Coronavirus Breaking News

With five norovirus outbreaks aboard cruise ships already reported by the U.S. CDC's Vessel Sanitation Program in 2025, there continues to be significant interest in accessing a preventive vaccine for this 'stomach virus.'

Over the past few years, viable norovirus vaccine candidates have been unsuccessful in preventing this highly contagious virus that causes acute gastroenteritis and can lead to substantial morbidity in older adults.

However, on March 5, 2025, Vaxart, Inc. announced that complete data from the Phase 1b trial of its first-generation oral pill norovirus vaccine candidate have been published in Science Translational Medicine. The data show strong and durable antibody responses and induction of norovirus-specific antibody and T cell responses.

“A key finding of this study evaluating our first-generation oral pill norovirus vaccine candidate in elderly individuals was that the antibody and serum responses observed in these participants were robust and durable, and a cross-study analysis suggested that the observed antibody and cellular responses were independent of age. These findings are encouraging given that older adults have an increased risk of norovirus-related morbidity and may have less robust immune responses following vaccination than younger individuals,” said James F. Cummings, MD, Chief Medical Officer at Vaxart, in a press release.

“Another key result was that an orally-administered vaccine can generate potent antibody responses in mucosal tissues outside the gastrointestinal tract, which could have important implications for use of our vaccine platform for norovirus and other indications.”

In January 2025, Vaxart announced that the next step in its norovirus program would be a Phase 1 clinical trial evaluating its second-generation oral norovirus vaccine constructs head-to-head against its first-generation constructs. This trial is expected to initiate in the first half of 2025.

While this is a good update, it means cruise ship passengers and crew may not have access to a norovirus vaccine this year.

The Mayotte Regional Health Agency announced today that it has detected its first case of imported Chikungunya on the main island off the east coast of Africa.

On March 5, 2025, a Mamoudzou resident returned from visiting La Reunion Island, another of France's overseas departments. These departments are separated by the island of Madagascar and the Mozambique Channel. 

Following this identification, the ARS of Mayotte immediately implemented vector control actions to identify larval breeding sites around the person's home. Local health professionals and emergency services have been informed of the situation.

No indigenous case has been reported in Mayotte to date. 

Generally, a single, travel-related Chikungunya case does not generate significant actions.

However, since late August 2024, La Reunion has been facing a Chikungunya epidemic, with 3,390 cases recorded.

Furthermore, an apparent Chikungunya epidemic has increased in late February and early March 2025. During one week, 1,300 new cases of Chikungunya were confirmed.

In mainland France, 25 travel-related cases were reported in 2024. And, for the first time, Ile de France (Paris) reported a locally acquired Chikungunya case.

The World Health Organization says Chikungunya transmissions have occurred frequently in about 110 countries.

So far this year, 49,491 Chikungunya cases and two related fatalities have been confirmed in the Region of the Americas. In 2024, over 400,000 cases were confirmed.

Most people infected with the Chikungunya virus develop some symptoms 3–7 days after a bite by an infected mosquito. People at risk for more severe disease include newborns infected around the time of birth, older adults, and people with medical conditions.

Chikungunya has recently become a vaccine-preventable disease.

Since late 2023, an innovative vaccine has been available in various countries, including the United States. The U.S. CDC recommends Valneva SE's IXCHIQ® vaccine for certain international travelers in 2025. This vaccine is often offered at travel clinics and pharmacies,

According to a recent International Visitors Survey, the Kingdom of Tonga has become a preferred destination in Polynesia. Visitor satisfaction was highly ranked, with the friendly local population, water-based attractions, and cultural activities ranking very well.

However, a mosquito-transmitted disease may curtail tourism.

Tonga's government today reported a significant increase in dengue fever cases with 30 additional new cases.

As of March 5, 2025, there have been 129 dengue cases this year.

With 45 inhabited islands, the majority of dengue cases were from Vava'u (63), the rest from Tongatapu (47) and 'Eua (19).

Tonga's Ministry of Health (MOH) says dengue Virus Type 2 (DENV-2) is responsible for the current outbreak.

This dengue outbreak subtype is different from DEN-3, which is the dominant case in the region of the Americas, including in Florida and Puerto Rica.

The MOH recommends that residents and visitors wear appropriate clothing to minimize mosquito bites, use mosquito nets and repellents such as lotion and spray, and if you are sick, watch out for severe symptoms and seek medical attention immediately.

While the U.S. CDC does not recommend getting an approved dengue vaccine, it does support various routine and travel vaccines before visiting Tonga in 2025.

The state of Texas has been reporting a spike in measles cases in 2025, including some in vaccinated children.

The Texas Department of State Health Services (DSHS) initially reported two measles cases in Harris County, which includes the city of Houston, in January 2025.

Since then, DSHS has confirmed an ongoing measles outbreak in the South Plains. As of March 4, 2025, 159 cases have been identified. There has been one fatality in a school-aged child who lived in the outbreak area. The child was not vaccinated and had no known underlying conditions.

Another measles case was recently reported in Travis County by the Austin Health Department.

The DSHS's investigation into the vaccination status is ongoing. So far, 5 cases have been confirmed as vaccinated with one dose. In 74 cases, the vaccination status is classified as unknown.

DSHS wrote, 'A dose of MMR is given to unvaccinated people within 72 hours of their exposure to the measles to lessen the severity of the illness if they get sick from the virus.'

'We are investigating whether any of these cases received their MMR dose after (virus) exposure.'

'Due to the highly contagious nature of this disease, additional cases are likely to occur in the outbreak area and the surrounding communities,' added DSHS.

