Immune and infectious diseases Archive

A cough that lingers for weeks after a cold can be confusing. Learn why it can persist, what else might be going on, and when to see your doctor.

In the US, widespread vaccination halted the ongoing spread of measles more than 20 years ago, but recent outbreaks have flared in over 20 US states, leading to hospitalizations and at least two deaths. Measles is highly preventable - here's what you need to know.

Having a persistent illness is challenging. It means having to make changes and adjustments to accommodate your needs, but it does not have to mean giving up on everything you enjoy.

Daily nasal irrigation (nasal rinses) may reduce symptom severity and the duration of a cold. It can also relieve the congestion caused by sinus infections and allergies. By means of a squeeze bottle, neti pot, or battery-powered system, saline is inserted into one nostril and flows out the other.

Elderberry syrup or tea may help reduce the duration and severity of cold and flu symptoms, but the evidence for these benefits is uncertain. Claims that elderberry products can prevent viral infections or boost immunity are unproven.

About half of Americans have herpes simplex virus type 1, which causes cold sores that can recur periodically. The virus can't be eliminated, but topical and oral treatments can help. In addition, people can avoid cold sore triggers such as stress or fatigue.

Shingles occurs when the dormant chickenpox virus reactivates, causing tingling, burning, and a painful, blistering rash. Shingles can affect anyone who has had chickenpox, with higher risk after age 50 and in people with weakened immunity. Diagnosis and treatment within three days of the rash appearing can shorten the illness and reduce severity. Most people recover completely from shingles, but there may be complications, such as post-herpetic neuralgia, which is pain that can be severe and long-lasting. Vaccination is the best way to prevent shingles and its complications.

A 2025 study suggests that respiratory syncytial virus (RSV) can lead to heart-related complications, such as a heart attack, chronic heart failure, or an irregular heartbeat-even in people without a previous heart condition.

A 2025 study of 250 people found that the brain can tell the immune system to prepare for impending infection even before a microbe enters the body. Scientists asked volunteers to don virtual reality headsets that showed various virtual people approaching them. Some of those approaching appeared to be healthy and others appeared to be sick. Brain scans and blood tests showed that participants' brains activated their immune systems when a virtual sick person simply came near them.