Swin flu virus

The H1N1 influenza virus lacks the properties associated with growth in eggs. Prior to the discovery of the H1N1 influenza virus, this particular combination of gene segments from North American and Eurasian swine had never been detected before in a single influenza virus and this new virus is different from the influenza viruses that normally circulate in North American and Eurasian pigs.

It is not known when reassortment occurred to create the H1N1 influenza virus. Testing of the virus suggests that this reassortment event may have occurred years prior to the first reports of H1N1 influenza infection in people. Pigs can be infected by influenza viruses found in birds and other animals as well as people.

Therefore, pigs represent a mixing vessel in which influenza viruses from different species can swap genes. For example, in a setting where people and animals are in close contact, pigs can be infected by influenza viruses found in pigs, poultry or humans — sometimes at the same time. However, in the late s, a series of reassortment events occurred between influenza viruses found in pigs, humans and birds.

As a result, swine influenza viruses with genes from humans, North American pigs and birds have existed in many parts of the world for around 10 years prior to H1N1 flu. This is very unlikely. Each of the gene segments within the H1N1 influenza virus have been found in pigs for more than 10 years prior to the beginning of the H1N1 influenza outbreak.

In addition, a Nature study showed that reassortment between influenza viruses found in North American and Eurasia pigs had already occurred at least once naturally in the 5 years prior to the identification of H1N1 flu.

Also, the H1N1 influenza virus does not have adaptations consistent with viruses grown in laboratories. CDC works to improve global control and prevention of seasonal and novel influenza, including swine influenza viruses, and works to improve influenza pandemic preparedness and response. CDC has partnered with the U. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Influenza Flu.

Section Navigation. The H3N2 viruses initially were introduced into the pig population from humans. However, since then the H3N2 viruses circulating in pigs have changed. The H3N2 viruses circulating in pigs now are very different from the seasonal H3N2 viruses that circulate in humans. Just as there are influenza vaccines for people, there are specific swine influenza vaccines available for pigs. Skip directly to site content Skip directly to page options Skip directly to A-Z link. Influenza Flu.

Section Navigation. Facebook Twitter LinkedIn Syndicate. Minus Related Pages. On This Page. Each year's seasonal flu vaccine protects against the three or four influenza viruses that are expected to be the most common during that year's flu season. The flu vaccine can reduce your risk of the flu and its severity and lower the risk of having serious illness from the flu and needing to stay in the hospital.

Flu vaccination is especially important in the flu season because the flu and coronavirus disease COVID cause similar symptoms. Preventing the flu and reducing the severity of flu illness and hospitalizations could also lessen the number of people needing to stay in the hospital. The flu vaccine is available as an injection and as a nasal spray.

The nasal spray is approved for use in healthy people ages 2 through 49 years old. The nasal spray isn't recommended for some groups, such as pregnant women, children between 2 and 4 years old with asthma or wheezing, and people who have compromised immune systems. For example, you may need to practice social distancing physical distancing and stay at least 6 feet 2 meters from others outside your household.

You may also need to wear a cloth face mask when around people outside your household. Mayo Clinic does not endorse companies or products. Advertising revenue supports our not-for-profit mission. Check out these best-sellers and special offers on books and newsletters from Mayo Clinic Press. This content does not have an English version.

This content does not have an Arabic version. Overview The H1N1 flu, commonly known as swine flu, is primarily caused by the H1N1 strain of the flu influenza virus.

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