Influenza ( Flu ) Virus
Influenza, better known as flu, is an infectious disease caused by RNA viruses of the family Orthomyxoviridae (influenza virus), which attacks birds and mammals. The most common symptoms of this disease are chills, fever, sore throat, muscle aches, severe headache, coughing, weakness and general discomfort.
Although often confused with other influenza-like illness, especially colds, influenza is a disease more severe than the flu and is caused by different types of viruses Influenza can cause nausea, and vomiting, especially in children, but the symptoms The disease is more frequently found in gastroenteritis, which is completely unrelated, which is also sometimes incorrectly referred to as "stomach flu." Influenza viral pneumonia can sometimes lead to direct or cause secondary bacterial pneumonia.
Typically, influenza is transmitted through the air via coughing or sneezing, which will generate aerosols containing the virus. Influenza can also be transmitted through direct contact with bird feces or nasal mucus, or through contact with contaminated surfaces. Airborne aerosols (airborne aerosols) suspected cause most infections, although the transmission path where the greatest role in a disease is not yet completely clear. The influenza virus can be inactivated by sunlight, disinfectant, and detergent. Frequent hand washing will reduce the risk of infection because the virus can be inactivated with soap.
Influenza spreads throughout the world in seasonal epidemics, resulting in the death of 250,000 and 500,000 people each year, even up to millions of people in pandemic years. On average 41,400 people die each year in the United States in the period between 1979 and 2001 because of influenza. In 2010 the Center for Disease Control and Prevention in the United States changed the way they reported the estimate of deaths due to influenza in 30 years. Today they report that there is a range of mortality rates ranging from 3300 to 49,000 deaths per year.
Three influenza pandemics occurred in the twentieth century and has killed tens of millions of people. Each pandemic was caused by the emergence of new strains of this virus in humans. Often, this occurs when a new strain of flu virus that already have spread to humans from another animal species, or when a human influenza virus strains that have been there to take new genes from viruses that normally infect poultry or pork. Avian strain called H5N1 has raised fears the emergence of new influenza pandemic, after its emergence in Asia in the 1990s, but the virus has not evolved into a form that spreads easily from human to human. In April 2009 a strain of virus The new flu evolved that contain a mixture of genes from human influenza, swine, and poultry, which was originally called "swine flu" and is also known as influenza A/H1N1, which appeared in Mexico, the United States, and several other countries. World Health Organization (WHO) officially declared the pandemic a pandemic on June 11, 2009 (see the 2009 flu pandemic). WHO Declaration on the pandemic level 6 is an indication of the spread of the virus, rather than the severity of the disease, these strains actually have a lower mortality rate compared with the common cold virus outbreak.
Vaccinations against influenza are usually available for people in developing countries. Cattle are often vaccinated poultry to prevent the destruction of all cattle. The vaccine in humans is most often used is the trivalent influenza vaccine (trivalent influenza vaccine [TIV]) that contain antigens that have been purified and inactivated against three strains of virus. Usually, this kind of vaccine contains material from two strains of influenza virus subtypes A and one strain of influenza subtype B. TIV has no risk of transmitting the disease, and has a very low reactivity. Vaccine formulated for one year may be ineffective for the following year, since influenza viruses evolve rapidly, and new strains will soon replace old strains. Antiviral drugs can be used to treat influenza, neuraminidase inhibitors (such as Tamiflu or Relenza). which is especially effective.
Classification
The types of virus
In the classification of viruses, including influenza virus RNA viruses which are three of the five genera in the family Oethomyxoviridae:
* Influenza A Virus
* Influenza B Virus
* Influenza virus C
These viruses have a much kinship with human parainfluenza virus, which is an RNA virus that is part of the paramyxovirus family, which is a common cause of respiratory infections in children, such as croup (laryngotracheobronchitis), but can also cause disease similar to influenza in adults.
Influenza A virus
This genus has one species, influenza virus A. Wild aquatic birds are natural hosts for a large number of varieties of influenza A. Sometimes, the virus can be transmitted to other species and can cause outbreaks that have a major impact on domestic poultry or pose a human influenza pandemic.
