Dec 2, 2022 · Influenza (Flu) Viruses There are two main types of human flu viruses: types A and B. The flu A and B viruses that routinely spread in people are responsible for seasonal flu epidemics each year. Flu A viruses can be broken down into sub-types depending on the genes that make up the surface proteins. Strains of influenza B are exclusively contracted by humans, while A can be carried (and spread) by animals, however, both strains are transmitted mainly by respiratory droplets from coughing and contact with an infected person.Nov 7, 2022 · A healthcare professional may be able to test for COVID-19, the flu and RSV at the same visit. Abbott offers several diagnostic tools to aid in fast, reliable respiratory virus testing. From our ID-NOW™ rapid system to the Alinity m Resp-4-Plex to the Panbio COVID-19/Flu A&B Rapid Panel test*, we are equipping clinicians with tools to ... for influenza A and B were not re-established with the modified device and may vary from previous performance. Performance characteristics may vary against other emerging influenza viruses. If ...The four types of influenza are A, B, C, and D. Types A and B are widespread during most winters in the United States. Type C is milder than types A or B and does not spread as easily. Type D ...Influenza virus from the family Orthomyxoviridae are enveloped negative-strand RNA viruses with segmented genomes containing seven to eight gene segments. Of the five genera in the family, only influenza A virus (IAV), influenza B and C viruses are medically relevant to humans. Influenza A and B viruses have a similar structure whereby these ...Influenza types A and B. These 2 types of viruses cause widespread illness (epidemics) almost every winter. They often lead to more people needing to go to the hospital, and more people dying from the flu. Public health officials focus on stopping the spread of types A and B. One of the reasons the flu remains a problem is because the viruses ...The flu is caused by an influenza virus. Most people get the flu when they breathe in tiny airborne droplets from the coughs or sneezes of someone who has the flu. You can also catch the flu if you touch something with the virus on it, and then touch your mouth, nose, or eyes. People often confuse colds and flu.Jun 28, 2018 · Abstract. Influenza is an infectious respiratory disease that, in humans, is caused by influenza A and influenza B viruses. Typically characterized by annual seasonal epidemics, sporadic pandemic ... The fastest molecular flu test just got faster and even better. Now with early detection and positive results in as few as 5 minutes, allowing you to make effective clinical decisions sooner. Abbott ID NOW is a rapid, instrument-based system for the qualitative detection of infectious diseases using isothermal nucleic acid amplification technology.Rapid Molecular Assay [influenza viral RNA or nucleic acid detection] A and B. NP 5 swab, nasal swab. 15-30 minutes 6. Yes/No 6. Immunofluorescence, Direct (DFA) or Indirect (IFA) Florescent Antibody Staining [antigen detection] A and B. NP 4 swab or wash, bronchial wash, nasal or endotracheal aspirate. 1-4 hours. May 28, 2009 · Influenza A viruses infect a range of mammalian (e.g. pigs and horses) and avian species, whereas type B and C infections are largely restricted to humans. Only types A and B cause human disease of any concern. All of the currently identified 16 HA and 9 NA subtypes of influenza A viruses are maintained in wild, aquatic bird populations. Doctors & departments Overview Flu (influenza) is an infection of the nose, throat and lungs, which are part of the respiratory system. Influenza is commonly called the flu, but it's not the same as stomach "flu" viruses that cause diarrhea and vomiting. Most people with the flu get better on their own.types of influenza viruses: A, B, and C. Type A viruses are the most prevalent and are associated with most serious epidemics. Type B viruses produce a disease that is generally milder than that caused by type A. Type C viruses have never been associated with a large epidemic of human disease. Both type A and B viruses canInfluenza, commonly known as " the flu ", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin from one to four days after exposure to the virus (typically two days) and last for about 2–8 days.Room temperature (15°C to 30°C/59°F to 86°F) Internal controls. Positive and negative included. External controls. Positive and negative included. PPA* (versus an FDA-cleared influenza A and B molecular assay) A: 81.5%, B: 80.9%. NPA* (versus an FDA-cleared influenza A and B molecular assay) A: 97.8%, B: 99.1%. (SARS-CoV-2) (Coronavirus disease [COVID-19]), influenza virus types A and B, and