Influenza+and+Humans

Influenza and Humans Mackenzie Olesen

The influenza virus is part of the [|Orthomyxoviridae] family. Orthomyxoviruses contain strands of RNA inside an envelope that will ultimately be released inside a host cell. There are four types of genera from the RNA, being A, B, C, and Thogotovirus. [9]

The seasonal [|influenza] virus is composed of the A and B strands. Strand A mutates and is what causes most of the struggle in developing an influenza vaccination every year. [9][12][20]

On average up to 20% of the population in the United States contracts the seasonal flu virus every year. This results in up to 49,000 people dying per year due to the influence of the flu. After contraction of the virus, the patient can remain contagious for up to 10 days, in which they can pass on the virus to anyone they get in contact with, especially before symptoms begin to show. [19] In 1918 up to 100 million people died from the flu, with around 67% dying in the fall time alone. [11][23] This is just one example of how devastating a flu epidemic can be. 1 Influenza Virus 1.1 Structure 1.2 Mechanism 1.3 Mutation 2 History of Influenza Treatment 2.1 Contraction 2.2 Symptoms 2.3 Treatment 3 Influenza Treatment Today 3.1 Strain Identification 3.2 Vaccination Growth 3.3 Administration 3.4 Policies 4 Immune System Effect 4.1 Effect on a Weak Immune System 4.2 People Most at Risk 5 Conclusion 6 References ||
 * ** Contents **

__ Structure __ The influenza virus is spherical in shape; a [|lipid membrane] encases RNA strains inside. [4] Inside the lipid membrane is the matrix protein M1, which gives the membrane its form and strength to protect the RNA inside. [15] [|Glycoprotein] spikes are spaced along the outside of the membrane and along the M1 proteins. The glycoprotein subtypes on influenza A are hemagglutinin (HA) and neuraminidase (NA). [5] These glycoproteins allow the virus to attach to the host cell [11] and are what antibodies recognize when attacking the virus (Racaniello 2009). Along the M1 protein matrix are also [|ion channels] (M2). [5]
 * Influenza Virus **

Structure of a Virus

__ Mechanism __ The host cell is bound to the virus through the HA spikes. The HA spike is composed of two parts: the head, where the spike attaches to the host cell, and a stalk. There is then a conformational change that allows the RNA from the virus to move to the host cell, and the M2 ion channel moves hydrogen ions inside to assist replication. The [|RNA] is then incorporated into the host cells genome, fully infecting it. The new DNA containing the virus then continues to replicate. The process is finished when newly replicated RNA strands move back into the virus and the HA detaches from the cell. The viral RNA also contains coding so that additional copies of the virus are also released from the host cell. [3][5]    Viral Replication

__ Mutation __ The [|mutation] that causes the most issues for developing a vaccine occurs in the head of the HA glycoprotein, which makes it harder for the correct antibodies to recognize and attack the virus. Mutations in the virus are caused by a push in the immune system. Through a large exposure of antibodies to the virus, the virus adds [|amino acids] to the head of HA glycoprotein so that the antibodies can no longer recognize it. [3]

__ Contraction __ The influenza virus moves from one infected person to another through [|aerosols], water droplets, which are caused through breathing, coughing, or sneezing and passes on the virus in close proximity. [9][18]
 * History of Influenza Treatment **

__ Symptoms __ The symptoms for Influenza first show up within 1-3 days after the virus is contracted. The symptoms consist of a fever, headache, body aches, fatigue, coughing, and sometimes vomiting or diarrhea. Influenza most commonly will go away within 3-5 days, but under more serious cases it can result in [|pneumonia] or even death. [9]

__ Treatment __ [|Immunization] methods first started being explored hundreds of years ago through empirical methods. Buddhists would ingest small doses of snake venom to acquire immunity towards snakebites. [1] In 1796 a thirteen year-old boy was introduced to the vaccine virus (cowpox) by Edward Jenner and was the first official vaccination case, leading to an immunity towards smallpox. In 1798 the smallpox vaccination was created, by 1979 there were no more cases of smallpox. [1] This led to the influenza vaccination being composed of small concentrations of the virus being injected into a patient so that their bodies build up the correct antibodies to attack and recognize the virus properly during the flu season. [22]

__ Strain Identification __ In order to pick out the [|viral strains] to get addressed for the seasonal flu vaccination, several things need to be evaluated to make the decision. Directors of the World Health Organization look at surveillance, lab studies, and clinical trials pertaining to influenza. All of the results help to develop a vaccination that will be the most effective. [10]
 * Influenza Treatment Today **