Virus type A is the most virulent human pathogens among the three types of influenza and cause the most severe disease. Influenza A virus can be further divided into subdivisions of different serotypes, serotypes based on antibody responses against this virus. serotype that has been confirmed in humans, sorted by the number of deaths pandemic in humans, are:
* H1N1, which caused the Spanish Flu in 1918, and the Swine Flu in 2009
* H2N2, which caused the Asian Flu in 1957
* H3N2, which caused Hong Kong Flu in 1968
* H5N1, which caused AI in 2004
* H7N7, which has unusual zoonotic potential
* H1N2, endemic in humans, pigs, and poultry
* H9N2
* H7N2
* H7N3
* H10N7
Influenza B virus
This genus has one species, namely influenza virus B. influenza B almost exclusively only attack humans and more rarely as compared with influenza A. Other animals known to be infected by influenza B infection is the seal and ferrets. This type of influenza mutate 2-3 times slower than type A and therefore less genetic diversity, there is only one serotypes of influenza B. Because there is no antigenic diversity, some degree of immunity to influenza B is usually acquired at a young age. However, mutations that occur in influenza B virus is enough to make permanent immunity becomes impossible. Changes are slow antigen, combined with a limited number of host (does not allow transfer of antigens between species), create a pandemic influenza B does not occur.
Influenza C virus
This genus has one species, influenza C virus, which infects humans, dogs, and pigs, sometimes causing severe illness and local epidemics. However, influenza C is less common than with other species and usually cause only mild disease in children.
Structure, properties, and nomenclature subtypes
Influenza virus A, B, and C are very similar in overall structure. This virus particle diameter and typically 80-120 nanometers or less shaped like a ball, although filamentous forms can be found. The form of this filamentous more common in influenza C, which can form thread-like structure with a length of 500 micrometers on the surface of infected cells. However, although a variety of shapes, particles of all influenza viruses have the same composition. The composition is a viral envelope containing two types of glycoproteins, that surrounds a central core. The central core containing the RNA genome and other viral proteins that encloses and protects the RNA. RNA tends to consist of a single strand but in special cases can be two strands. In the virus, the viral genome does not consist of a nucleic acid sequence; but usually consist of seven or eight negative-sense RNA of the segmented, each part containing one or two RNA genes. Example, the genome of influenza A contains 11 genes in eight sections of RNA, which code 11 proteins: hemagglutinin (HA), neuraminidase (NA), nucleoprotein (NP), M1, M2, NS1, NS2 (NEP: nuclear export protein), PA, PB1 (polymerase basic 1 ), and PB2 PB1-F2.
Hemagglutinin (HA) and neuraminidase (NA) are two major flikoprotein outside viral particles. HA is a lectin that mediates bonding (binding) virus to target cells and entry of the viral genome in target cells, while NA is involved in the escape of child virus from infected cells, by cleaving sugars that bind to mature virus particles. Therefore, this protein is a target for antiviral drugs.And again, both an antigen, whereby antibodies to these antigens can be created. Influenza A viruses are classified into subtypes based on antibody responses against HA and NA. The types of HA and NA is a distinction in the H and N, the naming of viruses, such as H5N1. There are 16 H subtypes and 9 N subtypes are known, but only H 1, 2, and 3, and N 1 and 2 are commonly found in humans.
Replication
The virus can replicate only in living cells. Infection and replication of influenza is a gradual process: first, the virus must bind to the cell and enters the cell, then move the genome in a place where the virus can produce a duplicate of viral proteins and RNA, and then compile these components into new virus particles, and finally, exit from the host cell.
Influenza virus hemagglutinin binds to sugar through acid sialat on the surface of epithelial cells, usually on the nose, throat, and lungs of mammals, birds and intestine (stage 1 in the figure of infection). After the hemagglutinin broken down by protease, the virus would enter cells through endocytosis.
Once inside the cell, acidic conditions in endosom will cause the two events occur: first, part of the hemagglutinin protein would unite the viral envelope with the vacuole membrane, then the M2 ion channel will allow protons to move through the viral envelope and acidify the virus core, which will cause decompose and release the core into viral RNA and core protein. The molecule of viral RNA (vRNA), accessory proteins, and RNA-dependent RNA polymerase (RNA-dependent RNA polymerase) will be released in the cytoplasm (Phase 2). M2 ion channel will be partitioned (blocked) by the drug amantadine, which will prevent infection. [46]
This core protein along with vRNA to form a complex that will be transported to the cell nucleus, where RNA-dependent RNA polymerase to initiate transcription of complementary sense vRNA positive (step 3a and b). vRNA can run out into the cytoplasm and translation (step 4) or remained in the nucleus. Newly synthesized viral proteins can be secreted through the Golgi apparatus to the cell surface (in the neuraminidase and hemagglutinin, step 5b) or transported back into the cell nucleus to bind vRNA and form new viral genome particles (step 5a). Other viral proteins have a diverse work in the host cell, including cellular mRNA parse and use the free nucleotides for vRNA synthesis and also inhibit translation of mRNA and also inhibits host cell mRNA translation.
