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 Epidemiology

Influenza Treatments

Influenza Prognosis

Influenza Symptoms

Influenza Pandemics

Influenza Immunization

Influenza Research

Influenza Infection in Animals

Latest Influenza News and Research

Protein targeted by cancer drugs may help the body fight influenza

A protein already targeted by FDA-approved cancer drugs may also help the body fight influenza, according to new research from The Jackson Laboratory (JAX).

18 Mar 2026

Targeting two influenza proteins may reduce viral transmission

A long-running debate in vaccine design revolves around whether a vaccine should be optimized to prevent the virus from replicating inside an infected host or prevent the virus from transmitting to others.

13 Mar 2026

Prior flu exposure may weaken the immune response to other strains

Prior exposure to one strain of influenza virus may weaken children's ability to mount an effective antibody response against their subsequent exposure to a different flu strain, according to a study led by Weill Cornell Medicine investigators.

11 Mar 2026

Severe COVID and flu infections increase risk of lung cancer

Severe COVID-19 and influenza infections prime the lungs for cancer and can accelerate the disease's development, but vaccination heads off those harmful effects, new research from UVA Health's Beirne B. Carter Center for Immunology Research and UVA Comprehensive Cancer Center indicates.

11 Mar 2026

DNA origami vaccine platform shows promise against multiple infectious viruses

The COVID-19 pandemic brought messenger RNA (mRNA) vaccines to the forefront of global health care. After their clinical trial stages, the first COVID-19 mRNA vaccine was administered on 8 December 2020 and mathematical models suggest that mRNA vaccines prevented at least 14.4 million deaths from COVID-19 in the first year alone.

11 Mar 2026

Training game helps nurses spot fungal infections in breastfeeding

This educational game simulates breastfeeding complications, equipping nurses with skills to detect and manage fungal infections in the nipple-areola area.

11 Mar 2026

New index provides state-level vulnerability to influenza-like illness

Infectious disease can afflict a population in complex ways. Understanding the varying risks is an equally complex challenge.

9 Mar 2026

Most pandemic viruses show little adaptation before infecting humans

A new University of California San Diego study published in Cell challenges a long-standing assumption about how animal viruses become capable of sparking human epidemics and pandemics.

9 Mar 2026

Newsom picks a dogfight with Trump and RFK Jr. on public health

California Gov. Gavin Newsom has positioned himself as a national public health leader by staking out science-backed policies in contrast with the Trump administration.

9 Mar 2026

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