Last year, 285 measles cases were reported in the U.S. Minnesota (70) and Illinois (67) were the leaders in confirming measles outbreaks.

Most of the measles cases in 2024 were traced to unvaccinated international travelers.

Currently, the U.S. CDC maintains a Level 1 Travel Health Advisory that identifies 57 countries reporting measles cases.

The CDC and DSHS strongly encourage most people to get two doses of a MMR vaccine, available at clinics and pharmacies in the United States in 2025.

Measles vaccination programs began in the United States in 1963. Since then, the MMR vaccine has been found to be very safe and about 95% effective.

The U.S. FDA has approved the M-M-R®II, ProQuad®, and Priorix vaccines to prevent measles. On November 18, 2022, the CDC stated that the Priorx and M-M-R II® vaccines are considered fully interchangeable.

While the mpox Clade 2 outbreak has spread globally since May 2022, Clade 1 cases have been limited to travel-related detections in most countries.

According to the South Africa's Department of Health's announcement on February 27, 2025, the country has recorded three laboratory-confirmed cases of mpox Clade 1 in three provinces, such as Gauteng. 

Gauteng province contains the country's largest city, Johannesburg, home to about 16 million people.

This news increases the cumulative number of positive cases from 25 to 28, including three deaths.

The DOH wrote in a press release, 'There is no need for the public to panic, but people are urged to remain cautious of how mpox spreads and to seek help when faced with symptoms of mpox.'

'The risk of wider transmission remains low in South Africa, but anyone can contract mpox regardless of age, gender, sexual orientation and race.'

Mpox has become a vaccine-preventable disease.

However, South Africa has a limited stock of a mpox-specific vaccine for the treatment of patients who experience severe health complications as a result of this sexually transmitted disease.

As of March 4, 2025, about four mpox vaccines have been used worldwide.

Globally, mpox continues to be a Public Health Emergency of International Concern and a Public Health Emergency of Continental Security, as per the declarations by both the World Health Organization and Africa Centres for Disease Control and Prevention in August 2024.

The mpox outbreak is ongoing in thirteen out of 22 countries in Africa, with Uganda and the Democratic Republic of Congo currently reporting the highest number of cases.

In the United States, most Clade 1 mpox cases have been travel-related.

As the 2024-2025 flu season winds down in the United States, the U.S. CDC recently reported positive news regarding this year's influenza vaccine effectiveness (VE).

On February 27, 2025, the CDC announced that the interim 2024–2025 seasonal influenza VE estimates among children and adolescents were 32%, 59%, and 60% in outpatient settings and 63% and 78% against influenza-associated hospitalization.

Among adults, VE was 36% and 54% in outpatient settings and 41% and 55% against influenza-associated hospitalization.

The CDC wrote that this data indicated 'vaccination with the 2024–2025 influenza vaccine reduced the risk for influenza-associated outpatient visits and hospitalization.'

Unfortunately, twelve pediatric deaths associated with seasonal influenza virus infection were reported last week, bringing the 2024-2025 season total to 98 pediatric deaths.

Last flu season, 207 children died from influenza infections.

These CDC findings support the recommendation that all eligible persons aged ≥ over six months receive an annual influenza vaccination.

From an availability perspective, with over 100 million vaccines distributed this season, flu shots should be offered at clinics and pharmacies as long as influenza viruses are circulating.

While the United States only reported 199 Chikungunya fever cases last year, recent research indicates this low number may be related to under-testing.

The U.S. Centers for Disease Control and Prevention (CDC) says that among the cases reported in 2024, a higher-than-expected number of Chikungunya cases occurred among returning travelers from India, where the National Center for Vector-Borne Diseases Control in India reported 192,343 CHIKV cases in 2024.

Although not listed as a hemorrhagic fever virus, the Chikungunya virus (CHIKV) can be easily confused with more well-known diseases, such as dengue or yellow fever.

According to the CDC, a Chikungunya diagnosis should be made by nucleic acid testing during the acute phase of infection or by serologic testing after the first week of illness.

Additionally, a positive CHIKV-specific IgM antibody test result should be confirmed by neutralizing antibody testing at a state public health laboratory or

Therefore, the CDC says healthcare providers should consider CHIKV infection in patients with acute onset of fever and polyarthralgia for appropriate clinical management. Providers are also encouraged to report suspected Chikungunya cases to health departments to facilitate diagnosis and mitigate the risk of local transmission.

These CDC recommendations are challenging as most CHIKV infections are related to international travelers visiting over 100 countries in Africa, Asia, and the Americas. 

Furthermore, Pune's National Institute of Virology has indicated that CHIKV variants are causing more cases and lingering symptoms in 2024. A  study published on October 19, 2024, identified Chikungunya's "Indian Ocean lineage" as the primary cause of the recent surge in cases and lingering symptoms.

This novel CHIKV lineage, first identified in 2006, has also spread globally.

These experts have determined that the incidence of post-chikungunya chronic rheumatism and fatigue and the impact on quality of life and chronic fatigue in adults seven years after infections were significant.

To alert travelers of this health risk, the CDC updated its Level 2 Travel Health Advisory regarding outbreaks in various Indian states, such as Maharashtra and Telangana. These areas are very popular destinations for international travelers.

In 2025, the CDC recommends travelers to Chikungunya outbreak areas speak with a travel vaccine expert about immunization options since the U.S. FDA has approved one effective vaccine commercially offered at clinics and pharmacies.

A more straightforward and less expensive CDC recommendation to reduce Chikungunya disease cases this year is to avoid mosquito bites when traveling abroad.