negative-sense vRNA that form of candidate viral genomes, RNA-dependent RNA polymerase (RNA-dependent RNA polymerase), and other viral proteins are organized into virions. Hemagglutinin and neuraminidase molecules will be grouped to form a bulge on the cell surface. vRNA and viral core protein will leave the cell nucleus and enter this membrane protrusion (step 6). Virus budding adults will do off of the cells in a spherical shape that consists of host phospholipid membrane, acquiring hemagglutinin and neuraminidase are contained in a layer of this membrane (step 7). As before, the virus will bind through hemagglutinin; mature virus neuraminidase will break away if they've broken sialat acid residues from the host cell. Drugs that inhibit neuraminidase, such as oseltamivir, would prevent the release of new infectious virus and prevent viral replication. After the release of a new influenza virus, the host cell will die.
Because of the absence of RNA proofreading enzymes, RNA-dependent RNA polymerase is copying the virus genome will make a mistake about every 10 thousand nucleotides, which corresponds to an average of influenza vRNA. Therefore, most of the influenza virus is a mutant finished assembled; this will cause antigen, which is a slow change in the antigen on the surface of the virus over time. The separation of the genome into eight separate segments of vRNA allows mixing or reassortment of vRNA if more than one type of influenza viruses infect a single cell. This will lead to rapid changes of genetic virus that will cause displacement antigen, which is an abrupt change from one antigen to other antigens. The big change that suddenly allows the virus to infect new host species and can be quickly overcome protective immunity that has been there. This is important in the emergence pandem mechanism, which is discussed below in the section of Epidemiology.
Signs and symptoms
Symptoms of influenza can be started quickly, one to two days after infection. Usually the first symptoms are chills or feeling cold, but fever is also common in early infection, with body temperatures ranging from 38-39 ° C (approximately 100-103 ° F). Many people feel so ill that they can not get out of bed occupied for several days, with aches and pains all over his body, which feels heavier in the hip area and legs. Symptoms of influenza may include:
* Fever and a feeling of extreme cold (shivering, shaking)
* Cough
* Nasal obstruction
* Body aches, especially joints and throat
* Fatigue
* Headache
* Eye irritation, watery eyes
* Red eyes, red skin (especially face), as well as redness of the mouth, throat, and nose
* Rash petechiae
* In children, gastrointestinal symptoms such as diarrhea and abdominal pain, (may be severe in children with influenza B)
Sometimes it is difficult to distinguish between colds and influenza in the early stages of this infection, but the flu can be identified if there are sudden high fever with extreme fatigue. Diarrhea is usually not a symptom of influenza of children, but it can be found in most cases of "bird flu" H5N1 in humans and can be a symptom in children. The most common symptoms of influenza found on the indicated on the table at right.
Because antiviral drugs effective in treating influenza when given early (see treatment section below), it is important to identify cases early. Of the symptoms mentioned above, the combination of fever with cough, sore throat and / or nasal congestion may improve the accuracy diagnostic.Two studies of decision analysis showed that when there is a local influenza outbreak, the prevalence is more than 70%, therefore, patients with one combination of these symptoms can be treated with neuraminidase inhibitors without examination. Even when the absence of local outbreaks, treatment can be justified in older patients during the influenza season during the prevalence is over 15%.
The availability of laboratory tests for influenza is constantly increasing. Center for Disease Control and Prevention (CDC) United States, summarizes the latest available laboratory tests. According to the CDC, rapid diagnostic tests (rapid diagnostic test) has a sensitivity of 70-75% and specificity of 90-95% compared with viral culture . This examination is particularly useful in the influenza season (prevalence = 25%) in the absence of outbreaks, or periinfluenza season (prevalence = 10% [60]).
Transmission
Influenza virus shedding (the time at which a person can transmit the virus to others) starting one day before symptoms appear and the virus will be released for between 5 to 7 days, although some people may shed virus for longer periods. People who are infected with influenza the most infective in the second and third day after infection. The number of viruses that are released seemingly associated with fever, the amount of virus released is greater when the temperature is higher. Children are far more infectious than adults and they shed virus before they experience symptoms until two weeks after infection. Transmission of influenza can be modeled mathematically, which will assist in the prediction of how the virus spreads in the population.