respiratory syncytial virus, multiplex amplified probe technique Influenza/RSV and COVID-19 0240U Infectious disease (viral respiratory tract infection), pathogen-specific RNA, 3 targets (severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], influenza A ... Jan 12, 2023 · Nationally, flu activity during the 2021-2022 season began to increase in November and remained elevated until mid-June with two different waves of influenza A (H3N2) virus activity occurring; the first peaked in late December 2021, and the second in April 2022. Prior to the emergence of SARS-CoV-2, flu activity would most commonly begin to ... Influenza B almost exclusively infects humans and is less common than influenza A. Flu type B also mutates about two to three times more slowly than influenza A. Because humans are the natural host of influenza B, pandemics generally do not occur with influenza B viruses. 22. Although scientists can classify and monitor the different types of ... 1 hour ago · The CDC’s website says you can get a flu shot and a COVID-19 shot at the same time --in the same arm or one in each arm--if that is convenient and you are due for vaccination, but they do not ... Yes. There are tests that will check for seasonal influenza A and B viruses and SARS-CoV-2, the virus that causes COVID-19. Testing for these viruses at the same time gives public health officials important information about how flu and COVID-19 are spreading and what prevention steps people should take.There are two main types of influenza viruses: types A and B. Both type A and B influenza viruses regularly spread in people and are responsible for seasonal flu each year. WHAT IS THE The last time the state saw a significant wave of influenza B was in 2019, when 12,950 cases of influenza B were recorded. In 2020, 720 notifications of influenza B were made. There were 57 in ...Influenza types A and B. These 2 types of viruses cause widespread illness (epidemics) almost every winter. They often lead to more people needing to go to the hospital, and more people dying from the flu. Public health officials focus on stopping the spread of types A and B. One of the reasons the flu remains a problem is because the viruses ...The influenza A and B virus genomes each comprise eight negative-sense, single-stranded viral RNA (vRNA) segments, while influenza C virus has a seven-segment genome. (See Table 1.) The eight segments of influenza A and B viruses (and the seven segments of influenza C virus) are numbered in order of decreasing length.CoV-2 negative results are presumptive and confirmation with a molecular assay, if necessary for patient management, may be performed. All negative influenza A and B test results are Nov 7, 2022 · A healthcare professional may be able to test for COVID-19, the flu and RSV at the same visit. Abbott offers several diagnostic tools to aid in fast, reliable respiratory virus testing. From our ID-NOW™ rapid system to the Alinity m Resp-4-Plex to the Panbio COVID-19/Flu A&B Rapid Panel test*, we are equipping clinicians with tools to ... Mar 10, 2020 · Objectives Timely implementation of influenza infection control and treatment can significantly reduce the impact on Hospital resources and patient management when demand is at peak. Turnaround times of Laboratory based screening tests for the diagnosis of influenza may have an impact on the implementation of infection control measures and treatment. In this study the objectives included ... There are four types of influenza virus: influenza A, B, C, and D. Types A and B are responsible for the flu epidemics that occur in the United States most winters. Influenza, or the flu, is a ...The influenza A and B virus genomes each comprise eight negative-sense, single-stranded viral RNA (vRNA) segments, while influenza C virus has a seven-segment genome. (See Table 1.) The eight segments of influenza A and B viruses (and the seven segments of influenza C virus) are numbered in order of decreasing length.Rapid Molecular Assay [influenza viral RNA or nucleic acid detection] A and B. NP 5 swab, nasal swab. 15-30 minutes 6. Yes/No 6. Immunofluorescence, Direct (DFA) or Indirect (IFA) Florescent Antibody Staining [antigen detection] A and B. NP 4 swab or wash, bronchial wash, nasal or endotracheal aspirate. 1-4 hours.There are four types of influenza virus: influenza A, B, C, and D. Types A and B are responsible for the flu epidemics that occur in the United States most winters. Influenza, or the flu, is a ...Influenza virus from the family Orthomyxoviridae are enveloped negative-strand RNA viruses with segmented genomes containing seven to eight gene segments. Of the five genera in the family, only influenza A virus (IAV), influenza B and C viruses are medically relevant to humans. Influenza A and B viruses have a similar structure whereby these ...Follow recommended infection prevention and control measures1. SARS-CoV-2 Testing. Test for SARS-CoV-2 by nucleic acid detection 2. , 3 ; OR if not available, by SARS-CoV-2 antigen detection assay. 