We all know there is a flu season every year. You wonder whether or not those flu shots are still effective because the virus mutates. The influenza virus has two main surface proteins called "H" and "N" antigens that allow the virus to infect. Flu vaccines effectively trigger antibodies to develop in the body to provide protection against infection from the flu virus. The antibodies produced will prevent subsequent infection if we are exposed to the same flu virus. However, as the flu travels around the world following the flu season, it mutates. If the RNA that codes for either the "H" or "N" antigen mutates, then the protein will be slightly different and those antibodies will no longer bind to provide an effective protection. Fortunately, the likelihood of having both antigens mutate in a given flu season is very small. Chances are that only one of them will change that when we are exposed to this mutated virus the next flu season some of our antibodies bind and some will not. Centers for Disease Control and Prevention (CDC) monitors how the flu virus has mutated every year and makes a new vaccine based on these new strain. So, a new flu vaccine comes out every year. Therefore, an annual seasonal flu vaccine is the best way to reduce your chances of getting the flu and spreading it around. Each year, the flu vaccine contains several different strains of virus that researchers predict to mostly show up that year. If the prediction is correct, the vaccine is 70% to 90% effective in preventing the flu in healthy people under 65 years of age. CDC recommends an annual flu shot
for everyone who is 6 months and older, has not had a previous allergic reaction to a flu shot, or has an allergy to eggs. The flu shot is highly recommended for certain high-risk individuals. These are people with immune-compromised conditions (HIV, cancer, nursing home, ICU patients...), over the age of 65 years, and having chronic medical conditions as well as pregnant women and young children. If you have concerns, it is good idea to consult with a primary care doctor
for more information.