Influenza viruses are capable of wreaking havoc on society and on individuals. The impact on public health has been tremendous over the course of history, and previous pandemics have resulted in the deaths of thousands. However, influenza may mean only a temporary setback to an individual.
Public Health
A pandemic is a worldwide disease outbreak. Flu.gov calls the 1918 influenza outbreak "The Great Pandemic." Twenty to 40 percent of the world's population became ill, and there were a tremendous number of deaths. More recent is the H1N1 influenza pandemic of 2009. While this pandemic has ended, the virus still exists and is circulating in the world's population. The cost to society is employees out of the workforce, an increased burden on the health care system, school absenteeism and worldwide fear. Seasonal influenza differs from a pandemic in that it occurs yearly in the fall. Fewer people are affected and, to some extent, the virus type and spread is predictable. A pandemic may result when a new subtype of influenza virus infects humans and easily spreads, causing serious illness, according to Flu.gov.
Individual Symptoms
Infection with an influenza virus tends to produce a constellation of symptoms that is fairly consistent in spite of the many subtypes of the virus. Fever and/or chills, cough and muscle aches are very common. Sore throat, fatigue, headache and runny nose may be similar to symptoms experienced with the common cold, but are usually more severe. Vomiting and diarrhea may be present, especially with subtype H1N1, notes Flu.gov. Fortunately, tests are available to diagnose influenza, and there are specific antiviral medications to combat the infection. Possible complications of influenza include pneumonia, ear and sinus infections, and dehydration; complications tend to be worse in people with chronic medical conditions such as asthma or diabetes, according to Centers for Disease Control and Prevention.
Vaccine
Developing an effective vaccine against influenza is challenging due to the large number of virus subtypes. To make the task even more daunting, the viruses change their genetic material frequently, rendering previous immunity ineffective. Three virus subtypes are chosen for the seasonal flu vaccine based on predictions of activity for the upcoming autumn, according to the Centers for Disease Control. The vaccine takes about two weeks to become effective. Due to changing circumstances and viral variability, the CDC recommends an annual vaccination.
