when 44,480 cases and two related fatalities were confirmed across all countries for the entire year.

Last year, Brazil reported about 90% of all cases.

In the Americas, one in four Zika-infected people may develop symptoms, but in those who are affected, the disease is usually mild, with symptoms lasting between 2 and 7 days. The clinical appearance is often similar to dengue or chikungunya.

According to the PAHO, Zika virus infection during pregnancy poses severe risks to the fetus, ranging from congenital Zika syndrome to microcephaly to milder neurodevelopmental issues.

From a severity perspective, there is scientific consensus that Zika is a cause of Guillain-Barré syndrome.

As of October 2025, the UK travel advisory says that since there is no vaccination or medication to prevent Zika infection, women should avoid becoming pregnant while traveling to at-risk countries such as those listed above, and for 2 months after their last possible Zika virus exposure.

Prevention involves reducing mosquito populations and avoiding bites, which occur mainly during the day, says the UK advisory.

In the future, a Zika vaccine candidate may be approved for human use.

The Government of the Hong Kong SAR Center for Health Protection (CHP) of the Department of Health today published an update on chikungunya fever (CF) cases.

As of October 23, 2025, Hong Kong has recorded 43 confirmed, imported CF cases this year.

Among these, a patient recently passed away.

The CHP says severe symptoms and deaths caused by CF are extremely rare, with a mortality rate of less than one in 1,000, and the conditions of the other 42 patients are mild.

The occurrence of severe complications is mainly related to the patients' underlying health conditions. Elderly persons (particularly those aged 65 or above), young children (particularly infants under 1 year old), pregnant women, and persons with chronic illnesses (such as hypertension, diabetes, or heart disease) are at higher risk of developing complications after contracting CF and may require a more extended recovery period.

Therefore, members of the public (especially the abovementioned high-risk groups) are advised to seek medical advice promptly if they develop relevant symptoms, particularly a fever, sudden severe joint pain, and skin rash, after visiting areas affected by CF.

Since the beginning of 2025, and as of September 30, a total of 445,271 suspected and confirmed CF cases and 155 CF-related deaths have been reported in 40 countries/territories.

Cases have been reported in the Americas, Africa, Asia, and Europe. CF outbreaks currently occur in many countries worldwide.

From a disease prevention option, chikungunya vaccines have been approved in various countries, including the United States.

the South Carolina Department of Public Health (DPH) recently confirmed it is actively responding to a measles outbreak in the Upstate region.

As of October 21, 2025, DPH is reporting 23 cases of measles since early July, centered around Spartanburg County, home to over 320,000 people.

To date, all confirmed measles cases have been in unvaccinated individuals.

DPH wrote in a press release, "There has been a rise in measles cases in the Upstate this year, with most concentrated in Spartanburg County."

"Some cases are travel-related exposures or close contacts of known cases. Other cases have no identified source, suggesting that measles is circulating in the community and could spread further."

"We have seen measles spread quickly in unvaccinated households here in South Carolina."

"We also know that it can spread quickly in unvaccinated communities based on outbreaks in other states."

In response to the ongoing measles outbreak, DPH has activated its Mobile Health Unit to offer measles-mumps-rubella vaccine to unvaccinated individuals at no cost. 

A pertussis (whooping cough) outbreak has once again been reported in the Argentine Republic.

As of mid-October, data up to Epidemiological Week 41 confirm that the Argentine health ministry reported 333 cases of whooping cough in the country. The confirmed cases for the year are distributed across 17 jurisdictions.

The region with the highest number of cases is the Central Region, where 260 cases were reported, of which 167 correspond to the province of Buenos Aires and 50 to the Autonomous City of Buenos Aires.

The Southern Region follows, with 58 cases registered within the framework of the outbreak currently affecting the city of Ushuaia in Tierra del Fuego.

The highest cumulative incidence during the 2025 outbreak has been recorded in Tierra del Fuego, which is located in the southern area.

This number exceeds the confirmed cases reported for the same period in 2021, 2022, and 2023.

Given its high contagiousness, the Ministry of Health is currently working with provincial authorities to ensure timely care for people with acute respiratory illness symptoms and their close contacts, to limit the spread of the disease.

The Ministry says it is essential to keep in mind that vaccination is the primary prevention strategy and one of the most effective interventions for reducing morbidity and mortality in infants and other vulnerable groups.

Pertussis is included in Argentina's National Immunization Schedule.

As of October 21, 2025, the U.S. CDC states international travelers should check the vaccines and medicines list and visit their healthcare provider at least a month before visiting Argentina, a country with about 45 million residents, which is located in the southern area of South America.