Traditionally, influenza vaccines both iiv and laiv have been produced to protect against 3 different seasonal influenza viruses also called trivalent vaccines. The flu season may yet turn ugly, cdc warns the new york times. However, this type is typically less severe than type a and causes milder symptoms. Flu season is an annually recurring time period characterized by the prevalence of outbreaks of influenza flu. According to the cdc, there are three types of influenza viruses.
Most people who get sick with flu will have mild illness and will recover in. The flu, or influenza, is a highly contagious viral infection that mainly affects the respiratory system. Get an email alert every week during the flu season when the influenza report is posted. Like all inactivated influenza vaccines, these are given into the muscle. Shots made with adjuvant for people 65 years and older. Influenza b leading the charge in 2020 flu season medical. Current trends in influenza as compared to previous seasons. To lower your risk of flu, get the vaccine early and dont decide that.
Flu seasons the past few years have been particularly brutal. The start of the 20192020 flu season was unusual, with influenza b. Influenza a viruses are the only influenza viruses known to cause flu pandemics, i. Influenza disease burden estimates from the centers for disease control and prevention, including the number of influenza illnesses, medical visits, flu associated hospitalizations, and flu associated deaths that occur in the u. Most flu seasons are driven by type a viruses, the kind youve probably heard about the most. Influenza a and b are the two main types that routinely spread in humans and cause seasonal flu epidemics. Flu reports california department of public health. There have been five influenza pandemics during the last 140 years, with the 1918 spanish flu pandemic being the worst. But for the 201920 flu season, the b strain made a surprise early appearance. Influenza b strain dominating early in the 2020 flu season webmd.
Although the yearly impact of influenza varies, it affects the health of new yorkers each season. Influenza, often referred to as flu, is a contagious respiratory illness caused by influenza viruses. Elevated influenzalikeillness is likely related to covid19. Influenza, known as the flu, is a highly contagious respiratory virus. The flu season is officially underway and, while an unexpected virus is.
In virology, influenza a virus subtype h1n1 ah1n1 is the subtype of influenza a virus that was the most common cause of human influenza flu in 2009, and is associated with the 1918 flu pandemic. Type b flu only affects humans and doesnt cause pandemics. Flu report 20192020 flu season forecasts, stats, and tips. Influenzalike illness reports for this flu season red and past seasons. Cdc will continue to track influenza activity yearround as always, but as flu activity remains low, an abbreviated fluview will be published weekly during the remainder of the 20192020 season. Unusual type of flu virus is dominating early start to this years flu.
In contrast to the regular seasonal epidemics of influenza, these pandemics occur irregularly. The 2018 flu season was a pretty severe one, according to livescience, and the 2019 season is proving to be intense too. In seasons when australia has a bad flu season, the northern. Information on how these estimates are calculated can be found on cdcs. Influenza c viruses cause only mild respiratory infections and are not thought to be responsible for epidemics.
It is an orthomyxovirus that contains the glycoproteins haemagglutinin and neuraminidase. Here s what you need to know, according to experts. Human influenza a and b viruses cause seasonal epidemics of disease known as the flu season almost every winter in the united states. T he 20182019 flu season may not have been as severe as the one that came before it, but it set a record of its own, the centers for disease control and prevention cdc say. Influenza activity can sometimes be predicted and even tracked geographically. More detailed interpretation of data and more covid19 specific information can be found in covidview. Flu season thats sickened 26 million may be at its peak. Influenza b, one type of influenza virus, is dominating the 20192020 flu season early on. Updated influenza activity data will be posted on this web page every tuesday throughout the influenza surveillance season. This year s flu vaccine is not a very good match for a common strain of the flu that s especially tough on children, according to the nation s top infectious disease doctor. Type b flu can also cause seasonal outbreaks during the winter months.
Estimated influenza disease burden, by season united states, 201011 through 201819 influenza seasons. Although every flu season is different, knowing how previous flu seasons unfolded. The cdc says flu activity has picked up nationwide, with two strains now circulating. Caused by one virus, the novel 2019 coronavirus, now called severe acute respiratory syndrome coronavirus 2, or sarscov2 flu.
A brief history of the flu vaccine the weather channel. During the 20112014 seasons, flulike illnesses have typically accounted for 6% of outpatient visits at the peak of the season in the. During past seasons when vaccine viruses were antigenically like most circulating viruses, vaccine effectiveness in the range of 40% to 60% has been. This flu season has come in two waves and has been particularly hard on children, the experts said. Although you can get the flu anytime, flu season starts in october and can go as late as march and even april. The agency also tracks flulike illnesses reported in outpatient.
Us on track for one of the worst flu seasons in decades cnn. It s usually a seasonal illness, with yearly outbreaks killing hundreds of thousands of. Its symptoms are usually more serious than the sneezes and stuffy nose. Influenza, commonly known as the flu, is an infectious disease caused by an influenza virus.
Because influenza surveillance does not capture all cases of flu that occur in the u. Seasonal flu epidemics occur yearly during the colder months. This seasons flu continues to hit children and young adults particularly. Its symptoms are usually more serious than the sneezes and stuffy nose that. This flu season, health experts are mostly seeing h1n1 and h3n2 viruses. Heres what you should know about this years flu season forecast. While both the flu and covid19 may be transmitted in similar ways see the similarities section above, there is also a. This flu season is shaping up to be one of the worst in decades, according to the united states top infectious disease doctor. An influenza pandemic is an epidemic of an influenza virus that spreads on a worldwide scale and infects a large proportion of the world population. This year s flu season is shaping up to be possibly less severe than the 20172018 season, when 61,000 deaths were linked to the virus. There are four types of influenza viruses, and then subtypes of those. Information you need to know about the current 20192020 flu season.
The season started early, in october, with an unusual wave of influenza b virus. Type c influenza usually only causes mild respiratory infections. Thus far, based on limited testing data, this seasons flu shot does not look like. Yes, you can get the flu twice in one season bustle. For this reason, they are described as h1n1, h1n2 etc. Two types of influenza vaccine are widely available. Cdph obtains and analyzes clinical, and laboratory data yearround in an effort to determine the timing and impact of influenza activity and to determine how well circulating strains of the virus. Past seasons estimated influenza disease burden cdc.
What types and subtypes of influenza viruses are currently circulating. Centers for disease control and prevention cdcs influenza division. At least 14,000 people have died and 250,000 have already been hospitalized during the 20192020 flu season, according to estimates from the u. Annual influenza epidemics follow a winter seasonal pattern in the united states with typical activity peaking during late december to early february. Seasonal strains of each type of influenza mutate and change very quickly, so the flu shot is the only vaccine that needs to be continually updated. It typically spreads through respiratory droplets when a person who has. Caused by any of several different types and strains of influenza viruses transmission. However, it could equal or surpass the 20182019 seasons.
Information on how these estimates are calculated can be found on cdcs web page how cdc estimates the burden of seasonal influenza in the u. Type a and b cause the annual influenza epidemics that have up to 20% of the population sniffling, aching, coughing, and running high fevers. These symptoms typically begin two days after exposure to the virus and most last less than a week. What will the rest of the 20192020 flu season be like. Types a and b influenza are the more common forms of this infection, routinely causing seasonal outbreaks. Cumulative 20192020 season lot release status updated 7182019 flu vaccine lots that have been released by fda and are available for distribution by. The season occurs during the cold half of the year in each hemisphere. Influenza b strain dominating early in the 2020 flu season. Unusual type of flu virus is dominating early start to.
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