Coronavirus Breaking News

With the summer of 2025 cruise ship season getting underway, many passengers are seeking access to a norovirus preventive vaccine.

As of May 14, 2025, the U.S. CDC's Vessel Sanitation Program had reported 17 gastrointestinal (GI) illnesses on cruise ships this year, with over ten classified as norovirus outbreaks, and others still under investigation.

This CDC data compares with 18 GI outbreaks in all of 2024 and just 14 in 2023.

While norovirus vaccine research has been previously unsuccessful, one oral vaccine has published positive news.

Vaxart, Inc. recently announced the publication of complete data from a Phase 2b challenge study of its first-generation oral pill norovirus vaccine candidate. 

This study measured safety, efficacy against infection and symptomatic disease, as well as viral shedding.

Additionally, a machine learning analysis identified statistically significant correlates of protection, which will be incorporated into the development of Vaxart’s second-generation norovirus vaccine candidate.

“Challenge studies provide unique opportunities to identify correlates of protection that can be used to predict vaccine efficacy and support vaccine development,” said James F. Cummings, MD, Chief Medical Officer at Vaxart, in a press release.

“The application of machine learning approaches to the complete data from the Phase 2b challenge study of our first-generation oral pill norovirus vaccine candidate identified two such correlates, functional serum blocking antibody and fecal IgA."

"Evaluation of these endpoints will help inform our understanding and provide an early read on the potential efficacy profile of our second-generation norovirus vaccine candidate as it advances through clinical development."

The single-center, double-blinded Phase 2b challenge study enrolled 165 healthy adults, who were randomized 1:1 to receive Vaxart’s monovalent oral pill vaccine candidate targeting the norovirus GI.1 genotype or placebo. Four weeks after vaccination, subjects were challenged with GI.1 norovirus. The primary objective of the study was to determine the efficacy of the vaccine against norovirus infection and norovirus gastroenteritis (NVG) following gastrointestinal (GI) infection.1 NV challenge.

Secondary objectives were to assess the safety and tolerability of the vaccine candidate. The ability of the vaccine candidate to modify disease severity, the quantity and duration of norovirus shedding, and a set of immunogenicity parameters was also quantified. The primary efficacy endpoints were the proportion of participants showing evidence of NVG, a composite endpoint defined as meeting one or more definitions for acute gastroenteritis and a positive norovirus infection, and the norovirus infection itself.

Key findings from the study include the vaccine was immunogenic and protected against norovirus infection, with a 30% relative reduction for the vaccine group compared with placebo (p=0.003); The vaccine group had a lower incidence of norovirus gastroenteritis (21% relative reduction), but was not statistically different (p=0.178); The vaccine significantly increased serum IgA, IgG, norovirus-blocking antibodies, and antibody-secreting cells (p<0.001 for all endpoints). The vaccine stimulated mucosal-homing B cells and significantly increased norovirus-specific antibodies in saliva, nasal lining fluid, and the intestine.

Steven Lo, Chief Executive Officer of Vaxart, added, “The initiation of the Phase 1 clinical trial comparing our first- and second-generation norovirus vaccine candidates is a key step toward this important goal."

"The Phase 2 challenge study published today for our first-generation norovirus candidate supports our oral pill norovirus vaccine approach, and the preclinical data we have generated to date support our view that our second-generation candidate has the potential to provide improved immunogenicity and protection.”

As of May 30, 3035, the CDC has not recommended any norovirus vaccine.

During 2025, various measles outbreaks have been reported in North America. As of the end of May, the data from Canada and the United States have diverged.

In Canada, during week #20 (May 11 to 17, 2025), 354 new measles cases were reported. 

Throughout 2025, a total of 2,515 measles cases have been reported by nine Canadian jurisdictions: Alberta, British Columbia, Manitoba, the Northwest Territories, Nova Scotia, Ontario, Prince Edward Island, Quebec, and Saskatchewan. 

With Ontario reporting 1,848 cases, the vast majority of Canada's measles outbreak.

In the U.S., the Centers for Disease Control and Prevention (CDC) reported a total of 1,046 confirmed measles cases as of May 22, 2025, across 31 jurisdictions.

