Vaccine News

According to an analysis recently published by the U.S. Centers for Disease Control and Prevention (CDC), fewer infants were admitted to hospitals struggling to breathe from Respiratory Syncytial Virus (RSV) last season. 

This positive trend was announced in the MMWR (74(16);273–281) on May 8, 2025, following the approval of RSV vaccines and antibody treatments for the 2024-2025 season.

Data from the RSV-Associated Hospitalization Surveillance Network (RSV-NET) and New Vaccine Surveillance Network (NVSN) showed infants aged 0–7 months (eligible for protection with maternal vaccination or nirsevimab), 2024–25 RSV-associated hospitalization rates were lower compared with the 2018–20 pooled rates.

The most significant estimated rate reduction was observed among infants aged 0–2 months (RSV-NET: 52%, 95% CI = 49%–56%; NVSN: 45%, 95% CI = 32%–57%) and during peak hospitalization periods (December–February). 

In a sensitivity analysis of the NVSN surveillance site in Houston, Texas, where the RSV season began before vaccine and antibody treatments were available, the effect was even more pronounced, with a 71% drop in infant hospitalizations.

The findings suggest the importance of protecting infants born during the RSV season through either maternal vaccination during pregnancy or nirsevimab (Beyfortus) administration in the first week of life, ideally during the hospitalization for birth.

The latest provisional data published by the UK Health Security Agency (UKHSA) show an increase in travel-associated malaria cases in England, Wales, and Northern Ireland, exceeding the levels seen in recent years.

As of June 10, 2025, the UKHSA data indicate that imported malaria cases remain at concerning levels in the UK, despite a slight decrease in diagnoses, from 2,106 in 2023 to 1,812 in 2024.

Most cases were reported during peak summer travel months between July and October.

The World Health Organization's latest malaria report estimated 263 million malaria cases and 597,000 related fatalities worldwide in 2023.

The WHO African Region bears the heaviest burden of malaria disease, with Burkina Faso, Cameroon, Ethiopia, the Democratic Republic of the Congo, Ghana, Mali, Mozambique, Niger, Nigeria, Sudan, Uganda, and Tanzania being among the countries most affected.

Dr Diana Ayoola Mabayoje, co-founder of African Diaspora Malaria Initiative (ADMI), commented in a media release, 'Our focus is on community engagement and outreach, and we will be targeting African communities in London ahead of summer travel.'

Malaria is a potentially fatal disease, but it is almost entirely preventable when antimalarial tablets are taken correctly.

Furthermore, two malaria vaccines are now offered in specific countries, such as in Africa.

Dengue fever is endemic in most countries in Southeast Asia and continues to pose a significant public health threat in tropical regions, including Malaysia, Singapore, and Thailand. 

Since a recent Dengue fever outbreak began in Malaysia in late 2022, 13 states and three federal territories have been impacted.

According to the World Health Organization, Malaysia confirmed 122,423 Dengue cases and 117 related fatalities in 2024, a 17% increase from the number recorded in 2023.

Without widespread access to a Dengue prevention vaccine, the mosquito-transmitted disease continued to spread in Malaysia in 2025.

Recent data published by the Dengue For Community Portal indicate that Taman Mawar - Sendang was last week's Dengue hotspot, reporting 158 new cases.

Unlike Malaysia, Thailand recently launched a vaccination campaign to eliminate the disease burden on the population and the healthcare system. A large-scale study was launched in April 2025 in Nakhon Phanom province, involving 35,000 children.

Approved by the National Communicable Disease Committee, the clinical trial aims to assess the effectiveness of the QDENGA live-attenuated dengue vaccine, which has already received clearance from Thailand's Food and Drug Administration.

Local media reported on June 10, 2025, that Dr. Panumas Yanawetsakul, Director General of the Department of Disease Control, stated the trial would span three years, after which the vaccine could be added to Thailand's universal healthcare scheme.

If approved, Thailand would join over 30 countries that offer Takeda's QDENGA in 2025.

As of June 2025, QDENGA is not offered in the United States.

According to an update from the Global Polio Eradication Initiative (GPEI) on June 4, 2025, six countries reported additional polio cases last week.

The Islamic Republic of Pakistan, located in South Asia, reported a case of wild poliovirus type 1 (WPV1) from Gilgit-Baltistan, bringing its total number of cases to 11 in 2025.

Additionally, two WPV1-positive environmental samples were reported from Balochistan and Punjab, indicating the risk of additional cases being reported in 2025.

In 2024, 74 WPV1 cases were reported in Pakistan.

