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 Treatments

Influenza Immunization

Influenza Epidemiology

Influenza Pandemics

Influenza Prognosis

Should I get the Flu Shot?

Influenza Infection in Animals

Influenza Research

Influenza Symptoms

Latest Influenza News and Research

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

Bacteria repurpose viral injection systems to target diverse cells

New study shows how bacteria adapted a virus-derived injection system to recognize and attach to many different types of cells.

2 Feb 2026

Overlooked animal viruses slipping past global disease surveillance

The study on Influenza D and Canine Coronavirus HuPn-2018 underscores urgent needs for targeted surveillance and diagnostics in infectious disease research.

2 Feb 2026

How the CDC prepares influenza vaccines for pandemics

CDC scientists outline the comprehensive methodology involved in the development of influenza candidate vaccine viruses.

2 Feb 2026

Nasal spray vaccine prevents infection from highly pathogenic H5N1 virus

Researchers at WashU Medicine have developed a nasal vaccine against the highly pathogenic H5N1 avian influenza virus, or bird flu, which has jumped from wild birds to livestock to humans.

30 Jan 2026

Genetic inheritance and life experience leave distinct epigenetic marks in immune cells

The COVID-19 pandemic gave us tremendous perspective on how wildly symptoms and outcomes can vary between patients experiencing the same infection.

29 Jan 2026

Emerging animal viruses may pose overlooked threats to future human outbreaks

29 Jan 2026

How DNA and life experiences leave distinct marks on the human immune system

Using single-cell epigenomic profiling of immune cells from 110 individuals, researchers show that genetic variation and environmental exposures shape the human immune system through distinct DNA methylation mechanisms. Genetic effects concentrate within gene bodies of memory cells, while environmental exposures primarily remodel regulatory regions in naive immune cells.

28 Jan 2026

A shingles vaccine may delay dementia onset

Research indicates the herpes zoster vaccine may reduce dementia rates by 2%, highlighting its potential role in promoting brain health in aging populations.

28 Jan 2026

Survey shows growing public familiarity with RSV vaccines and antibody injections

Amid a surprisingly severe flu season and a Covid-19 resurgence, those highly contagious respiratory illnesses are drawing the largest share of media coverage and public attention.

21 Jan 2026

High-dose flu shots lower hospitalization risk in older adults

High-dose influenza vaccines may lower serious hospitalization rates in older adults, particularly those with diabetes, according to a recent Danish trial.

20 Jan 2026

Shingles vaccination may slow biological aging in older adults

Shingles vaccination not only protects against the disease but may also contribute to slower biological aging in older adults, according to a new USC Leonard Davis School of Gerontology study.

20 Jan 2026

Vaccines are helping older people more than we knew

Let's be clear: The primary reason to be vaccinated against shingles is that two shots provide at least 90% protection against a painful, blistering disease that a third of Americans will suffer in their lifetimes, one that can cause lingering nerve pain and other nasty long-term consequences.

14 Jan 2026