Flu Vaccine Vanquished Virus for Millions

Flu vaccine may have prevented millions of illnesses and thousands of hospitalizations in US last year

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) The flu vaccine may have kept millions of people in the United States flu-free last year.

In a new study, researchers from the Centers for Disease Control and Prevention (CDC) estimated that, last year, flu vaccines prevented millions of illnesses and thousands of hospitalizations in the US.

According to the authors of this new study, which was led by Carrie Reed, DSc, of the CDC's National Center for Immunization and Respiratory Diseases, a yearly flu vaccine is recommended for everyone 6 months old and older.

Although flu season is already underway, a flu shot may still be useful, Dr. Reed and team noted. These researchers noted that, while particulars of the 2014 to 2015 flu season cannot be predicted exactly, past flu seasons have shown that heavy flu virus circulation can occur as late as March.

"Therefore, vaccination should continue to be offered through the peak periods of influenza virus circulation and as long as influenza viruses are reported to be circulating for the current season," Dr. Reed and team wrote.

The flu is a viral respiratory illness. Symptoms include fever, aches, cough, sore throat, nausea and vomiting. Flu season can begin as early as October and usually peaks in December or February.

Dr. Reed and team drew from a number of different sources for data on the 2013 to 2014 flu season, such as the National Immunization Survey and the US Influenza Vaccine Effectiveness Network.

After looking at this data, Dr. Reed and team estimated that vaccinations prevented 7.2 million flu cases last year. This included an estimated 3.1 million cases that might have required medical attention.

These researchers also estimated that flu vaccines prevented 90,000 hospitalizations last year.

The flu vaccine is a shot that contains a dead flu virus. It prevents the flu by causing the body to have an immune response to the deadened virus, which cannot sicken patients. Patients who have received the vaccine are much less likely to become infected with a live version of the virus.

Dr. Reed and colleagues noted that, despite the number of illnesses the flu vaccine likely prevented, less than half of people received a vaccine as recommended.

If vaccination levels had reached national goals of 70 percent coverage, 5.9 million more illnesses and 42,000 hospitalizations might have been avoided, Dr. Reed and colleagues said.

Some of the data used to make these estimations involved patient-reported data on flu vaccinations, the study authors noted. Further research is needed to confirm these findings, Dr. Reed and team said.

This study was published Dec. 12 in the CDC's Morbidity and Mortality Weekly Report.

The authors disclosed no funding sources or conflicts of interest.

Review Date: 
December 13, 2014
Last Updated:
December 17, 2014