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.

Should I get the Flu Shot?

Influenza Pandemics

Influenza Prognosis

Influenza Infection in Animals

Influenza Research

Influenza Treatments

Influenza Immunization

Influenza Symptoms

Influenza Epidemiology

Latest Influenza News and Research

Watch: Fired CDC chief says RFK Jr. demanded she roll back vaccine policies without evidence

Susan Monarez, the former director of the Centers for Disease Control and Prevention, testified before the Senate Health, Education, Labor, and Pensions Committee on Sept. 17 in her first public remarks since she was fired.

17 Sep 2025

Antibody cocktail could change the way the world fights influenza

An unusual therapy developed at The Jackson Laboratory (JAX) could change the way the world fights influenza, one of the deadliest infectious diseases.

11 Sep 2025

Novel method accurately identifies therapeutic antibodies to treat infectious diseases

Scientists at Scripps Research have developed a novel method that uses artificial intelligence (AI) and advanced imaging techniques to more accurately and efficiently identify therapeutic antibodies to treat infectious diseases.

10 Sep 2025

Researchers reveal why no level of air pollution is safe for respiratory health

A review in the Journal of Clinical Investigation shows how particulate matter damages the lungs through oxidative stress, inflammation, and immune disruption. It links air pollution to asthma, COPD, lung cancer, infections, and millions of premature deaths, with no safe exposure threshold.

9 Sep 2025

Scientists identify key protein driving severe flu in older people

Scientists have discovered why older people are more likely to suffer severely from the flu, and can now use their findings to address this risk.

8 Sep 2025

Mushrooms deliver nutrition medicine and sustainability solutions in one package

This Food Science & Nutrition review highlights mushrooms as nutrient-rich functional foods packed with bioactive compounds that support human health. It explores their therapeutic, industrial, and environmental applications, from disease prevention and drug discovery to bioremediation and bioenergy.

8 Sep 2025

Can an allergy spray help prevent COVID-19?

Researchers determine the efficacy and safety of azelastine nasal spray for preventing SARS-CoV-2 infection in healthy adults.

8 Sep 2025

Scientists uncover human proteins hijacked by SARS-CoV-2 for replication

Despite vaccines and treatments, SARS-CoV-2-the virus that causes COVID-19-continues to pose a global health threat, driven by new variants and its ability to hijack human cells in ways that still aren't fully understood.

5 Sep 2025

Breakthrough technology enables faster and cheaper antibody analysis

Antibodies are the critical targeting agents of the immune system and the crux of immune therapy and vaccine development, but studying them is slow, expensive and labor-intensive.

4 Sep 2025

Penn State researchers reveal new function of antibody-producing cells

The body has an intricate system to defend against infections where each type of immune cell plays a distinct role. Now, a study led by researchers from the Penn State College of Medicine has uncovered a new function of the immune cells that are known for making antibodies.

3 Sep 2025

Changes at NIH give political appointees greater power to fund or block research

The Trump administration has given notice that political appointees, rather than scientists, will ultimately decide who gets grant money from the world’s largest biomedical research funder — the federal government's National Institutes of Health.

3 Sep 2025

How effective is the RSV vaccine for older adults?

A single dose of the RSV vaccine offers 58% protection against hospitalization in older adults, but effectiveness varies in immunocompromised individuals.

3 Sep 2025

AI model predicts flu vaccine strains more accurately than WHO

AI-based models like VaxSeer outperform traditional methods in flu vaccine strain selection, enhancing effectiveness and addressing global influenza challenges.

2 Sep 2025

Research reveals molecular details of ME/CFS and long COVID

Patients with chronic fatigue syndrome/myalgic encephalomyelitis (ME/CFS) have heightened innate immune responses to bacteria, viruses, and fungi. While these responses are essential to fight infection, they can cause damage when unchecked.

1 Sep 2025

Genetic clustering of swine influenza revealed in Northern Italy

A new scientific article, titled "Swine influenza surveillance in Italy uncovers regional and farm-based genetic clustering", has been published by Istituto Zooprofilattico Sperimentale delle Venezie as part of the Horizon Europe PAIR project.

29 Aug 2025

New guidelines improve care for respiratory infections in leukemia patients

People with leukemia have a weakened immune system due to the disease itself and treatment, which leads to an increased susceptibility to infections.

28 Aug 2025

New guidelines highlight importance of vaccination for heart patients

The American College of Cardiology has issued Concise Clinical Guidance (CCG) recommending vaccines to protect adults with heart disease against respiratory illness, including influenza, COVID-19 and RSV, and other diseases where vaccination is shown to offer cardiovascular protective benefits.

26 Aug 2025

Generative AI model scans emergency notes to identify high-risk avian influenza exposures

Researchers from the University of Maryland School of Medicine developed a new and highly effective application of an artificial intelligence (AI) tool to quickly scan notes in electronic medical records and identify high-risk patients who may have been infected with H5N1 avian influenza or "bird flu", according to new findings published in the journal Clinical Infectious Diseases.

25 Aug 2025

As measles exploded, officials in Texas looked to CDC scientists. Under Trump, no one answered.

As measles surged in Texas early this year, the Trump administration's actions sowed fear and confusion among CDC scientists that kept them from performing the agency's most critical function — emergency response — when it mattered most, an investigation from KFF Health News shows.

25 Aug 2025

COVID-19 vaccine successes boosted hesitancy - can trust and equity restore immunization?

Researchers show that countries with higher initial COVID-19 vaccine acceptance also achieved stronger booster uptake, but trust and access remain decisive. The commentary warns that vaccine successes also fueled hesitancy, demanding structural reforms, clear communication, and proactive strategies to protect immunization.

21 Aug 2025