__ Vaccination Growth __ After the strain is chosen, the vaccination is grown in chicken eggs. This allows for a cheap and effective way to get a good amount of vaccinations. However,here is a strong underlying issue with this method. When the vaccination is grown in the egg, a protein on the virus mutates to make the virus more compatible with chicken cells. This mutation makes it so that the vaccination isn't effective in humans. This system needs to be revised, possibly by use of mammalian cells, so that the vaccinations are effective in humans. [22]

__ Administration __ Certified health care workers administer the [|influenza vaccination] every year roughly before the flu season begins. The flu shot can be predominantly received at clinics, doctor’s offices, pharmacies, health departments, urgent care clinics, and college health care centers. [10]

__ Policies __ Despite always being the channel for distributing the seasonal flu vaccination, less than half of hospitals require their health care workers to receive the seasonal flu vaccination. [7] If hospitals changed their policies so that vaccinations are required then a total of 30% more workers would receive vaccinations, resulting in 6% less health care workers taking sick leave during the flu season. [6] Furthermore, if 90% of the health care workers received vaccinations that would result in 30,000 less people contracting the flu in California alone. [4] The health care providers are much more exposed to the flu virus, many times going to work sick [6], resulting in many health care workers becoming carriers, and passing the virus onto their patients.

__ Effect on a Weak Immune System __ The benefit of vaccinations was evaluated for patients with [|heart failure]. It was found that when the patients with heart failure received vaccinations, the chance of dying during the flu season was decreased by 50% and decreased by 20% outside of the typical flu season. These finding are arguably significant due to the fact that 6.5 million adults in the United States have heart failure. Currently only about 26-86% of patients with heart failure actually receive the vaccination. This has been traced back to the patients not receiving the proper recommendations to push them towards getting vaccinated. [2]
 * Immune System Effect **

Vaccinations are foregone under the circumstance that it is believed the immune system has developed [|immunity] and is healthy enough to not need the influenza vaccination annually. Studies have found that the immune system has a stronger first line of defense with the vaccination regardless of natural immunity. [16]

__ People Most at Risk __ As patients get older these dangers increase. A study was conducted to evaluate how to best rectify this situation. When a vaccination dose that was four times its original dose was administered the rate for hospital admission for patients in nursing homes dropped from 20.9% to 19.7%. This results in one person prevented from being administered into the hospital for every 83 patients that receive the high dosage vaccination. [18]

It’s important for health care workers to receive the influenza vaccine every year for the sake of the elderly patients that they are treating. Patients that are elderly have weaker immune systems so that they often cannot make the antibodies needed to respond to the vaccinations so that they cannot receive the vaccination, it makes them more susceptible to getting ill during the seasonal sickness period. These elderly patients are mainly exposed to their health care workers, which makes them most susceptible to contracting anything that the workers are carrying. A study found that when vaccinations were mandatory for healthcare workers there was a 10% patient mortality rate compared to the previous 17% mortality rate. [14]

Besides the elderly being highly susceptible to contracting the influenza virus, children under five years are also at a high risk. Their high risk is due to their immune systems still developing so that they don’t respond as well to a foreign virus as well as an adult. [21]

Vaccinations were administered to pregnant mothers to evaluate its effect on infant hospitalizations. The study supported that there is in fact a correlation between vaccinations in pregnant mothers and a decrease in infant hospitalizations. [13]

While many new advances and knowledge are coming out that pertain to influenza vaccinations a main issue still stands out. Despite more effective vaccinations being developed many people still won’t receive the vaccination. This starts at the hospital where many health care workers don’t get vaccinated. [7] Educating the population about the value of receiving vaccinations could rectify this issue. Overall, there is a significantly higher benefit for everyone to receive the influenza vaccination annually rather than foregoing it. Better surveillance of the population is also found to assist in preventing pandemics. [8]
 * Conclusion **

1. A brief history of vaccination. (2017, April 04). Retrieved from http://www.immune.org.nz/vaccines/vaccine-development/brief-history-vaccination
 * References: **

2. American College of Cardiology. (2018, February 28). Getting flu vaccine cuts risk of early death by half in people with heart failure: Analysis of six studies supports routine influenza vaccination for heart failure patients. //ScienceDaily//. Retrieved March 14, 2018 from [|www.sciencedaily.com/releases/2018/02/180228085407.htm]

3. Anderson, C. S., Ortega, S., Chaves, F. A., Clark, A. M., Yang, H., Topham, D. J., & DeDiego, M. L. (2017). Natural and directed antigenic drift of the H1 influenza virus hemagglutinin stalk domain. //Scientific Reports//, //7//(1). []

4. Association for Professionals in Infection Control. (2014, June 4). When hospital workers get vaccines, community flu rates fall, study shows. //ScienceDaily//. Retrieved February 23, 2018 from [|www.sciencedaily.com/releases/2014/06/140604105435.htm]

