The H1N1 flu, commonly known as swine flu, spread around the globe faster than any virus in history, largely due to air travel. Pandemic flu strains are of deep concern because there is no or only limited natural immunity to novel flu strains, and therefore nearly everyone is susceptible to infection. A high percentage of the population could become ill at any one time and overwhelm public health systems, and a large number of deaths could occur.
We were very fortunate in the case of the H1N1 pandemic. Most people suffered only a mild illness. H1N1 was not an especially virulent virus. Further, the virus remained stable and did not mutate to a more deadly form or to a drug resistant form.
Other influenza strains have been far more lethal. Currently, there is concern about the new avian H7N9 virus. Most patients have experienced severe respiratory illness, with about one-third of the cases resulting in death. Although the virus does not appear to pass easily from person to person, there is always the worry that it could mutate into a form that is more transmissible.
There are drugs that are effective against influenza, but the possibility that a virus could acquire resistance to the drugs is a serious issue. There are four different antiviral drugs, of two different classes, that are effective against influenza. However, influenza viruses can and do develop resistance to these drugs - as one of the main circulating seasonal viruses did during a recent flu season - so that the drugs can no longer be used to treat or prevent infections.
There is a need to develop additional drugs that can prevent or alleviate flu symptoms. Vaccines can be developed to protect humans from influenza viruses. However, as was strikingly obvious during the H1N1 pandemic, vaccine production takes many months.
By the time a vaccine was developed, tested, produced, and distributed, many individuals had already been infected. Clearly, a more rapid method of vaccine development is needed. The goal of developing a universal flu vaccine, one that would provide durable protection against multiple flu strains, remains a challenging feat. The greatest fear is that a new pandemic influenza virus could emerge that could pass from person to person as easily as the H1N1 virus, but be as deadly as the H5N1 virus.
Additional concerns are that an influenza virus could mutate into a form that would be resistant to anti-influenza drugs, such as Tamiflu, or that the virus could change so that a vaccine no longer afforded protection. Even though the H1N1 pandemic was relatively mild, knowing how lethal and unpredictable influenza viruses can be, we must continue to remain alert and prepare for future pandemics. Investigators in the Department of Molecular Virology and Microbiology MVM have been studying influenza for several decades, with an Influenza Research Center first established in A major focus of the work is directed towards the development and testing of influenza vaccines to find the most effective vaccination dosages, methods, and strategies to protect the population against this deadly disease.
Other projects involve studying the structure and function of important influenza proteins. Research is ongoing on both epidemic influenza also referred to as seasonal or interpandemic influenza and pandemic influenza. Epidemic influenza occurs annually and is attributable to minor changes in genes that encode proteins on the surface of circulating influenza viruses.
Pandemic influenza occurs when more significant changes in the influenza A virus arise as a result of the acquisition of genes from influenza viruses of other animal species by a human virus strain, thus creating a novel virus. The latter carries a greater risk for the human population. It was previously led by Dr. Wendy Keitel and is currently under the direction of Dr. Hana El-Sahly. The VTEU network conducts clinical trials that evaluate vaccines and treatments for a wide array of infectious diseases.
An important strength of this established network is that it is able to efficiently and safely test new vaccines within a rapid time frame. The VTEU research group in the department has been involved in important studies that led to the licensure of live attenuated and high dose inactivated influenza virus vaccines.
They have tested vaccines to seasonal influenza and they have performed many studies evaluating vaccines targeting pandemic influenza, including the swine-origin H1N1, and the H5N1, H9N2, and H7N9 viruses, among others.
They have evaluated methods to improve vaccine immunogenicity, including delivery of vaccine by different routes of administration, different dosages, and with different adjuvant preparations.
Researchers involved in these studies include Drs. Their hope is that the results of these studies will identify the optimal and most effective dosages of vaccine to protect the public from seasonal influenza, as well as from a possible influenza pandemic. MVM investigators would like to better understand epidemic influenza seasonal flu infections, disease, and vaccines with the goal of developing ways to better control these epidemics.
