What can be done to prevent the infection?

An injection of flu vaccine every year can provide protection for people who want to avoid the flu. The flu vaccine is produced roughly 9 to 12 months ahead of the flu season. The formula used is based on what experts believe will be the most common strains of flu virus in the coming season. The vaccine has a 60% to 70% success rate in preventing the different types of influenza viruses each year.

The vaccine is recommended for people considered to be at high risk. These include:

A recent study showed that the flu vaccine may also be effective in preventing second heart attacks in people who have already had a heart attack. In the study, people who received the flu vaccine had a 67% lower incidence of a second heart attack than the people who were not vaccinated that year.

Elderly individuals who are vaccinated against the flu have a significantly lower incidence of hospitalization for respiratory disease, congestive heart failure, and death from any cause.

About 25% of adults who receive the flu vaccine report mild soreness at the site of the injection. Young children may develop fever after a flu vaccine. There is also a slight risk of an allergic reaction to the vaccine. A nasal vaccine for the flu is being tested and may soon be available.

What are the long-term effects of the infection?

While most people recover from the flu without problems, others can develop complications such as:

Influenza and its complications can cause serious disease or even death.

What are the risks to others?

The influenza virus is highly contagious. It is transmitted through respiratory secretions. Sneezing and coughing can spread these droplets. The virus can also be passed on when an individual with the flu touches his or her nose and then handles an object that another person later touches. The second person can then pick up the virus from the object and transfer it into his or her own respiratory tract by touching the face.