Can Flu Pandemics Be Stopped or Prevented?
There are four different antiviral drugs (amantadine, rimantadine, oseltamivir, and zanamivir) that are approved by the U.S. Food and Drug Administration (FDA) for the treatment and/or prevention of influenza. All four drugs usually work against influenza A viruses. However, the flu medicines may not always work, because strains of the influenza virus can become resistant to one or more of these medications. For example, the influenza A (H5N1) viruses that were identified in humans in Asia in 2004 and 2005 have been resistant to amantadine and rimantadine. However, researchers are still monitoring avian viruses for resistance to other antiviral medications.
Many scientists believe it is only a matter of time until the next pandemic flu occurs. The severity of the next pandemic cannot be predicted, but modeling studies suggest that the impact of another pandemic flu on the United States could be substantial.
In the absence of any control measures (vaccination or drugs), it has been estimated that in the United States, a "medium–level" pandemic flu could cause:
- 89,000 to 207,000 deaths
- 314,000 to 734,000 hospitalizations
- 18 to 42 million outpatient visits
- 20 to 47 million cases of illness.
Between 15 percent and 35 percent of the U.S. population could be affected, and the economic impact could range between $71.3 and $166.5 billion. Influenza pandemics are different from many of the threats for which public health and healthcare systems are currently planning.
A pandemic flu will last much longer than most public health emergencies, and may include "waves" of influenza activity separated by months of inactivity. In the 20th century pandemics, a second wave of influenza activity occurred 3 to 12 months after the first wave.
If another pandemic flu were to occur:
- The number of healthcare workers and first responders available to work can be expected to be reduced
- Healthcare workers and first responders will be at high risk of illness through exposure in the community and in healthcare settings, and some may have to miss work to care for ill family members
- Resources in many locations could be limited, depending on the severity and spread of the flu.