Influenza can be spread in three main ways: through direct transmission (when an infected person sneezing, nasal mucus which there enter directly in the eyes, nose, and mouth of another person); through the air (when a person inhaling aerosols (small liquid droplets in air) produced when an infected person coughs, sneezes, or spits), and through the introduction of hand-to-eye, hand-to-nose, or hand-to-mouth, either from contaminated surfaces or from direct personal contact such as shaking hands. Where the most important mode of transmission remains unclear, but all have contributed in the spread of the virus. In the air routes of transmission, droplet size is small enough to be inhaled in diameter from 0.5 to 5 μm and inhalation of droplets may be sufficient to cause infection.Although a single sneeze can release up to 40,000 droplets, most of the droplets are quite large and will quickly disappear from the air. How long does the influenza virus can survive in air droplets appears to be influenced by moisture content and ultraviolet radiation: low humidity and lack of sunlight in the winter to help the survival of this virus.
Because the influenza virus can survive outside the body, this virus can be transmitted through contaminated surfaces such as sheets of money, doorknobs, light switches, and objects other household. The length of time the virus can survive on a surface diverse, the virus can survive for a day or two on a hard surface and not porous such as plastic or metal, for about fifteen minutes on dry tissue paper, and only five minutes on the skin. However, when the virus contained in the mucous / mucus, mucus can protect the viruses so that endure for a long time (up to 17 days on banknotes). The bird flu virus can survive in an unknown time when in a frozen state. The virus has inactivation by heating to 56 ° C (133 ° F) for a minimum of 60 minutes, and also by acid (pH <2).
Pathophysiology
The mechanism of how infection can cause symptoms of influenza in humans have been studied intensively. One mechanism is the inhibition is believed to adrenocorticotropic hormone (ACTH / Adrenocorticotropic Hormone) that cause decreased levels of the hormone cortisol. Knowing which genes are contained in certain viral strains can help predict how the virus can be transmitted infection and weighing what will happen (predicting the pathophysiology of a viral strain).
For example, part of the process that allows the influenza virus invades a cell is the decomposition of the virus hemagglutinin protein by one of the human protease enzymes. on a mild viral infection and avirulen, the structure of hemagglutinin that there can only be parsed by the proteases that are found in throat and lungs, so the virus can not infect other tissues. However, at the very virulent strain, like H5N1, the hemagglutinin is contained within the virus can be parsed by a variety of diverse proteases, thereby allowing the virus spreads throughout the body.
Virus hemagglutinin protein responsible for both in determining which species can be infected by a virus strain and the location of the respiratory tract which can bind to an influenza virus strain. strain can be transmitted easily from human to human has the hemagglutinin protein that binds to receptors in the upper respiratory tract, such as the nose, throat, and mouth. Conversely, a highly dangerous H5N1 strain binds to the receptor most commonly found in the lung. Differences in the site of infection may be part of the reason why the H5N1 strain caused severe viral pneumonia in the lungs, but does not spread easily through coughing and sneezing.
Symptoms are often found on the flu such as fever, headache, and fatigue is the result of a large number of proinflammatory cytokines and chemokin (such as interferon or tumor necrosis factor (TNF)) that is produced by cells infected with influenza. Unlike rhinovirus that causes colds (common cold / cold), influenza cause tissue damage, so symptoms that occur are not entirely caused by the inflammatory response. The immune response is large this can lead to "cytokine storm" which can be life threatening. This incident allegedly the cause of unusual mortality in both the H5N1 bird flu, and the 1918 pandemic strain. However, another possibility is a large number of cytokines produced only a result of viral replication is very large caused by these strains, and the immune response does not contribute to the disease.
Prevention
Vaccination
Vaccination against influenza with influenza vaccine is often recommended in high risk groups, such as children and the elderly, or in patients with asthma, diabetes, heart disease, or people who have immune disorders. The influenza vaccine can be produced in several ways: the most common ways is by growing the virus in fertilized chicken eggs. Once purified, the virus will then be activated (eg, with detergent) to produce an inactivated virus vaccine. Alternatively, the virus can be grown in eggs until loss of virulence virus avirulen then given as a live vaccine. The effectiveness of influenza vaccines varies. Because the viral mutation rate is very high, given the influenza vaccine usually provides protection for no more than a few days. Each year, the WHO predicts that virus strains which are most likely to circulate in the next year, allowing pharmaceutical companies to develop vaccines that will provide the best immunity against these strains. The vaccine has also been developed to protect poultry from bird flu. This vaccine can be effective against some strains and used both as a preventive strategy, or combined with culling (breeding) in an effort to wipe out the plague.
