Another reason is because strains can change over time, making the initial vaccine much less effective.
"Flu season is here until possibly as late as May, and we anticipate an active flu season this year", said Sherry Gregory, RN, Infectious Disease Supervisor of the North Georgia Health District, based in Dalton.
Each year, millions of Americans receive a flu shot in the hopes of reducing their risk of contracting seasonal influenza or at least in the hopes of lessening the symptoms if they do contract the disease.
Medical experts say however imperfect the flu shots are, current influenza vaccines remain a valuable public health tool, and it is always better to get vaccinated.
The flu shot you received this year may not protect you from contracting the potentially deadly disease, scientists are warning.
The CDC recently issuing their report saying Louisiana in particular is suffering from a "widespread" threat.
The flu season is upon us and it's expected to be one of the worst.
"In a good year, the flu vaccine can be 70 percent effective". Parents also need to know when to keep kids home. Preventive actions such as simply washing hands and covering the nose and mouth when sneezing or coughing can guard against the flu.
The vaccination can help lessen the severity of the illness, which is important for children and people over the age of 50 with underlying health conditions, as these populations are more likely to suffer from flu complications like pneumonia.