Vaccine News

Argentine health authorities recently announced the country's first locally acquired case of mpox clade Ib. This development in Buenos Aires raises concerns about the potential for community transmission of this variant in South America.

The emergence of locally acquired clade Ib in Argentina underscores the virus's ability to establish transmission chains through sexual networks involving international travelers.

Buenos Aires, a major South American tourism hub, welcomed about 1.5 million foreign visitors last year.

The case, announced in report #9 on March 16, 2026, involves a man living in Buenos Aires who has no recent international travel history but reported sexual contact with multiple partners, including travelers, before the onset of symptoms. The patient is currently receiving outpatient treatment and is recovering. Contact tracing has begun, and there are recommendations for 21 days of follow-up monitoring.

Argentina's Ministry of Health has characterized clade Ib as being more severe and contagious than previous strains. They are urging health authorities to strengthen surveillance, ensure proper isolation until lesions have scabbed over, and provide healthcare workers with appropriate personal protective equipment.

Mpox first gained global attention in May 2022, primarily due to clade IIb of the virus. That outbreak resulted in over 100,000 confirmed cases worldwide across 122 countries, mostly transmitted sexually among men who have sex with men. Clade Ib differs from the milder clade IIb in terms of transmissibility.

In Argentina alone, approximately 1,129 confirmed cases and two deaths were reported between 2022 and early 2023. As of 2026, eight countries in the Americas, including Argentina, have reported a total of 172 mpox cases, with no deaths recorded to date.

As of March 20, 2026, effective mpox vaccines (JYNNEOS) are generally available in most countries.

The Department of State Health Services (DSHS) has launched a new sterilization program for dogs and cats to maximize the impact of sterilization across both urban and rural communities in Texas. 

DHSH confirmed on March 19, 2026, that the Texas Spay and Neuter Program has received $13 million from the legislature to fund this initiative for two years. Organizations selected for the program must employ or subcontract with a veterinarian who has significant spay-and-neuter experience.

Operating through 2026-2027, this pilot program is designed to protect human health by reducing the number of dogs and cats at risk of unplanned breeding, which can lead to the transmission of infectious diseases such as rabies. 

At least 33 confirmed animal rabies cases were reported by mid-March 2026.

From a local perspective, the most affected area in Texas was Travis County (Austin), with 68 cases in 2024, and patterns suggest a similar or higher number of cases in 2025.

From a disease prevention option for people, various clinics and pharmacies in Texas offer rabies vaccination services in 2026.

In addition to mitigating health risks for humans, spaying and neutering can also reduce the risk of cancer and other diseases in these animals. Research indicates that spayed and neutered cats and dogs tend to live longer on average.

For more information about the program, you can visit the Texas Spay and Neuter Program website.

Additionally, DSHS funds the Texas Animal Friendly Program, which assists communities in providing low-cost spay-and-neuter surgeries through the sale of custom Texas license plates that promote animal friendliness.

UK health officials today confirmed that they are investigating a concerning outbreak of invasive meningococcal disease in the Canterbury area of Kent, located in southeast England.

This outbreak involves invasive meningococcal disease, a serious bacterial infection that can lead to meningitis and septicaemia.

The UK Health Security Agency (UKHSA) reported that as of March 17, 2026, there have been 15 epidemiologically linked cases, including two fatalities.

Four of the cases have been laboratory-confirmed as group B meningococcal disease (MenB), which has been responsible for the majority of such infections in the UK in recent years. The remaining cases are still under investigation. Several affected individuals are students and are currently in serious condition in the hospital.

Close contacts of the confirmed cases are being traced and will be offered precautionary antibiotics to help limit the spread of the disease.

The UKHSA has linked many of the cases to social venues and networks in Canterbury, with reports suggesting that a significant number of infections can be traced back to visits to Club Chemistry nightclub between March 5 and 7, 2026.