There are likely to get influenza despite being vaccinated. The vaccine will be reformulated each season for specific strains of flu but can not cover all strains actively infecting people in the entire season. It takes six months for manufacturers to formulate and produce millions of doses needed to deal with seasonal epidemics; sometimes, a new strain or strains that are not thought to stand at a particular time and infect people even though they have been vaccinated (as happened in Fujian Flu H3N2 flu season 2003-2004). There is also a possibility of getting an infection before vaccination and became sick by the strain that should be prevented by vaccination, because the vaccine takes two weeks before it becomes effective.
In the 2006-2007 season, the first time the CDC recommends that children aged less than 59 months to receive an annual influenza vaccine. Vaccines can cause the immune system to react when the body receives the actual infection, and symptoms of generalized infection (a lot of colds and flu symptoms are just general infection symptoms) can appear, even though the symptoms are usually not as heavy or lasts for influenza. The most dangerous side effects are severe allergic reaction to either the viral material and residue from chicken egg used to grow the influenza virus; but the reaction is very rare.
In addition to vaccination against seasonal influenza, researchers sought to develop a vaccine against pandemic influenza. The development, production, and distribution of pandemic vaccines that can quickly influenza save the lives of millions of people in the event of a pandemic influenza. Because there is only a short time between the identification of pandemic strains and vaccination requirements, researchers are looking for options other than modes of production of vaccines through the egg. An inactivated live vaccine technologies (egg-based or cell-based), and recombinant technologies (proteins and virus-like particles), will provide real time access to better and can be produced with a more affordable, thereby increasing access for people who live in the country -medium and low income countries, where the likelihood of a pandemic comes. Until July 2009, more than 70 clinical trials that are known to have been implemented or are being implemented regarding pandemic influenza vaccine. In September 2009, the United States Food and Drug Agency approved the four vaccine against the H1N1 2009 influenza virus (pandemic strain at the time), and asked stocks of vaccine are available in the next month.
Infection control
Effective way to reduce influenza transmission among them is the personal hygiene and good hygienic habits: such as not touching the eyes, nose and mouth; frequent hand washing (with water and soap, or with alcohol-based wash liquid); shut your mouth and nose when coughing and sneezing, avoid close contact with sick people, and remain at home while being sick. No spitting is also recommended. Although the face mask can help prevent transmission when caring for a sick person there is conflicting evidence regarding the benefits of this on society. Smoking increases the risk of transmission of influenza, and also cause more severe disease symptoms.
Since influenza spreads through aerosols and contact with contaminated surfaces, surface cleaning can help prevent some of the infection. Alcohol is a sanitary materials that are effective against influenza viruses, while quaternary ammonium compounds can be used in conjunction with sanitation so that the effects of alcohol may persist longer. At the hospital, quaternary ammonium compounds and bleach used to clean the room and equipment previously used by patients with symptoms of influenza. At home, it can be done effectively by using a diluted chlorine bleach.
In the last pandemic, closure of schools, churches, and theaters to slow the spread of the virus but do not have a major impact on overall mortality. Not to be ascertained whether the decrease of public meetings, for example by closing schools and workplaces, would reduce transmission because the people who suffer from influenza could still move from one place to another; such an approach will also be difficult to do and may not be preferable. If a small number of people develop an infection, isolating people who are sick can reduce the risk of transmission .
Treatment
People suffering from the flu are advised to get plenty of rest, drink plenty of fluids, avoiding alcohol and tobacco use, and where necessary, taking medications such as acetaminophen (paracetamol) to relieve symptoms of fever and muscle aches associated with flu. Children and teenagers with flu symptoms (particularly fever) should avoid use of aspirin during influenza infection (especially influenza type B), because it can cause Reye's Syndrome, a rare liver disease but has a potential cause of death. Since influenza is caused by a virus, antibiotics have no effect on infection; unless given for secondary infections like bacterial pneumonia. Antiviral treatment can be effective, but some strains can influenza showed resistance to the standard antiviral drugs.
Two classes of antiviral drugs used against influenza is a neuraminidase inhibitor and M2 protein inhibitors (adamantane derivatives). Neuraminidase inhibitors is currently preferred to viral infections because less toxic and more effective. The CDC recommends not to use the M2 inhibitors on the influenza season 2005-06 as height levels of drug resistance. Because women seem to be affected hamila more large compared with the general population by the 2009 H1N1 influenza virus, immediate treatment with anti-influenza drugs has been recommended. At a Press Conference November 2009 influenza H1N1, WHO recommends that people at high risk groups, including pregnant women, children aged less than two years old and people with respiratory problems, in order to begin taking antiviral medications as soon as they are experiencing symptoms of flu. antivirus Drugs used include oseltamivir (Tamiflu) and zanamivir (Relenza).
