Imagine this: A dangerous virus, with origins in the Southern Hemisphere, is about to begin infecting millions of Americans and could end up killing tens of thousands. At the same time, federal, state and local health officials are marshalling resources to defend against an outbreak that has the potential to overwhelm the countrys healthcare system.
Though it may seem eerily similar to the plot of the feature film 'Contagion,' this scenario is not a work of fiction. The virus in question is seasonal influenza and, since last winter, public health officials have studied outbreaks in Australia and other areas south of the equator to develop this years flu vaccine.
In 'Contagion,' scientists scramble to diagnose and stop a new strain of flu virus that suddenly achieves pandemic status, killing countless people around the world. In real life, officials from the World Health Organization (WHO) and the Centers for Disease Control and Prevention (CDC) have carefully tracked the seasonal flu virus to prepare a vaccine that should protect most people in this part of the world. Still, a vaccine works best only if enough people take advantage of it. Though infrequent, pandemics do occur, the most recent being the worldwide swine flu pandemic of 2009.
"Contagion will probably scare some people but thats not necessarily a bad thing if it motivates them to get vaccinated," says Dr. George DiFerdinando, adjunct professor of epidemiology at the UMDNJ-School of Public Health and the director of the New Jersey Center for Public Health Preparedness, which is based at the school. "The fact is, seasonal flu should worry people. In an average year, the flu can kill more than 30,000 Americans and cause 200,000 hospitalizations. So, if Contagion convinces even one more person to get vaccinated, thats a good thing."
Despite months of preparation by public health officials, seasonal flu remains a moving target that never takes a year off, DiFerdinando says. "The influenza virus isnt like small pox or polio viruses that have remained the same over the years. The flu virus constantly mutates, even while its in your body. The virus that makes you sick could actually be different from the one you pass on to another person."
The ability of the virus to mutate helps explain why flu seasons can be unpredictable and why some people will develop the illness even after they have been vaccinated.
"The seasonal flu vaccine can never be 100 percent effective, but its still very good," DiFerdinando says. "Even if you get the flu after being vaccinated, you are likely to get a much less severe case. Keep in mind, too, that there are two reasons to get vaccinated. You keep yourself free of the illness and you avoid spreading it to others such as young children, the elderly, or those with chronic diseases who are most at risk from serious complications from the flu. You help others while helping yourself."
This years vaccine will again contain one strain of influenza B virus and two strains of influenza A (including the H1N1 virus that caused the worldwide pandemic two years ago). The CDC recommends the flu vaccine for virtually all individuals who are older than six months. More information about seasonal influenza is available on the Flu Prevention Information page on the CDC website.