Influenza (the flu) : Flu Shots, Concern for People?

by Health Canada

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The Health Effects of Flu Shots

The benefits of flu shots far outweigh the risks. The flu vaccine cannot cause influenza because it does not contain any live virus. The most common side effect is soreness at the site of injection, which may last a couple of days. You might also notice fever, fatigue and muscle aches within six to 12 hours after your shot, and these effects may last a day or two. Some people develop a condition called "oculo-respiratory syndrome" after a flu shot. The symptoms include red eyes and respiratory effects such as cough, wheezing, chest tightness, difficulty breathing, or sore throat. In most cases, the symptoms are mild and disappear within 48 hours.

Severe allergic reactions to flu shots are rare. A rare but possible side effect of influenza vaccination is Guillain-Barré syndrome (GBS). This is an autoimmune disease that attacks the nervous system and results in weakness and abnormal sensations. But, most patients recover fully. Your chance of developing GBS as a result of a flu shot is one in a million.

The primary reason to get a flu shot is to protect yourself from health effects related to flu. However, by getting a flu shot, you will also help protect other Canadians and reduce the burden on the health care system.

What is avian influenza or "bird flu"?

Birds and other animals, including pigs, also contract and transmit influenza. Wild birds, in particular, are natural carriers of influenza A viruses. They have carried animal influenza viruses, with no apparent harm, for centuries. Migratory waterfowl (ducks, geese) are known to carry viruses of the H5 and H7 strains or subtypes. These viruses are usually in the low pathogenic form - in other words, they aren't as deadly to birds as highly pathogenic strains.

Currently, avian influenza H5N1 is circulating in South East Asian and parts of Europe, infecting many poultry populations and some humans. This strain is highly pathogenic, or highly deadly to birds, and has infected a limited number of people. There is no evidence this virus is transmitted from person to person.

Why is bird flu a concern for people?

People are exposed to different strains of influenza many times during their lives. