Coronavirus Breaking News

With nine reported pediatric fatalities related to influenza this season, many are questioning whether the updated vaccines provide adequate disease protection.

A new preprint study from researchers at the University of Pennsylvania (UPenn) offers encouraging insights into the ongoing 2025-2026 influenza season, which has been dominated by a drifted variant of the H3N2 virus known as subclade K.

The study, posted on medRxiv on January 6, 2026, examined blood samples from vaccinated individuals to assess how well the current seasonal flu vaccine triggers antibodies against this emerging strain.

Subclade K, characterized by several key substitutions in the hemagglutinin (HA) protein—including mutations like K2N, S144N, N158D, and others, which emerged late in 2025- was not included in the Northern Hemisphere vaccine formulation.

These UPenn researchers found that while subclade K viruses are antigenically advanced compared to the vaccine strain, the 2025-2026 vaccine still elicited robust antibody responses in many participants.

Before vaccination, only about 11% of individuals had neutralizing antibodies against subclade K.

After receiving the flu shot, this figure rose to around 39%.

Lead researcher Scott Hensley, a professor of microbiology at the UPenn, described the results as "unexpected good news."

The findings suggest that the vaccine is likely to provide meaningful protection against infections caused by subclade K, particularly against severe outcomes such as hospitalization.

This news comes amid a challenging flu season, with subclade K driving the majority of cases across the U.S. and globally.

U.s. Centers for Disease Control and Prevention (CDC) data for Week 52 indicate H3N2 accounts for nearly all influenza activity so far, with subclade K comprising over 90% of characterized H3N2 viruses.

Vaccine experts at the CDC emphasize that vaccination remains the best tool available, even against mismatched strains. Furthermore, there is an ample supply of flu shots offered at clinics and pharmacies in 2026

This preprint has not yet undergone peer review, but preliminary data align with observations from public health agencies monitoring the season.

The United Kingdom recently launched its routine childhood vaccination program against chickenpox (varicella).

Effective from January 1, 2026, this program introduces a combined measles, mumps, rubella, and varicella (MMRV) vaccine into the national immunization schedule.

According to the UK Health Security Agency article, this program is aimed at young children. It addresses a disease that affects hundreds of thousands each year and can lead to severe complications.

The vaccination program is offering two doses of the MMRV vaccine at 12 months and 18 months for those born on or after January 1, 2025.

The UK program also provides MMRV doses to slightly older cohorts, including a catch-up initiative running from November 2026 to March 2028 for children aged 3 years and 4 months to under 6 years who do not have complete protection.

The UK's delay in adopting universal chickenpox vaccination was based on concerns that reducing natural infections could weaken immune boosting in adults, potentially leading to an increase in shingles (herpes zoster) cases.

However, studies indicate that the live attenuated vaccine does not increase the risk of shingles.

The December 2025 article stated that even if your child has already had chickenpox, there are no safety concerns about getting the MMRV vaccine. You'll usually be contacted by your GP practice when your child is due for a routine vaccination, such as MMRV.

As the Australian Open 2026 kicks off at Melbourne Park on January 18, 2026, tennis fans and travelers can expect a return to everyday experiences, with no vaccination requirements for players, staff, or spectators.

As of January 6, 2026, this marks a significant shift from the 2022 tournament, which saw unvaccinated tennis player Novak Djokovic, one of the best, detained upon arrival and ultimately deported after his visa was canceled twice.

In 2022, Tennis Australia and the Victorian government required complete vaccination for all participants, allowing only limited medical exemptions for tennis players.

Djokovic had received an exemption based on a recent COVID-19 infection, but upon arriving in Melbourne, federal border enforcement deemed his documentation insufficient. After legal battles, he was deported on public health grounds, missing the event he had dominated with 10 titles.

Australia ended its vaccine requirements for international travelers in 2022, allowing Djokovic to return in 2023, where he claimed his 10th title.

As Djokovic seeks to win an 11th Melbourne crown—potentially his 25th Grand Slam overall—the 2026 event highlights how far tennis has come from the disruptions of 2022.

For the 2026 tournament, entry lists and official guidelines confirm that there will be no vaccination or testing mandates.

This is positive news for travelers as the Australian Open 2025 set an attendance record with about 1.2 million tennis fans visiting Melbourne Park.

Travelers are advised to consult official sources, such as the Australian Open website or government travel advisories, for the latest visa and health information.

For health-conscious tennis fans, the priority now is sun protection and hydration amid Melbourne's summer heat, rather than proof of vaccination.

The U.S. CDC currently recommends various routine and travel vaccinations before visiting Australia in 2026. These vaccines include measles and Japanese encephalitis when visiting the Murray River and the Outer Torres Strait Islands area.

As the world tennis season progresses in 2026, vaccination recommendations could be issued for those visiting France (chikungunya) or Miami, Florida (dengue)

The Republic of Colombia Ministry of Health recently posted on Facebook that it has seen a rise in yellow fever cases over the past two years.

From 2024 to January 4, 2026, Colombian officials reported 142 confirmed cases. This includes 63 deaths.

The mosquito-transmitted disease has been detected in ten departments, each with at least one death from yellow fever. These are Caldas, Caquetá, Cauca, Guaviare, Huila, Meta, Nariño, Putumayo, Tolima, and Vaupés.

While some of these yellow fever cases have occurred in forest areas, others have been reported near Bogotá, the capital city and a tourist destination.

Over the last few years, Tolima, located west of Bogota, has been the most affected area, often accounting for over 80% of yellow fever cases.