The UKHSA emphasizes that there is currently no evidence of spread beyond the Kent area, and efforts are focused on containment.

Symptoms of meningococcal disease can develop quickly and may include fever, headache, stiff neck, vomiting, sensitivity to light, a non-blanching rash (which does not fade under pressure), and confusion. Authorities urge anyone experiencing these signs—especially young people and students—to seek urgent medical attention, as early treatment is critical.

Although meningococcal disease remains rare overall, this cluster highlights the ongoing risks among adolescents and young adults in close-contact settings like universities, says the UKHSA.

In response to this outbreak, which officials describe as "unprecedented" and "very unusual," a targeted vaccination program using the MenB vaccine will be implemented in the coming days for students living in halls at the University of Kent. Since 2015, the MenB vaccine has been available in the UK.

Trish Mannes, UKHSA Regional Deputy Director for the South East, commented in a press release, "Once again we remind anyone who visited Club Chemistry between 5 and 7 March to come forward for preventative antibiotic treatment as a precaution, as well as those offered antibiotics at the university."

As of March 17, 2026, the U.S. CDC has not issued a Travel Health Notice regarding this disease outbreak in the UK, nor has it issued vaccination recommendations.

In the U.S., the Bexsero® (MenB-4C) vaccine is available at clinics and pharmacies.

Health authorities in Venezuela are intensifying their efforts to combat a persistent yellow fever outbreak that began in 2025 and has continued into 2026.

As of late February 2026, Venezuelan health officials have confirmed 36 laboratory-verified human cases since the outbreak began, with at least six additional cases reported in the first seven weeks of 2026 alone, including one death.

According to recent reports from the Pan American Health Organization (PAHO) and Venezuelan officials, the outbreak has affected 14 states, marking a significant geographic expansion compared to previous localized incidents.

These confirmed cases have been reported across a wide area of the country. New areas affected include states such as Aragua, Barinas, Lara, and Portuguesa, which were not traditionally considered high-risk zones. This change has raised concerns about shifting transmission patterns, potentially influenced by environmental factors, reduced vaccination coverage in some regions, and population movements.

Venezuela's outbreak occurs amid broader regional challenges in South America, where 346 confirmed cases and 143 deaths were reported in 2025 across seven countries, such as Bolivia, Colombia, and Peru.

The PAHO says recent regional reports indicate that the case fatality rate hovers around 40-44%, highlighting the virus's lethality among those who develop serious illness.

In response, Venezuela's Ministry of People's Power for Health has launched a nationwide emergency vaccination drive using Stamaril (YF-VAX). Health Minister Nuramy Gutiérrez emphasized that a single dose of the yellow fever vaccine provides lifelong immunity.

As of March 16, 2026, the U.S. Centers for Disease Control and Prevention (CDC) maintains a Level 2 - Practice Enhanced Precautions travel notice for yellow fever in Venezuela. They advise travelers to get vaccinated at least 10 days before visiting at-risk areas, especially those located below approximately 2,300 meters (7,550 feet) in elevation.

The CDC advises travelers planning to visit Venezuela or other outbreak areas in 2026 to consult a healthcare provider or travel vaccine clinic well in advance, as not all facilities stock the yellow fever vaccine.

In preparation for the next Respiratory Syncytial Virus (RSV) season, which generally begins in Florida, the U.S. Food and Drug Administration (FDA) recently expanded the age range for Arexvy, an approved vaccine.

This GSK vaccine now includes adults aged 18 to 49 who are at increased risk for lower respiratory tract disease (LRTD) from RSV.

Previously, this vaccine was approved for most adults aged 60 and older, as well as those aged 50 to 59 with underlying health conditions who face heightened risks. It's important to note that this vaccine isn't designed for use by pregnant individuals.

Sanjay Gurunathan, GSK's Head of Vaccines and Infectious Diseases Research and Development, expressed optimism about the expansion in a press release issued on March 13, 2026, saying, "This age extension addresses a significant need for adults in the U.S. who are at higher risk for severe RSV disease due to certain medical conditions."