Towards this goal, they are working on developing new improved vaccines against epidemic influenza strains and are trying to understand how the immune systems of different people respond to the influenza virus and influenza vaccines. In addition, MVM researchers with the VTEU have been evaluating the safety and immunogenicity of seasonal influenza vaccine in pregnant women.
Because pregnant women are at higher risk for serious complications from the flu, it is important to develop strategies to protect these women from seasonal and pandemic influenza. The clinical trial includes up to women recruited from nine sites across the nation and is headed by Dr. Shital Patel. It is one of the few studies that will evaluate antibody responses in pregnant women following vaccination. Evaluating the safety of seasonal inactivated influenza vaccine will yield vital information in anticipation of the need to test novel vaccines against possible future pandemic strains, in pregnant women.
Scientists are also conducting a study in collaboration with Kelsey-Seybold Clinics to determine the effectiveness of an inactivated influenza vaccine in protecting pregnant women and whether these immunized women can pass immunity against influenza to their infants, so that newborns would be protected from influenza during their first few months of life. Another approach to protect against influenza epidemics is called herd immunity. The idea is to vaccinate a large percentage of school-age children to limit the spread of influenza without needing to vaccinate a larger percentage of the general population.
The reasoning behind this idea is that school-age children are often the source of infection and pass the virus onto their friends, teachers, and family members. This might be especially helpful to the elderly population who are at higher risk from influenza-related complications and whose immune systems may not mount as effective a response to influenza as younger individuals. Another advantage to this approach is that it might be possible to achieve high community protection from influenza with a limiting amount of vaccine.
Pedro Tony Piedra and colleagues are testing herd immunization in school-aged children in central Texas. In their initial study, they found that vaccination of 12 to 15 percent of children in selected communities resulted in an indirect protection to influenza infection in 8 to 18 percent of the adults in these communities. They are currently conducting a larger, school-based vaccination program with the goal of immunizing 50 percent of the children, and they will determine how effective this level of immunization is in preventing infection in adults.
Piedra and co-workers want to know how many children need to be vaccinated in order to protect the adult population from influenza infection, and they would like to use this approach to control the spread of epidemic influenza.
They also hope to use this approach as a model for combating pandemic influenza and bioterrorism. Piedra has also investigated the effects of oseltamivir commonly known as Tamiflu on influenza-related complications in children with chronic medical conditions. Patients with underlying medical conditions are at higher risk of complications from both seasonal and pandemic flu.
Piedra and his colleagues found that children with chronic medical conditions benefit from the use of Tamiflu if it is prescribed early in the disease process. Children and adolescents between the ages of 1 and 17 who were at high risk of influenza complications showed significant reductions in the risks of respiratory illnesses other than pneumonia, reduced risk of otitis media a middle ear infection , and fewer hospitalizations in the 14 days after influenza diagnosis.
The most effective way to prevent the widespread infection and high mortality rate that a new influenza virus could inflict upon the human population would be to vaccinate people, so that the human immune system would be prepared to fight off an infection. MVM investigators are trying to identify the best way to prime the human immune system to defend against flu strains that could cause a pandemic.
Researchers have been testing vaccines against H1N1, H5N1, H7N9, and other potential pandemic flu strains and analyzing the immune responses of different people to the vaccines. Members of the Department were part of the national effort to prepare a vaccine against H1N1 influenza and test candidate vaccines. Several different parameters were tested: the number of doses required one or two , different dosage amounts 15 or 30 micrograms , and different age groups 18 to 64 years old, age 65 and older, and healthy children.
The goal was to determine the reactions and antibody protection responses following immunization with experimental influenza H1N1 vaccine when given with seasonal influenza vaccine. Overview The H1N1 flu, commonly known as swine flu, is primarily caused by the H1N1 strain of the flu influenza virus. More Information Self-care for the flu. Request an Appointment at Mayo Clinic.
More Information He's the bravest kid I've ever seen. More Information Flu masks Flu vaccine: Safe for people with egg allergy? Share on: Facebook Twitter. Show references Key facts about human infections with variant viruses. Centers for Disease Control and Prevention. Accessed Jan. Dolin R. Epidemiology of influenza.
