A study published in the December 11 issue of the "Proceedings of the National Academy of Sciences" reported that seasonal outbreaks of influenza can be forecast much like the weather. Future precipitation, temperature, and other weather conditions were used to predict the peak of the flu season in New York as much as seven weeks in advance. But prediction isn't the same as prevention, and scientists are continually working to improve that part of the equation.
Efforts to create a vaccine to prevent influenza began in earnest after doctors were helpless to prevent widespread mortality during the devastating Spanish Flu pandemic of 1918—1919. An estimated 50 to 100 million people died and 500 million were sickened during that outbreak.
World War I had not yet ended when the virus struck. Because it was feared the enemy might use the virus for tactical advantage, news of its spread was censored. Spain, which had remained neutral during the war, did report news of the outbreak, and so the pandemic became known as "Spanish Flu," even though it was believed to have originated in the U.S. The disease was so severe that more soldiers may have died from influenza than from warfare. Some victims were dead within only hours, their lungs filling with fluid so rapidly that they suffocated.
In 1931, Ernest William Goodpasture and fellow scientists at Vanderbilt University discovered they could grow an influenza virus in fertilized hens' eggs, but it wasn't until the 1940s that a working vaccine was developed and mass produced. It was initially used for soldiers during World War II.
Perhaps one of the most successful influenza containment efforts occurred during the Swine Flu scare of 1976. Although a widespread vaccination program had begun in the U.S., the new strain of virus was successfully contained on the army base where it originated, Fort Dix in New Jersey, where 13 people were hospitalized and one died. The vaccination program was cancelled after less than three months, at which point 24% of the population had been immunized.
The program was halted in part because it was no longer necessary, but also in part because there were around 400 hospitalizations and 25 deaths from Guillain-Barré syndrome, a disease affecting the nervous system that is triggered by an immune response to foreign antigens — like those found in vaccinations.
The 1976 virus was a strain of H1N1, which had caused the Spanish Flu pandemic, so there was good reason to take every precaution to prevent its spread. However, the incidents of Guillain-Barré were disconcerting, and became a public relations nightmare at the time. To help allay the public's concerns, President Gerald Ford very publicly received the flu shot to demonstrate how safe he believed it to be.
After 1976, there didn't appear to be the same risk of contracting Guillain-Barré in subsequent influenza vaccines. Because the exact correlation is still unknown, scientists continue to look for possible causes of Guillain-Barré in relation to vaccines, and those who receive the vaccine are informed of the potential, albeit unlikely, risk.
In the ongoing quest to improve vaccination production, in November of 2012 the U.S. Food and Drug Administration approved the first seasonal influenza vaccine to be developed using cultured animal cells rather than fertilized chicken eggs. Although cell culture technology has been used for years to produce other vaccines, this is the first time it has been approved for a flu vaccine. Doing so decreases the time it takes to produce the vaccine, which could be especially helpful for the next pandemic. It also makes the vaccine available to those who otherwise can't be vaccinated due to an allergy to eggs.
Currently the Centers for Disease Control (CDC) reports that the flu is progressing early this year and incidents are on the rise. The CDC's Outpatient Illness Surveillance graphic demonstrates not only the timing (early by about three weeks) but also the severity of the disease this season (moderately severe). The season hasn't yet peaked, so it remains to be seen just how severe it will prove to be.