Since 1819, we have records of its annual appearance. In that year, flu reached what we call pandemic status, where it infects huge numbers of people. Influenza that season sickened 500 million people, nearly a third of the world’s population at the time, and killed between 20 and 30 million. Luckily, flu season has only reached pandemic proportions a few times. Generally, it qualifies as a seasonal epidemic where many will get sick around the same time but not such a significant portion of the population as in 1819.
But what exactly is influenza? Many people confuse gastroenteritis or “stomach flu” with influenza. True, influenza is a respiratory illness that gives systemic symptoms, affecting the entire body at times. Influenza is a virus that is spread by infected droplets. These droplets can infect people via air as they can be aerosolized through coughing and sneezing and torpedo as far as 3 to 4 feet. Influenza can also be contracted through droplet particles on hands of the ill person that can latch onto others. The virus then lands in the respiratory tree and causes infection.
Symptoms begin abruptly, and are usually full blown within a few days of exposure, and include fever, sore throat, severe headache and overall body aches. Most influenza cases last five to seven days and generally, recover spontaneously. However, there can be life-threatening consequences if the infection spreads further into the respiratory tree causing pneumonia or into the bloodstream causing sepsis. Even during average flu seasons, deaths occur, likely thousands annually.
While anyone can get the flu virus and be terribly ill, complications such as pneumonia are more likely to occur in several vulnerable populations. Those at the extremes of age, such as people over 65 and under 6 months, are most likely to experience hospitalization and life-threatening complications from the flu. In addition, pregnant women and those with chronic health conditions such as heart disease, asthma and immunodeficiencies are also at high risk for complications and hospitalizations from influenza.
No one, however, is totally free of the chances of serious influenza disease; middle-age, previously healthy males accounted for multiple hospitalizations and severe illnesses nationwide the last few seasons.
It has long been stated that the best offense is a great defense and influenza is no exception. The best treatment for flu is to prevent it, and our best preventive tactic is to get vaccinated. Every year, the influenza virus changes or drifts slightly, making it different from the previous year. Scientists study the virus over time and as it moves around the world to predict the likely strains that will appear in the next season. Generally the vaccine includes three to four flu strains and covers the likely types of influenza A and B expected in the upcoming season. How well those predictions measure up will determine how effective the influenza vaccine is in preventing disease any given year. Not perfect, but is it good enough?
The resounding answer is yes. There are several advantages to vaccination even though it may not be a perfect match. If the vaccine does not totally prevent the disease, it can lessen its effects, called attenuation. This will result in less serious disease, fewer hospitalizations and less death even if the virus is contracted. The vaccine will possibly still decrease infectivity, which is critical to controlling spread. It only takes about two weeks from vaccination until immunity is in place, making vaccination rapidly effective.
And, the disadvantages of vaccination are truly minimal. Due to the constantly changing nature of the virus, a flu shot is needed at the beginning of each season, since long-term immunity is not possible. In any flu shot, there is no live virus, meaning you cannot get the flu from the vaccination. While there may be some side effects, such as soreness or redness at the injection site, slight muscle aches or low-grade fever, they are mild and short lived. One vaccine type, the nasal spray known as “live attenuated influenza vaccine,” does have a very small amount of diluted virus in it and is given mainly to children without cases of severe flu being attributed to it in this population. Determining which vaccine type is best should be made on a case-by-case basis with a care provider.
It is also critical we protect those not aided by the vaccine. This would include the elderly, who, despite needing to get vaccinated, might not respond with strong immunity, or babies less under 6 months who cannot receive the vaccine. In these populations, along with anyone whose immune system does not work well, we need to mitigate their risk by ensuring those around them do not bring the flu into their environment. This phenomenon, known as cocooning, can protect those most likely to experience severe complications of influenza disease, including death.
In addition to vaccination, there are a few tricks to keep in mind once flu season hits.
- Wash your hands. It will prevent droplet spread from person to person.
- Cover your cough and try to avoid those who are ill, at least by staying more than 3 to 4 feet away, to decrease transmission.
- Stay home from work or school when ill to help protect those around us. This is critical, since we don’t know where these germs could spread next – to an elderly grandparent, baby or even a person on chemotherapy who could have devastating consequences from flu.
- See a doctor if you’re extremely ill, and potentially be treated with an antiviral medication that fights flu. These medications are usually most effective when given early in disease and can decrease the symptoms, duration and infectivity of the virus.
With infectious diseases, we should all be 200 percent accountable – for our own health and for that of the vulnerable populations in our communities. Individuals can fulfill this obligation by getting vaccinated for influenza every year and by encouraging their health care systems to achieve a vaccination rate among their employees of above 90 percent, so that our most susceptible, those fighting disease in our hospitals, are protected from complications of influenza. Do it for yourself, your family and your neighbor. Let’s not repeat pandemics of the past.