5. Bouvier, N. M., & Palese, P. (2008). THE BIOLOGY OF INFLUENZA VIRUSES. //Vaccine//, //26//(Suppl 4), D49–D53.

6. Frederick, J., Brown, A. C., Cummings, D. A., Gaydos, C. A., Gibert, C. L., Gorse, G. J., … Simberkoff, M. S. (2018). Protecting Healthcare Personnel in Outpatient Settings: The Influence of Mandatory Versus Nonmandatory Influenza Vaccination Policies on Workplace Absenteeism During Multiple Respiratory Virus Seasons. //Infection Control & Hospital Epidemiology//, 1–10. []

7. Greene, M. T., Fowler, K. E., Krein, S. L., Gaies, E., Ratz, D., Bradley, S. F., & Saint, S. (2016). Influenza Vaccination Requirements for Healthcare Personnel in U.S. Hospitals: Results of a National Survey. //Infection Control & Hospital Epidemiology//, //37//(04), 485–487. []

8. Hswen, Y., Brownstein, J. S., Liu, J., & Hawkins, J. B. (2017). Use of a Digital Health Application for Influenza Surveillance in China. //American Journal of Public Health//, //107//(7), 1130–1136. []

9. Influenza Virus. (2009). //Transfusion Medicine and Hemotherapy//, //36//(1), 32–39. []

10. Influenza (Flu). (2016, May, 04). Retrieved April 08, 2018, from https://www.cdc.gov/flu/about/season/vaccine-selection.htm

11. McDougal, W. (n.d.). Influenza Virus: Structure and Function. Retrieved April 24, 2018, from []

12. Moore, Jesse T, et al. Human Influenza: Viral Mutations and Altered Tropisms. //Human Influenza: Viral Mutations and Altered Tropisms//, vol. 12, no. 2, Mar. 1999, doi:https://search-proquest-com.colorado.idm.oclc.org/docview/204796191?pq-origsite=summon&accounted=14503

13. Nunes, M. C., Cutland, C. L., Jones, S., Downs, S., Weinberg, A., Ortiz, J. R., … Madhi, S. A. (2017). Efficacy of Maternal Influenza Vaccination Against All-Cause Lower Respiratory Tract Infection Hospitalizations in Young Infants: Results From a Randomized Controlled Trial. //Clinical Infectious Diseases//, //65//(7), 1066–1071. []

14. Potter, J., Stott, D. J., Roberts, M. A., Elder, A. G., O’Donnell, B., Knight, P. V., & Carman, W. F. (1997). Influenza Vaccination of Health Care Workers in Long-Term-Care Hospitals Reduces the Mortality of Elderly Patients. //Journal of Infectious Diseases//, //175//(1), 1–6. []

15. Racaniello, V. (2009, April 30). Structure of influenza virus. Retrieved April 24, 2018, from http://www.virology.ws/2009/04/30/structure-of-influenza-virus/

16. Trieu, M.-C., Zhou, F., Lartey, S., Jul-Larsen, Å., Mjaaland, S., Sridhar, S., & Cox, R. J. (2016). Long-term maintenance of the influenza-specific cross-reactive memory CD4+ T-cell responses following repeated annual influenza vaccination. //Journal of Infectious Diseases//, jiw619. []

17. University Hospitals Case Medical Center. (2015, October 10). Study finds significant decrease in hospitalization of older nursing home residents with high dose influenza vaccine. //ScienceDaily//. Retrieved March 14, 2018 from [|www.sciencedaily.com/releases/2015/10/151010225418.htm]

18. University of Maryland. (2018, January 18). Flu may be spread just by breathing: Coughing and sneezing not required for transmission. //ScienceDaily//. Retrieved March 14, 2018 from [|www.sciencedaily.com/releases/2018/01/180118142611.htm]

19. What Are Your Odds of Getting the Flu? (n.d.). Retrieved April 07, 2018, from []

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21. Who is Most Susceptible to the Flu Virus? (2013, January 11). Retrieved from http://www.foxnews.com/health/2013/01/11/who-is-most-susceptible-to-flu-virus.html

22. Wu, N. C., Zost, S. J., Thompson, A. J., Oyen, D., Nycholat, C. M., McBride, R., … Wilson, I. A. (2017). A structural explanation for the low effectiveness of the seasonal influenza H3N2 vaccine. //PLOS Pathogens//, //13//(10), e1006682. []

23. III, A. H. (2018, January 27). The Flu Can Kill Tens of Millions of People. In 98, That’s Exactly What it Did. Retrieved April 07, 2018, from [|https://www.washingtonpost.com/news/retropolis/wp/2018/01/27/the-flu-can-kill-tens-of-million-of-people-in-1918-that’s-exactly-what-it-did/?utm_term=.047a41fc5687]