"It also helps alleviate pressure on our healthcare system."

GSK stated it is advancing its regulatory submissions globally to expand the availability of its RSV vaccine and support long-term growth goals.

According to the U.S. CDC, RSV can have a notable impact on younger adults as well, with the annual estimates showing around 17,000 hospitalizations, 277,000 visits to emergency departments, and a staggering 1.97 million outpatient visits among those aged 18 to 49.

As of February 22, 2026, the CDC reported that 43.2% of adults aged 75 years and older and 32.8% of adults aged 50─74 years with a high-risk condition for RSV reported having ever received an RSV vaccine.

RSV vaccines are available throughout the USA at various clinics and pharmacies.

With measles outbreaks accelerating in various states in March 2026, Florida's west coast continues as one of the unfortunate market leaders.

According to the Florida Department of Health's Reportable Diseases Frequency Report, the state has recorded 132 measles cases statewide so far in 2026, with Collier County accounting for the majority of infections.

Located southeast of Fort Myers and east of Naples, Ave Maria University's most recent health update as of March 16, 2026, notes that the Department of Health's website reported 93 confirmed and probable cases in Collier County through the end of February.

The university also states that there are currently zero nurse-assessed confirmed active cases on campus.

School officials emphasize that the vast majority of the Ave Maria community is vaccinated with the MMR vaccine.

Additionally, one confirmed case has been reported at the nearby Donahue Academy, a K-12 private school adjacent to Ave Maria University, indicating some community spread beyond the campus.

Florida DOH-Collier continues to collaborate with Ave Maria University to provide on-campus resources, including pre- and post-exposure guidance and MMR vaccinations at its Naples and Immokalee sites. The department urges anyone who may have been exposed or who is unvaccinated and eligible to seek preventive options promptly. 

Florida residents with concerns about potential exposure or vaccination status are encouraged to contact DOH-Collier or visit their local health department for assistance.

Furthermore, Florida continues to report travel-related and locally acquired mosquito-transmitted cases of chikungunya, dengue, and malaria in 2025 and early 2026.

The Centre for Health Protection (CHP) of the Department of Health announced today that it is investigating a cluster of 24 hepatitis A infections linked by identical viral genetic sequences, detected in Hong Kong between September 2025 and February 2026.

These cases primarily affect men, a significant portion of whom identify as men who have sex with men (MSM). Epidemiological investigations found no common residences or restaurants among the patients, leading authorities to note that male-to-male sexual contact cannot be ruled out as a transmission factor.

Dr. Edwin Tsui, Controller of the CHP, emphasized in a media release on March 11, 2026, that hepatitis A outbreaks among MSM populations have occurred globally in the past, including a similar transmission chain in Hong Kong from 2015 to 2017, which was controlled through targeted vaccination.

To curb the spread of this infection, the CHP urges high-risk groups, particularly MSM, to receive vaccinations with two doses of the hepatitis A vaccine. In response to the current cluster, the CHP will begin offering two free doses of the vaccine to eligible MSM residents of Hong Kong starting March 12, 2026.

Epidemic hepatitis A is primarily spread through the ingestion of contaminated food or water, or via contaminated hands before eating. However, it can also be transmitted through high-risk sexual contact. Symptoms, such as fever, fatigue, abdominal pain, nausea, diarrhea, and jaundice, typically appear 14 to 50 days after infection due to the virus's long incubation period.

For international travelers departing from the United States for Hong Kong, the CDC recommends that unvaccinated travelers also receive the Hepatitis A vaccine. And travelers allergic to a vaccine component should receive a single dose of immune globulin, which provides effective protection for up to 2 months, depending on the dosage given.

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

Recently, Hong Kong has reported increased risks of chikungunya.

The CDC also recommends various routine and travel vaccinations before visiting Hong Kong in 2026.