Sep 18, 2024 · There are four types of influenza viruses: A, B, C, and D. Influenza A and B viruses cause seasonal epidemics of disease in people (known as flu season) almost every winter in the United States.

Jan 22, 2025 · Influenza A and influenza B are the main strains of flu virus. Type A causes more cases, more severe illness and infects many species. Type B only infects humans.

Jan 23, 2025 · Three types of flu viruses affect humans: types A, B, and C. Type A and B cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, …

Influenza viruses, particularly influenza A virus, evolve quickly, so flu vaccines are updated regularly to match which influenza strains are in circulation. Vaccines provide protection against influenza A virus subtypes H1N1 and H3N2 and one or two influenza B virus subtypes.

Sep 26, 2023 · What are the strains of flu? There are three types of flu viruses that affect people. They’re known as influenza viruses A, B and C. Influenza A and influenza B viruses are the heavy hitters.

Influenza viruses are classified into 4 types: A, B, C, and D. Influenza A and B viruses commonly cause illness in humans and seasonal epidemics. Influenza A viruses are classified into subtypes based on the surface proteins hemagglutinin (HA) and neuraminidase (NA).

Jul 23, 2024 · There are different types and subtypes of flu. We’ll take a look at influenza A vs. B in terms of prevalence, how contagious they are, what the vaccine covers, and severity and recovery.

Jan 23, 2023 · Over the past few decades, more lethal strains of the influenza virus have evolved. Besides infecting humans, these viruses also infect animals. Clinicians should be aware that all rapid tests for detecting influenza have limited sensitivity, and false-negative results are common.

May 13, 2010 · Influenza A subtypes and B viruses are further classified by strains. The nomenclature for influenza virus isolates includes the influenza virus type (A or B), host species (omitted if human in origin), geographical site, serial number, year of isolation and, lastly, the H and N variants in brackets.

These novel strains are the influenza virus's evolutionary adaptations to a strong population-wide immune response. Antigenic drift is the primary reason people can get influenza more than once and why it is necessary to annually review and update the composition of influenza vaccines.