5. a) If SARS-CoV-2 Test result is positive, administer supportive care. If the patient is at high risk for progression to severe COVID-19 ... Performance characteristics for influenza A and B were established during February through March 2011 when influenza viruses A/California/7/2009 (2009 H1N1), A/Perth/16/2009 (H3N2), and B/Brisbane/60/2008 (Victoria-Like) were the predominant influenza viruses in circulation according to the Morbidity and Mortality Weekly Influenza (the flu) is a viral infection that causes symptoms like fever and chills, sneezing, coughing and a sore throat. The flu can be serious for some people, but if you are otherwise fit and healthy you usually don’t need to see a doctor. There is a vaccine available for the flu, and it’s recommended that everyone over the age of 6 ...Abstract. Influenza is an infectious respiratory disease that, in humans, is caused by influenza A and influenza B viruses. Typically characterized by annual seasonal epidemics, sporadic pandemic ...For Influenza, the test demonstrated a positive percent agreement of 83.3% (Flu A) and 80% (Flu B) and a negative percent agreement of 97.5% (Flu A) and 95.3% (Flu B) versus RT-PCR, based on ...Mayo Clinic offers flu shots in Arizona, Florida and Minnesota. Your health care provider will conduct a physical exam, look for signs and symptoms of flu, and possibly order a test that detects influenza viruses. During times when flu is widespread, you may not need to be tested for it. Your health care provider may diagnose you based on your ...The CDC Influenza SARS-CoV-2 (Flu SC2) Multiplex Assay is a real-time reverse-transcription polymerase chain reaction (rRT-PCR) laboratory test that can simultaneously detect and differentiate between influenza A, influenza B, and SARS-CoV-2 in upper or lower respiratory specimens. The test is a highly accurate, nucleic acid-based diagnostic ...Influenza, commonly known as " the flu ", is an infectious disease caused by influenza viruses. Symptoms range from mild to severe and often include fever, runny nose, sore throat, muscle pain, headache, coughing, and fatigue. These symptoms begin from one to four days after exposure to the virus (typically two days) and last for about 2–8 days.Jul 14, 2023 · The last time the state saw a significant wave of influenza B was in 2019, when 12,950 cases of influenza B were recorded. In 2020, 720 notifications of influenza B were made. There were 57 in ... FluNet Summary. This content is last updated on 22 August 2023. National Influenza Centres (NICs) and other national influenza laboratories from 108 countries, areas or territories reported data to FluNet for the time period from 24 July 2023 to 06 August 2023* (data as of 18/08/2023 06:58:57AM UTC). The WHO GISRS laboratories tested more than ...There are three types of flu viruses: A, B, and C. Type A and B cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, coughing, and running high... for influenza A and B were not re-established with the modified device and may vary from previous performance. Performance characteristics may vary against other emerging influenza viruses. If ...Influenza — commonly known as the flu — is a respiratory infection caused by flu viruses. There are three main types of influenza: A, B, and C. Types A and B are similar, but influenza B can ...Jan 12, 2023 · Flu symptoms for both A and B tend to appear in progression, beginning with a sudden onset of fever. Other early symptoms include: Dry cough Runny nose Sore throat Body aches Headache Fatigue When young children acquire influenza, they may experience nausea, vomiting, or diarrhea in addition to respiratory symptoms. Influenza (flu): The flu is commonly caused by type A and B influenza strains. Symptoms are typically more severe than the common cold and can include coughing, fever (or chills), muscle aches, shortness of breath, and more.Different types of COVID-19 and flu test kits use different testing methodologies. They can either be antigen-based or use molecular techniques. Diagnostic tests for viral antigens or RNA indicate a current infection. Antigen Tests. Antigen assays typically detect nucleocapsid proteins from a virus like SARS-CoV-2 or Flu A+B.1 hour ago · The CDC’s website says you can get a flu shot and a COVID-19 shot at the same time --in the same arm or one in each arm--if that is convenient and you are due for vaccination, but they do not ... Background. Rapid influenza diagnostic tests (RIDTs) are immunoassays that can identify the presence of influenza A and B viral nucleoprotein antigens in respiratory specimens, and display the result in a qualitative way (positive vs. negative) (1). In the United States, a number of RIDTs are commercially available.Print. The Centers for Disease Control and Prevention (CDC) recognizes that school administrators, teachers, staff, and parents are concerned about influenza (flu), particularly its effects on children. Educators and staff can help slow the spread of respiratory illnesses, including flu. On this page, you will find information on preventing the ...The CDC Influenza SARS-CoV-2 (Flu SC2) Multiplex Assay is a real-time reverse-transcription polymerase chain reaction (rRT-PCR) laboratory test that can simultaneously detect and differentiate between influenza A, influenza B, and SARS-CoV-2 in upper or lower respiratory specimens. The test is a highly accurate, nucleic acid-based diagnostic ...serious flu complications. There are two main types of . influenza viruses: types A and B. Both type A and B . influenza viruses regularly spread in people, and are . responsible for seasonal flu ...Jul 14, 2023 · The last time the state saw a significant wave of influenza B was in 2019, when 12,950 cases of influenza B were recorded. In 2020, 720 notifications of influenza B were made. There were 57 in ... Mar 29, 2017 · Strains of influenza B are exclusively contracted by humans, while A can be carried (and spread) by animals, however, both strains are transmitted mainly by respiratory droplets from coughing and contact with an infected person. This allows strains of A to be spread more rapidly than B, while also meaning strains of B cannot cause pandemics ... Rapid influenza diagnostic tests (RIDTs) detect influenza viral antigens in respiratory tract specimens. Available RIDTS detect and differentiate between type influenza A and B viruses, but do not specifically identify or differentiate subtypes of influenza A viruses. RIDTs are not recommended for use in hospitalized patients with suspected ... May 18, 2021 · H1N1 flu is a subtype of influenza A. Subtypes of influenza A are categorized based on two proteins on the surface of the virus, hemagglutinin (H) and neuraminidase (N). There are many H and N subtypes, and each one is numbered. All H and N flu subtypes are influenza A viruses. Each influenza subtype has many different strains of influenza virus. Feb 2, 2023 · Influenza, known as “ the flu ,” is a highly contagious respiratory virus. It’s most common during the fall and winter months. It typically spreads through respiratory droplets when a person... There are two main types of influenza viruses: types A and B. Both type A and B influenza viruses regularly spread in people and are responsible for seasonal flu each year. WHAT IS THE The US is only about three months into the 2019–2020 flu season, and the illness has already left its mark—but it's a little different this year. According to the Centers for Disease Control ...Rapid assays for the diagnosis of influenza A and B viruses in patients evaluated at a large tertiary care children's hospital during two consecutive winter seasons. J Clin Virol. 2008;41(2):143-147. Cruz AT, Demmler-Harrison GJ, Caviness AC, et al. Performance of a rapid influenza test in children during the H1N1 2009 influenza a outbreak.Influenza A and B: None: None: NPS in VTM: 3.5 hr: Moderate: Luminex: Verigene Respiratory Virus Nucleic Acid Test Plus: Verigene SP: Influenza A and B: H1, H1pdm09, H3: Respiratory Syncytial Virus (A, B) NPS in VTM: 3.5 hr: Moderate: Luminex: Verigene RP Flex: VERIGENE Reader VERIGENE Processor SP: Influenza A and B: H1/H1pdm09, H3Influenza A viruses infect a range of mammalian (e.g. pigs and horses) and avian species, whereas type B and C infections are largely restricted to humans. Only types A and B cause human disease of any concern. All of the currently identified 16 HA and 9 NA subtypes of influenza A viruses are maintained in wild, aquatic bird populations.Mar 29, 2017 · Strains of influenza B are exclusively contracted by humans, while A can be carried (and spread) by animals, however, both strains are transmitted mainly by respiratory droplets from coughing and contact with an infected person. This allows strains of A to be spread more rapidly than B, while also meaning strains of B cannot cause pandemics ... Influenza, known as “ the flu ,” is a highly contagious respiratory virus. It’s most common during the fall and winter months. It typically spreads through respiratory droplets when a person...Rapid influenza diagnostic tests (RIDTs) detect influenza viral antigens in respiratory tract specimens. Available RIDTS detect and