Influenza

Influenza (the flu) is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness, and at times can lead to death. The best way to prevent the flu is by getting a flu vaccination each year. Every year in the United States, on average 5% to 20% of the population gets the flu; more than 200,000 people are hospitalized from flu complications, and; about 36,000 people die from flu-related causes. Some people, such as older people, young children, and people with certain health conditions, are at high risk for serious flu complications.

Types of Influenza

Influenza is caused by three types of RNA viruses called influenza types A, B and C, which all belong to the family Orthomyxoviridae.

Influenza Prognosis

Influenza Research

Influenza Immunization

Should I get the Flu Shot?

Influenza Epidemiology

Influenza Treatments

Influenza Pandemics

Influenza Infection in Animals

Influenza Symptoms

Latest Influenza News and Research

Scientists discover how herpes simplex virus softens cells to multiply faster

Herpes simplex virus partially liquifies the tightly packed, gel-like interior of human cell nuclei to copy itself faster, a new study shows.

6 Mar 2026

As ICE moved in, Minnesotans set up a shadow medical system. It’s a lesson for other cities.

Gabi has big brown eyes, pigtails, and a genetic condition that makes her bones brittle. They fracture easily, leaving the 2-year-old in such pain that her mother quit her job cleaning offices to stay home and cradle her in the one-bedroom apartment they share with six relatives.

5 Mar 2026

Environmental swabs reveal hidden avian viral diversity

Scientists at Duke-NUS Medical School have found that viruses circulating in live poultry markets can be detected more effectively by sampling the surrounding environment than by testing individual birds. The study, published in Nature Communications, shows that environmental sampling can uncover a broader range of poultry viruses-including highly pathogenic avian influenza strains that traditional surveillance may miss.

5 Mar 2026

Advancing influenza vaccine development: Sino Biological launches antigens for the 2026-2027 Northern Hemisphere influenza vaccine strains

The World Health Organization (WHO) has announced its recommendations for the 2026–2027 Northern Hemisphere influenza vaccine composition.

From Sino Biological Inc. 4 Mar 2026

Natural fungal supplement strengthens vaccine protection without increasing side effects

Researchers at University California San Diego School of Medicine have found that a natural fungal supplement taken at the time of COVID-19 vaccination reduced short-term vaccine side effects and helped antibodies - the body's natural immune defenders - last longer in people who had not previously been exposed to the virus.

4 Mar 2026

WHO updates 2026-2027 flu vaccine composition amidst viral evolution

The World Health Organization (WHO) today announced recommendations for the viral composition of influenza (or "flu") vaccines for the 2026-2027 northern hemisphere influenza season.

27 Feb 2026

Prior COVID infection increases kidney disease risk

Approximately one in seven adults in the United States has kidney disease, where the organs responsible for filtering waste and excess water from the blood are damaged, according to the Centers for Disease Control and Prevention.

25 Feb 2026

Lingering brain inflammation found after mild COVID infection

Even a mild case of COVID-19 or the flu can impact the body long after the fever and cough fade, according to new Tulane University research that may help explain why some people struggle to feel fully recovered weeks or months later.

25 Feb 2026

COVID and flu vaccination rates during pregnancy remain low in Norway

A study of over 50,000 pregnant women in Norway during the 2023/24 influenza season found that only 29.9% were vaccinated against influenza and 12.1% against COVID-19 during pregnancy, remaining far below recommended targets.

19 Feb 2026

New study uncovers link between pediatric OSA and higher risk of viral infections

A five-year study has revealed that children with sleep apnea are twice as likely to contract the flu or COVID-19, regardless of their age or weight.

17 Feb 2026

Innate immune priming may evolve into a broadly applicable infection-prevention strategy

Secondary infections caused by bacteria or viruses during hospital care remain a long-standing global challenge, despite advances in modern medicine.

16 Feb 2026

Preexisting flu immunity may offer baseline protection against avian influenza

Are seasonal flu antibodies also effective against avian flu? A team from the University of Geneva (UNIGE) has shown that a specific type of antibody associated with the former virus—already present throughout the population—may offer baseline protection against the latter.

10 Feb 2026

Influenza viruses can directly impair heart function

Mount Sinai researchers have identified a cellular mechanism linking infections from influenza A viruses (IAVs) to cardiovascular disease, providing critical insights on how influenza can damage the heart and increase the risk of a heart attack or other major cardiovascular event.

9 Feb 2026

Binghamton University receives $2.5 million to develop a next-generation avian flu vaccine

Outbreaks of avian flu at U.S. poultry farms led to more than $1.5 billion in losses over the last two years and drove egg prices to all-time highs in 2025.

6 Feb 2026

New DNA-based vaccine scaffolds boost targeted immune responses to HIV

One of the biggest hurdles in developing an HIV vaccine is coaxing the body to produce the right kind of immune cells and antibodies. In most vaccines, HIV proteins are attached to a larger protein scaffolding that mimics a virus.

6 Feb 2026

Artificial lung keeps patient alive after lung removal

Researchers evaluate the effectiveness of a novel extracorporeal total artificial lung system to enable bilateral pneumonectomy in patients with severe ARDS.

5 Feb 2026

Influenza D virus and canine coronavirus pose human risks

Two emerging pathogens with animal origins - influenza D virus and canine coronavirus - have so far been quietly flying under the radar, but researchers warn conditions are ripe for the viruses to spread more widely among humans.

5 Feb 2026

Why did influenza fail to spread in a crowded indoor setting?

The EMIT-2 trial shows zero influenza transmission despite ideal conditions, suggesting a perfect storm is needed for the virus to spread effectively.

4 Feb 2026

Six years after COVID-19: Lessons learned and pandemic preparedness

Six years ago, the Director-General of the World Health Organization sounded the highest global alarm available under international law at the time, declaring the outbreak of a new coronavirus disease (later known as COVID-19) a Public Health Emergency of International Concern (PHEIC).

3 Feb 2026