According to the European CDC, the last WPV infection in Europe was in 1998, and the World Health Organization declared the European Region polio-free in 2002. 

Five other countries reported circulating vaccine-derived poliovirus type 2 (cVDPV2) cases last week: Chad, Angola, Chad, Ethiopia, Niger, and Yemen.

Additionally, Papua New Guinea reported acute flaccid paralysis cases have been reported across 11 provinces, with 20 cases testing negative for poliovirus and 28 cases still under investigation, as of June 6, 2025.

Since polio is a vaccine-preventable disease, the ECDC published a guide for children and adults that focuses on strengthening the capacities of healthcare providers to better address concerns about vaccination and tackle obstacles to vaccination uptake.

In the United States, Polio vaccination has been part of the routine childhood immunization schedule for decades. Since 2000, the Inactivated polio vaccine (IPV) has been the only polio vaccine offered. In July 2022, a case of polio caused by VDPV2 in an unvaccinated individual from Rockland County, New York.

The U.S. CDC recommends that an IPV booster dose may be advisable when visiting a poliovirus endemic area in 2025.

While not every tick bite can pass the Lyme disease virus to a person, avoiding bites is the best way to prevent this severe disease in 2025. Since tick bites can occur year-round, they generally peak during the warmer months in the northeastern United States, between April and September.

However, this year has started differently.

According to new data posted by the U.S. CDC's Tick Bite Data Tracker, the number of emergency room visits related to a tick bite has been decreasing over the past month.

The CDC's data may not accurately reflect the actual spread of Lyme disease into the Midwest in 2025.

Last year, the Michigan Department of Health and Human Services confirmed Lyme disease was the most common tick-borne disease in Michigan. Cases in Michigan have increased by 168% over the last five years.

As a Lyme disease prevention update, the U.S. Food and Drug Administration has not yet approved a vaccine.

But an innovative Lyme disease vaccine candidate (VLA15) is progressing in late-stage clinical trials.

A multijurisdictional measles outbreak has occurred in Canada, beginning in New Brunswick in October 2024. This year, it has spread in Ontario (1,949), and related cases have been reported in Alberta, British Columbia, Manitoba, the Northwest Territories, Nova Scotia, Prince Edward Island, Quebec, and Saskatchewan.

Canada Health's Measles and Rubella Weekly Monitoring Report states that, of the 2,755 measles cases (2,429 confirmed, 326 probable) reported in 2025, 1,867 cases are linked to this outbreak as of June 2, 2025.

At the end of May 2025, only 244 new measles cases were reported in one week, indicating a continued decline of this outbreak.

The government says, 'If you're infected with the measles virus, you can spread it to others. This is possible from 4 days before the onset of the rash to 4 days after the rash begins. Isolate at home and call a health care provider immediately. They will advise you on what to do.'

As of June 8, 2025, measles vaccination services are offered throughout Canada.

According to a Case Report published by the Journal of Infection and Chemotherapy (Volume 31) in June 2025, Japanese encephalitis (JE) has emerged in a previously non-reported area in Japan, suggesting that the number of JE patients may be underestimated in Japan.

This report describes three cases of JE in a single hospital in Narita over three years.

These researchers suggest that physicians in Japan should consider JE as a differential diagnosis in 2025 when encountering cases of encephalitis or meningitis with unknown etiology during the warm season, even in areas where JE has not been previously reported.

This prefecture is located a few miles east of Tokyo, a city with over 35 million residents.

JE is an infection of the brain caused by the Japanese encephalitis virus, which is spread to people through the bite of an infected mosquito or close contact with livestock, such as birds, goats, and pigs.

In Japan, JE used to be endemic, and more than 1000 JE patients had been reported before the 1960s.

However, the introduction of the JE vaccine in 1954 and its widespread use in childhood vaccination from 1967 dramatically reduced the disease burden. As of 2022, only one case had been reported in Chiba and Ibaraki prefectures, respectively, in the past 10 years, and both cases occurred in areas famous for pig farming, far from Narita City.

As of June 5, 2025, the U.S. CDC recommends JE vaccination for specific people visiting Japan.

The CDC recommends vaccination for travelers who are moving to an area with JE, spend long periods in areas with JE present, or frequently travel to those areas in Japan.

JE vaccination is not recommended for travelers planning short-term trips to urban areas or those traveling to places with no clear JE season. 

When departing for Japan or any other JE outbreak area, such as Australia, Valneva SE's IXIARO® (JESPECT®) vaccine is commercially offered at travel clinics and pharmacies in 2025.