differentiate between type influenza A and B viruses, but do not specifically identify or differentiate subtypes of influenza A viruses. RIDTs are not recommended for use in hospitalized patients with suspected ... Influenza A and B: None: None: NPS in VTM: 3.5 hr: Moderate: Luminex: Verigene Respiratory Virus Nucleic Acid Test Plus: Verigene SP: Influenza A and B: H1, H1pdm09, H3: Respiratory Syncytial Virus (A, B) NPS in VTM: 3.5 hr: Moderate: Luminex: Verigene RP Flex: VERIGENE Reader VERIGENE Processor SP: Influenza A and B: H1/H1pdm09, H3 Oct 3, 2022 · fever* or feeling feverish/chills. cough. sore throat. runny or stuffy nose. muscle or body aches. headaches. fatigue (tiredness) some people may have vomiting and diarrhea, though this is more common in children than adults. *It’s important to note that not everyone with flu will have a fever. FluNet Summary. This content is last updated on 22 August 2023. National Influenza Centres (NICs) and other national influenza laboratories from 108 countries, areas or territories reported data to FluNet for the time period from 24 July 2023 to 06 August 2023* (data as of 18/08/2023 06:58:57AM UTC). The WHO GISRS laboratories tested more than ...Rapid assays for the diagnosis of influenza A and B viruses in patients evaluated at a large tertiary care children's hospital during two consecutive winter seasons. J Clin Virol. 2008;41(2):143-147. Cruz AT, Demmler-Harrison GJ, Caviness AC, et al. Performance of a rapid influenza test in children during the H1N1 2009 influenza a outbreak.Performance characteristics for influenza A and B were established during February through March 2011 when influenza viruses A/California/7/2009 (2009 H1N1), A/Perth/16/2009 (H3N2), and B/Brisbane/60/2008 (Victoria-Like) were the predominant influenza viruses in circulation according to the Morbidity and Mortality WeeklyInfluenza types A and B. These 2 types of viruses cause widespread illness (epidemics) almost every winter. They often lead to more people needing to go to the hospital, and more people dying from the flu. Public health officials focus on stopping the spread of types A and B. One of the reasons the flu remains a problem is because the viruses ... FluNet Summary. This content is last updated on 22 August 2023. National Influenza Centres (NICs) and other national influenza laboratories from 108 countries, areas or territories reported data to FluNet for the time period from 24 July 2023 to 06 August 2023* (data as of 18/08/2023 06:58:57AM UTC). The WHO GISRS laboratories tested more than ...Dec 22, 2020 · Influenza A and B also have the same chances of complications from the flu, including a potential risk of death. (Beware of these deadly flu signs.) How are influenza A and B transmitted? Like SARS-CoV-2, the virus that causes Covid-19, both flu A and B spread from person to person, up to a distance of about six feet. Influenza — commonly known as the flu — is a respiratory infection caused by flu viruses. There are three main types of influenza: A, B, and C. Types A and B are similar, but influenza B can ...The CDC Influenza SARS-CoV-2 (Flu SC2) Multiplex Assay is a real-time reverse-transcription polymerase chain reaction (rRT-PCR) laboratory test that can simultaneously detect and differentiate between influenza A, influenza B, and SARS-CoV-2 in upper or lower respiratory specimens. The test is a highly accurate, nucleic acid-based diagnostic ...Waner JL, Todd, SI, Shalaby H, et al. Comparison of Directigen FLU-A with viral isolation and direct immunofluorescence for the rapid detection and identification of influenza A virus. J Clin Microbiol. 1991; 29(3):479-482. 2037665 Yes, for some people. There are three flu vaccines that are preferentially recommended for people 65 years and older. These are Fluzone High-Dose Quadrivalent vaccine, Flublok Quadrivalent recombinant flu vaccine and Fluad Quadrivalent adjuvanted flu vaccine . This recommendation was based on a review of available studies which suggests that ...Yes, for some people. There are three flu vaccines that are preferentially recommended for people 65 years and older. These are Fluzone High-Dose Quadrivalent vaccine, Flublok Quadrivalent recombinant flu vaccine and Fluad Quadrivalent adjuvanted flu vaccine . This recommendation was based on a review of available studies which suggests that ...Rapid influenza diagnostic tests (RIDTs) RIDTs, also called flu antigen tests, are the most common type of flu test. They can identify the presence of influenza A and B, and they work by detecting the parts of the flu virus called antigens that trigger an immune response. RIDTs usually involve inserting a swab into your nostril to get a sample. LP248181-2 Influenza virus A & B & Respiratory syncytial virus RNA panel Influenza viruses A and B are single-stranded RNA enveloped viruses belonging to the Orthomyxoviridae family. The symptoms of infection of Influenza A and B include fever, cough, sore throat, rhinorrhea, nasal congestion, headache, myalgia and malaise.Oct 15, 2019 · The four types of influenza are A, B, C, and D. Types A and B are widespread during most winters in the United States. Type C is milder than types A or B and does not spread as easily. Type D ... Mar 26, 2018 · Influenza — commonly known as the flu — is a respiratory infection caused by flu viruses. There are three main types of influenza: A, B, and C. Types A and B are similar, but influenza B can ... Dec 3, 2020 · Influenza A and B infect humans each flu season and are both highly contagious. While treatment and prevention are the same, flu B tends to be less common. Search Nationally, flu activity during the 2021-2022 season began to increase in November and remained elevated until mid-June with two different waves of influenza A (H3N2) virus activity occurring; the first peaked in late December 2021, and the second in April 2022. Prior to the emergence of SARS-CoV-2, flu activity would most commonly begin to ...
Influenza — commonly known as the flu — is a respiratory infection caused by flu viruses. There are three main types of influenza: A, B, and C. Types A and B are similar, but influenza B can .... Mr popper
1 hour ago · The CDC’s website says you can get a flu shot and a COVID-19 shot at the same time --in the same arm or one in each arm--if that is convenient and you are due for vaccination, but they do not ... serious flu complications. There are two main types of . influenza viruses: types A and B. Both type A and B . influenza viruses regularly spread in people, and are . responsible for seasonal flu ...The influenza A and B virus genomes each comprise eight negative-sense, single-stranded viral RNA (vRNA) segments, while influenza C virus has a seven-segment genome. (See Table 1.) The eight segments of influenza A and B viruses (and the seven segments of influenza C virus) are numbered in order of decreasing length.Feb 24, 2022 · Influenza (flu): The flu is commonly caused by type A and B influenza strains. Symptoms are typically more severe than the common cold and can include coughing, fever (or chills), muscle aches, shortness of breath, and more. Mar 29, 2017 · Strains of influenza B are exclusively contracted by humans, while A can be carried (and spread) by animals, however, both strains are transmitted mainly by respiratory droplets from coughing and contact with an infected person. This allows strains of A to be spread more rapidly than B, while also meaning strains of B cannot cause pandemics ... The influenza virus causes flu. Influenza A, B and C are the most common types that infect people. Influenza A and B are seasonal (most people get them in the winter) and have more severe symptoms. Influenza C doesn’t cause severe symptoms and it’s not seasonal — the number of cases stays about the same throughout the year. Jul 29, 2023 · Flu symptoms tend to develop one to two days after exposure to the virus and last for between five to seven days. Day 1 to Day 3 are characterized by the abrupt onset and worsening of symptoms. Day 5 to Day 6 is when most people start to feel notably better. By Day 8, most people will have recovered and no longer be contagious. H1N1 flu is a subtype of influenza A. Subtypes of influenza A are categorized based on two proteins on the surface of the virus, hemagglutinin (H) and neuraminidase (N). There are many H and N subtypes, and each one is numbered. All H and N flu subtypes are influenza A viruses. Each influenza subtype has many different strains of influenza virus.Viral transport medium acceptable for collection of influenza specimens in 1 mL or 3 mL volumes can be used to transport swabs for COVID-19 testing. For swabs in saline: OP, NP or anterior nasal swabs may be placed in 1 to 3 mL of sterile saline (0.85 to 0.9%) in a sterile screw cap container.Dec 22, 2020 · Influenza A and B also have the same chances of complications from the flu, including a potential risk of death. (Beware of these deadly flu signs.) How are influenza A and B transmitted? Like SARS-CoV-2, the virus that causes Covid-19, both flu A and B spread from person to person, up to a distance of about six feet. Influenza (flu) is a contagious respiratory illness caused by influenza viruses that infect the nose, throat, and lungs. Some people, such as people 65 years and older, young children, and people with certain health conditions, are at higher risk of serious flu complications. There are two main types of influenza (flu) viruses: types A and B. .