Prognosis
Effect of influenza is much more severe and last longer than a cold. Most people will recover on its own within one to two weeks, but others will experience life-threatening complications (like pneumonia). Influenza can be deadly, especially in people who are weak, young and old, or have a chronic illness. People with weak immune systems, such as people with advanced HIV infection or transplant recipient patients (whose immune systems suppressed with drugs to prevent rejection of organ transplants), suffered more severe disease. other high risk groups are pregnant women and small children.
Influenza can worsen chronic health problems. People with emphysema, chronic bronchitis or asthma can have trouble breathing when they have flu, and influenza can lead to worsening of coronary heart disease or congestive failure hanging. Smoking is another risk factor associated with more severe disease and mortality higher caused by influenza.
According to WHO: "Every winter, tens of millions of people exposed to flu. Most just sick and does not work for one week, while the elderly have a higher risk of death from this disease. We know that the victim died worldwide exceed hundreds of thousands of people each year, but even in developed countries, this amount can not be ascertained, because the medical authorities do not usually verify who died from influenza and people who died with flu-like-illness . Even healthy people can be affected, and serious problems posed by influenza can occur at any age. People aged over 50 years old, very young children, and people of all ages with chronic medical conditions are more likely to get complications from influenza, such as pneumonia, bronchitis, sinus and ear infections.
In some cases, autoimmune responses against influenza may contribute to Guillain-Barré syndrome (GBS). However, because many other infections that may increase the risk of this disease, influenza is a cause that is important only in the event of an epidemic. This syndrome has been trusted as well as a rare side effect of influenza vaccine. Although one study reports give incidence of one case per one million vaccinations, a large study in China, reported in NEJM, which covers nearly 100 million doses of vaccine against influenza "flu" H1N1 in 2009 found only eleven cases of Guillain-Barré syndrome, (0.1%) of the total incidence in people who are vaccinated, they are more low of disease incidence rates in China, and there are no side effects were found; "risk-benefit ratio, which is commonly applied to vaccines and everything in medical treatment, very much skewed to the use of vaccines. " Getting the influenza infection itself increases the risk of death (up to 1 in 10,000) and increase the risk of GBS to levels higher than those posed by the use of vaccine (approximately 10 times the use of current estimates this).
Research
Research on influenza includes research in molecular virology, how viruses cause disease (pathogenesis), the host immune response, viral genome, and how the virus spread (epidemiology). This research helps the development of measures to ward off influenza; for example, a better understanding of the body's immune system response vaccine help development, and a detailed description of how influenza attack the cells to help the development of antiviral drugs. One of the basic research program of the most important is the Influenza Genome Sequencing Project (Project determination of influenza genome sequence), which created a library (a collection list) sequences (genes) influenza; this library can help determine which factors make one strain more lethal than the strains that another, which genes are most affecting the immunogenicity, and how the virus evolved over time.
The new vaccine research is very important, because currently available vaccines in very slow and expensive to produce and must be reformulated each year. Determination of the sequence (sequencing) of the influenza genome and recombinant DNA technology can accelerate the discovery of new vaccine strains by allowing researchers to replace a new antigen in the vaccine strains that have been developed previously. The new technology is also being developed to grow the virus in cell culture, which promises a higher production rate, lower costs, better quality and better surge capacity. Research on A universal influenza vaccine, which aimed at the external domain of the transmembrane viral M2 protein (M2e), being implemented by the University of Ghent by Walter Fiers, Xavier Saelens, and his group and now has successfully passed phase 1 clinical trials.
A number of biologic, vaccine and therapeutic imunobiologic also being studied for treating infections caused by viruses. Biology therapeutic designed to activate an immune response against the virus or antigen. Biologic usually do not target metabolic pathways such as antiviral drugs, but to stimulate immune cells such as lymphocytes, macrophages, and / or antigen presenting cells to provide an immune response against the cytotoxic effects against the virus. Model of influenza, such as influenza mice (murine influenza) is a good model to be used to test the effects of prophylactic and therapeutic biologic. Examples lymphocyte T-Cell Immune Modulator inhibits influenza virus growth in murine models.
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