Grohskopf LA, et al. Prevention and control of seasonal influenza with vaccines: Recommendations of the Advisory Committee on Immunization Practices — United States, influenza season. Cohen J, et al. Influenza viruses. In: Infectious Diseases. Philadelphia, Pa. Accessed Nov. Flu: What to do if you get sick. If soap and water are not available and alcohol-based products are not allowed, other hand sanitizers that do not contain alcohol may be useful.
Germs can be spread when a person touches something that is contaminated with germs and then touches his or her eyes, nose, or mouth. Droplets from a cough or sneeze of an infected person move through the air. Germs can be spread when a person touches respiratory droplets from another person on a surface like a desk, for example, and then touches their own eyes, mouth or nose before washing their hands.
To prevent the spread of influenza virus, it is recommended that tissues and other disposable items used by an infected person be thrown in the trash. Additionally, persons should wash their hands with soap and water after touching used tissues and similar waste. To prevent the spread of influenza virus it is important to keep surfaces especially bedside tables, surfaces in the bathroom, kitchen counters and toys for children clean by wiping them down with a household disinfectant according to directions on the product label.
Linens, eating utensils, and dishes belonging to those who are sick do not need to be cleaned separately, but importantly these items should not be shared without washing thoroughly first.
Linens such as bed sheets and towels should be washed by using household laundry soap and tumbled dry on a hot setting. Individuals should avoid "hugging" laundry prior to washing it to prevent contaminating themselves. Individuals should wash their hands with soap and water or alcohol-based hand rub immediately after handling dirty laundry.
You cannot get infected with HIN1 from eating pork or pork products. Eating properly handled and cooked pork products is safe. Tap water that has been treated by conventional disinfection processes does not likely pose a risk for transmission of influenza viruses. Current drinking water treatment regulations provide a high degree of protection from viruses. No research has been completed on the susceptibility of H1N1 flu virus to conventional drinking water treatment processes.
However, recent studies have demonstrated that free chlorine levels typically used in drinking water treatment are adequate to inactivate highly pathogenic H5N1 avian influenza.
It is likely that other influenza viruses such as H1N1 would also be similarly inactivated by chlorination. To date, there have been no documented human cases of influenza caused by exposure to influenza-contaminated drinking water. Influenza viruses infect the human upper respiratory tract. There has never been a documented case of influenza virus infection associated with water exposure. Recreational water that has been treated at CDC recommended disinfectant levels does not likely pose a risk for transmission of influenza viruses.
No research has been completed on the susceptibility of H1N1 influenza virus to chlorine and other disinfectants used in swimming pools, spas, water parks, interactive fountains, and other treated recreational venues. It is likely that other influenza viruses such as H1N1 virus would also be similarly disinfected by chlorine. Yes, recreational water venues are no different than any other group setting.
The spread of this H1N1 flu is thought to be happening in the same way that seasonal flu spreads. Flu viruses are spread mainly from person to person through coughing or sneezing of people with influenza. Sometimes people may become infected by touching something with flu viruses on it and then touching their mouth or nose. In addition to humans, live swine and turkeys, a small number of ferrets which are highly susceptible to influenza A viruses , domestic cats and dogs have been infected with H1N1 virus.
In addition, H1N1 virus infection was reported in a cheetah in the United States. CDC is working closely with domestic and international public and animal health partners to continually monitor reports of H1N1 in animals and will provide additional information to the public as it becomes available.
Pet ferrets with naturally occurring H1N1 infection have exhibited illness similar in severity to that seen in ferrets exposed to seasonal influenza viruses and to H1N1 virus in laboratory settings. H1N1 was also very serious for pregnant women.
Frequently Asked Questions Is the swine flu caused by bacteria? Who is at greater risk of complications from the swine flu? What caused the swine flu pandemic? How can you prevent H1N1? Was this page helpful? Thanks for your feedback! Sign Up. What are your concerns? Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles.
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