Travel can expose people to many valuable new experiences. It offers chances to see new sights, taste new foods, and meet new people. These opportunities may not exist in the same way at home.

However, travel can also expose people to new health risks. Many people in the United States view polio as a past disease. Yet, in some countries, polio transmission still occurs.

Recent reports show the polio virus appearing in several regions worldwide. Some common travel destinations, including the United Kingdom and Germany, now carry risk. In March 2026, the Centers for Disease Control and Prevention issued a level 2 travel notice.

A level 2 notice advises travelers to take extra precautions. It does not suggest canceling or avoiding nonessential travel. Polio continues to circulate across parts of Africa, the Middle East, and Europe.

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Sometimes important answers appear in unexpected and surprising places. People often find lost items hidden under cushions or inside drawers. Researchers discovered a similar surprise while studying vitamin D and COVID-19.

Scientists found regular vitamin D intake may reduce Long COVID risk. This finding came from researchers at Mass General Brigham. Their results were published in the Journal of Nutrition.

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When removing contamination, accidents can happen if people are not careful. For example, while dusting an antique bowl, someone might knock over a lamp. The lamp could fall and shatter into pieces.

A similar process can occur in the immune system. When the body responds to infection, mistakes sometimes occur. These errors can trigger cascading negative health effects.

Researchers from University of California, San Francisco recently investigated a link between Epstein–Barr virus (EBV) and Multiple sclerosis (MS). This finding is important because EBV is extremely common. About 96 percent of people become infected during their lifetime. Most infections occur during childhood and cause few symptoms.

In some cases, EBV causes infectious mononucleosis, often called “kissing disease.” MS is a chronic autoimmune disease of the central nervous system. In MS, the immune system attacks myelin surrounding nerve fibers. Myelin is a fatty, protein-rich layer that protects nerve signals. Nearly one million Americans currently live with MS.

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False convictions in criminal cases can cause serious harm. Similar damage can occur when false narratives spread about disease origins. Conspiracy theories, misinformation, and distrust of medicine often follow these claims. A recent study examining viral evolution offers new insight into how many pandemic viruses emerge.

The research focused on pandemic viruses. Specifically, it examined how they acquire their ability to infect humans. This can occur naturally or through laboratory manipulation. Many pandemic viruses are zoonotic. These viruses originate in animals before spreading to people. Some public claims argue that certain viruses gained their human infectivity through laboratory work. However, the study’s findings challenge that idea for most major outbreaks.

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Typhoid fever is an old bacterial illness that still threatens global health. Many people in developed nations assume the disease disappeared long ago. Yet this belief is mistaken because the bacterium never vanished worldwide. Instead, the disease remains common in many developing nations today.

Typhoid fever is caused by the bacterium Salmonella enterica serovar Typhi. The bacterium spreads through contaminated food or drinking water. Poor sanitation and unsafe water systems allow the infection to circulate widely. As a result, many regions still experience frequent outbreaks of the disease.

Researchers warn that typhoid fever is becoming more difficult to treat. A 2022 study published in The Lancet revealed troubling new trends. Scientists found that many S. Typhi strains are gaining resistance to antibiotics. This discovery raises concern because antibiotics remain the only effective treatment.

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COVID-19 infection during pregnancy has raised concerns since the start of the pandemic. Earlier research showed that the virus could increase the risk of complications such as stillbirth, premature birth, and preeclampsia. Preeclampsia is a dangerous blood pressure disorder that threatens both the pregnant person and the developing fetus.

A recent international study suggests that COVID-19 vaccination may help reduce this risk. Researchers found that coronavirus infection increased the likelihood of preeclampsia by about 45 percent among pregnant participants compared with those who were not infected. The increase was even greater among people who were unvaccinated when they became infected. In that group, the risk rose by roughly 78 percent.

Vaccination appeared to offer meaningful protection. Participants who received the primary COVID-19 vaccination and stayed up to date with booster doses had a 33 percent lower risk of developing preeclampsia. The protective effect was even stronger among those with existing health conditions. Pregnant participants with illnesses such as diabetes or heart disease who received a booster saw their risk fall by about 58 percent.

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Researchers have long studied ancient viruses by examining preserved DNA fragments. DNA survives relatively well in bones, teeth, and other remains. Because of this stability, scientists have discovered viral DNA that is tens of thousands of years old. Some DNA viruses identified in ancient human remains date back nearly 50,000 years. These discoveries help researchers trace how diseases evolved and spread through early human populations.

RNA viruses present a far greater challenge. RNA molecules are fragile and degrade quickly after death. In most cases, RNA dissolves within hours once cells begin to break down. This instability makes it extremely difficult for scientists to detect ancient RNA viruses. As a result, the evolutionary history of many RNA viruses has remained largely unknown.

A recent study, however, uncovered evidence of a much older RNA virus than previously confirmed. Researchers identified fragments of a rhinovirus, the virus responsible for many common colds. The virus infected a woman who lived roughly 250 years ago. This discovery represents the oldest RNA virus genome ever reconstructed from human remains.

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They say the eyes are windows to the soul. Science cannot prove that old saying true. Still, the eyes may reveal something unexpected: signs of Alzheimer’s disease.

Alzheimer’s is a form of dementia. Dementia affects memory, thinking, and social abilities. Doctors have long searched for earlier warning signs of the disease.

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In pulpy adventure stories, one hero often stays behind. “Save yourselves,” they cry. “I’ll hold them off.” They may not survive. But if they fall, the enemy falls with them.

New research suggests certain immune cells in the brain behave in a strikingly similar way. When Toxoplasma gondii infects T cells, those cells can destroy themselves. In doing so, they eliminate the parasite hiding inside them.

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The idea of a vaccine that shields against almost any infectious disease sounds mythical. Yet researchers at Stanford Medicine recently unveiled what they call a universal vaccine. This nasal spray could protect against COVID-19, influenza, bacterial infections, and allergies.

The spray primes immune cells in the lungs for future threats. In mice, it sharply reduced viral load. It also prevented severe symptoms and blocked allergic reactions.

Researchers tested it against coronaviruses, Staphylococcus aureus, and Acinetobacter baumannii. The latter two bacteria commonly spread in hospital settings. The vaccine also stopped allergic reactions to dust mites.

Human trials will determine whether these results translate. If successful, one nasal spray could replace several yearly shots.

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