According to the World Health Organization and the U.S. Centers for Disease Control and Prevention, the yellow fever vaccine is among the most effective available. It is a live, attenuated vaccine that provides lifelong protection with a single dose for most people.

No booster doses are routinely needed. However, as of January 5, 2026, travel vaccine experts are available to provide insights on yellow fever immunization.

From a security perspective, the United Kingdom (UK) updated its travel advice on January 5, 2026, advising against all but essential travel to parts of Colombia, such as the Colombia-Venezuela border and northern Colombia.

The UK wrote that if you choose to travel to Colombia in 2026, research your destinations and get appropriate insurance. 

The Zika virus, once a major global health emergency, continues to circulate in the Americas, with the Pan American Health Organization (PAHO) confirming local transmission in 52 countries and territories since 2015.

While case numbers have fluctuated in recent years, the Federative Republic of Brazil remains the epicenter, historically reporting the highest number of confirmed cases in the Americas region.

Recent data highlight Brazil's ongoing battle with the mosquito-borne illness.

Brazil recorded 1,801 confirmed Zika cases, maintaining its lead in the Americas.

As of January 2, 2025, PAHO data indicate that Brazil has significantly reduced its number of confirmed Zika cases, with 2,067 cases reported in 2024 and 3,997 in 2023.

Many Zika outbreaks are concentrated in major Brazilian cities, including Rio de Janeiro, a metropolis of millions and a top destination for international travelers. As the city gears up for Carnaval 2026, scheduled from February 13 to 21, concerns about mosquito-borne diseases linger.

PAHO emphasizes that most Zika infections are mild or asymptomatic, but the virus poses serious risks to pregnant women, potentially causing congenital Zika syndrome in newborns. Travelers, especially those planning pregnancies, are advised to take precautions.

With no locally acquired Zika cases in the continental U.S. since 2019, the U.S. Centers for Disease Control and Prevention (CDC) Yellow Book states that international travelers with suspected Zika infection should be tested with real-time polymerase chain reaction or an NS1 antigen test.

This CDC advice is being followed in Hawai'i.

The Hawaiʻi Department of Health announced on May 27, 2025, that it is investigating two travel-related Zika cases.

And in U.S. territories, the CDC says Zika-spreading mosquitoes are found throughout Puerto Rico, where the Department of Health reported 16 cases in 2024, down from 43 in 2023.

From a disease prevention perspective, the CDC says no Zika vaccine candidate has been approved.

However, clinical trials are active in 2026.

Japan has experienced a dramatic resurgence of syphilis since 2010, reaching epidemic rates again in 2025.

The Japan National Institute of Infectious Diseases (NIID) has reported a significant increase in syphilis cases over the past decade, with the last four years averaging over 13,000 cases annually.

In 2025, the NIID confirmed that this unfortunate trend continued for the fourth consecutive year.

Among Japan's prefectures, Tokyo accounted for 25% of the national total of syphilis cases, followed by Osaka, Aichi, Fukuoka, and Kanagawa.

According to a December 2025 analysis, syphilis risk factors among predominantly heterosexual populations in urban Japan have significantly increased. These findings reveal that casual sexual partnerships and diverse sexual networks facilitated by dating applications and commercial sex services create unique transmission dynamics not adequately captured by previous research.

These researchers stated that promoting preventive measures among sex industry workers and patrons is crucial in Japan's cities.

Syphilis is a sexually transmitted infection (STI) that is generally transmitted by contact with infectious sores, through blood transfusions, or through mother-to-child transmission during pregnancy. This bacterial infection is caused by Treponema pallidum.

Syphilis can be treated with antibiotics such as penicillin. Furthermore, patients can become reinfected, so early antibiotic treatment is necessary.

After decades of clinical trial missteps, a December 18, 2025, study found syphilis vaccine development is beginning to gain momentum due to advances in understanding the outer membrane protein of Treponema pallidum, host–pathogen interactions, and the genomics of syphilis.

Preventing vertical transmission of Treponema pallidum subsp pallidum could be the most consequential target for a vaccine, given the global resurgence of congenital syphilis and adverse pregnancy outcomes.

As of late 2025, the U.S. Preventive Services Task Force and the American College of Obstetrics and Gynecology recommend that pregnant women be tested for syphilis. And in 2026, Alabama, Arizona, Colorado, Georgia, Maryland, Mississippi, Missouri, North Carolina, Tennessee, and Texas require syphilis testing during pregnancy.

With the global spreading of the Chikungunya virus expected to continue in 2026, Valneva SE and Serum Institute of India today announced that they have mutually agreed to discontinue their license agreement for Valneva's IXCHIQ® single-shot chikungunya vaccine.

As of December 31, 2025, Valneva's strategic intent in regaining full rights is to assume direct control over its supply chain and commercialization for endemic high-risk countries, thereby accelerating access for regions most affected by the disease.

According to the European Medicines Agency, IXCHIQ was shown to be effective at triggering the production of antibodies against the chikungunya virus in two primary studies. This is expected to reduce the risk of getting this mosquito-transmitted disease caused by the Chikungunya virus.

Supporting access to the vaccine in low-and middle-income countries falls within the framework of the funding agreement Valneva signed with the Coalition for Epidemic Preparedness Innovations in July 2024, with co-funding from the European Union.

Currently, the U.S. CDC has issued various Travel Health Notices for Chikungunya outbreaks, including a Level 2 alert for China in mid-December 2025.

The CDC advises international travelers to speak with a travel vaccine consultant regarding immunization options before visiting outbreak areas in 2026.