Of all states, Texas has been the unfortunate leader in 2025.

The Texas Department of State Health Services has reported 729 cases in West Texas and 24 other cases since late January 2025. The good news is that Texas has only reported one new measles case since May 23.

Globally, Ontario and Texas are not the only areas with measles outbreaks in 2025.

To notify international travelers of this ongoing health risk, the CDC reissued a Travel Health Advisory on May 28, 2025, identifying more than 50 countries that have reported measles cases.

The CDC recommends that international travelers be fully vaccinated against measles with the measles-mumps-rubella (MMR) vaccine, according to the CDC's measles vaccination recommendations for international travel. 

However, the CDC says, 'travelers unable to safely receive a measles-containing vaccine should talk to their clinician and consider postponing their trip.'

In the U.S., travel vaccine experts are staffed within many clinics and pharmacies to offer local vaccination recommendations.

Since early 2025, SARS-CoV-2 virus activity has been increasing globally, with the positivity rate reaching 11% in some countries. However, unlike in past years, activity is now very regional.

According to the World Health Organization (DON572) on May 28, 2025, this respiratory disease increase is primarily observed in countries in the Eastern Mediterranean, South-East Asia, and Western Pacific regions.  

This DON says recent increases in SARS-CoV-2 activity are broadly consistent with levels observed during the same period last year. But virus surveillance has been limited in 2025

Countries in the African Region, European Region, and the Region of the Americas are currently reporting low levels of SARS-CoV-2 activity with percent positivity from sentinel or systematic virological surveillance sites ranging from 2% to 3%. 

WHO advises all Member States to continue applying a risk-based, integrated approach to managing COVID-19, including vaccinations. Currently approved COVID-19 vaccines continue to protect against severe disease and death.

The WHO and its Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC) continue to regularly assess the impact of variants on the performance of COVID-19 vaccines to inform decisions on updates to vaccine composition.

In the latest recommendation published in mid-May 2025, the WHO TAG-COVAC advised that monovalent JN.1 or KP.2 remain appropriate COVID-19 vaccine antigens; monovalent LP.8.1 is a suitable alternative vaccine antigen.

An estimated 39.2 million individuals, across 90 reporting Member States, had received a dose in 2024. Uptake was notably higher among older adults, with coverage reaching 5.1% in the European Region and 3.6% in the Region of the Americas, compared to less than 0.5% in other regions.

In the United States, the COVID-19 vaccination policy was updated in May 2025.

Since the end of the recent pandemic, medical care has become a global industry. Research reveals that about 1.4 billion passengers are expected to fly in 2025.

The Medical Value Travel (MVT) population, which travels to countries seeking healthcare services, is experiencing rapid growth worldwide.

According to the Federation of Indian Chambers of Commerce (FICCI), the global MVT market size was valued at $115.6 billion in 2022 and is expected to reach approximately $286.1 billion by 2030.

In India, the MVT is expected to grow at a CAGR of 21.1% from 2020 to 2027 and is projected to reach $13 billion by 2026.

Bangladesh, Iraq, Maldives, Afghanistan, Oman, Yemen, Sudan, Kenya, Nigeria, and Tanzania account for about 88% of the total international patients visiting India.

The leading health services offered in India are for heart surgery, knee transplant, cosmetic surgery and dental care as the cost of treatment in India is considered to be the lowest in Asia.

The FICCI video stated on May 26, 2025, 'Realizing the increasing importance of global medical value travel and its significance to the Indian medical industry.'

Recent research indicates that tens of millions of people are not adequately vaccinated before visiting disease-endemic countries.

For example, in Europe, over 4% of returning international travelers who recently displayed symptoms may be infected with a mosquito-transmitted disease, such as chikungunya, dengue, or Zika.

When departing abroad in 2025, the U.S. CDC recommends that travelers consult with a travel vaccine expert about immunization options at least one month before departure.

According to a recent blood donor study, about 37% of the residents of the Republic of Paraguay may be infected with the Chikungunya virus.

A research article published in the journal Medical Virology on May 13, 2025, stated that serum samples from 546 blood donors across seven regional districts and Asunción were collected from March to May 2023.

Anti-CHIKV IgG prevalence was 37.2%, with men showing a seroprevalence nearly 10% higher than women, but no significant age-related differences were observed.

Regional variation in CHIKV seroprevalence was not substantial.

In conclusion, this study suggests a high seroprevalence of CHIKV in Paraguayan blood donors, with the notable CHIKV prevalence underscoring the effects of recent outbreaks.

As of May 26, 2025, the U.S. CDC says there has been evidence of CHIKV transmission in Paraguay within the last 5 years.

During 2024, about 2.2 million people visited this South American country. 

Furthermore, the CDC says certain travelers visiting Paraguay may be considered for Chikungunya vaccination. CHIKV vaccines are offered at travel clinics and pharmacies in the United States.

The Republic of Singapore's Ministry of Health (MOH) and Communicable Diseases Agency (CDA) recently updated the vaccination requirements for all pilgrims travelling to Saudi Arabia for Haj or Umrah pilgrimages, in consultation with Majlis Ugama Islam Singapura (MUIS).

This vaccination update, published on May 8, 2025, safeguards pilgrims' health throughout their journey and better protects them from infections while overseas.

Singapore pilgrims travelling to Saudi Arabia for the Haj pilgrimage in June 2025 also need to be vaccinated for influenza and COVID-19 before travel, in addition to meningococcal vaccination. Pilgrims are to ensure that: 

Meningococcal vaccination: Pilgrims must complete their meningococcal vaccination at least 10 days before departure and provide proof of immunization. 

COVID-19 vaccination: Pilgrims must show proof of either a single dose of the updated vaccine for the 2024-2025 season, completion of the primary vaccination series, or laboratory-confirmed recovery from a COVID-19 infection during 2024. 

Influenza vaccination: Pilgrims must receive their influenza vaccination within 12 months before their travel date and provide proof of immunization.

In addition, the MOH and CDA recommend that pilgrims ensure they are updated with other nationally recommended vaccinations listed in the National Adult Immunisation Schedule and National Childhood Immunisation Schedule.

For example, elderly and medically vulnerable pilgrims should take the pneumococcal vaccine before their trip. For more information about nationally recommended vaccinations and available subsidies, please visit the CDA website.

Hajj is an annual Islamic pilgrimage to Mecca, Saudi Arabia, and Umrah is a pilgrimage to Mecca, located in the Hejazi region of Saudi Arabia.

According to a recent research program by the  UK Health Security Agency (UKHSA) and the Animal and Plant Health Agency, West Nile Virus (WNV) genetic material has been detected in mosquitoes in Britain for the first time.

This area is located about 70 miles east of Manchester, UK.

These researchers stated that UKHSA collected Aedes vexans mosquitoes from wetlands on the River Idle near Gamston (Retford), Nottinghamshire, in July 2023.

As of May 21, 2025, the UKHSA has assessed the risk to the general public as very low, but is advising healthcare professionals so that patients with encephalitis of unknown cause can be tested as a precaution.

WNV is usually found in birds, and typically circulates through bird-biting mosquitoes, which can transmit the virus to humans or horses.

While rare in the United Kingdom (UK), WNV is endemic in various regions across the globe, including  Europe, Africa, the Middle East, West and Central Asia, and North America, as well as South America, Australia, and the USA. 

Since 2000, seven travel-associated cases have occurred in the UK.

In 2024, 1,466 WNV cases were confirmed in 49 states in the USA, led by Texas with 176 cases.

Dr Jolyon Medlock, Head of Medical Entomology and Zoonoses Ecology at UKHSA, added in a media release, "Mosquitoes in the UK are also commonly found in wet woodland areas and various aquatic habitats, including ponds, ditches, marshes, and even garden water butts or cisterns."

"To avoid being bitten by a mosquito in these areas, wear long-sleeved clothing and trousers to cover your arms and legs, use insect repellent on your skin,  close windows and doors whenever possible, or use blinds or screens."

Additionally, there are no approved WNV vaccines for people in 2025.

However, current human clinical studies include vaccine candidates such as two live attenuated chimeric, one DNA, one recombinant subunit, and two inactivated whole-virus vaccines.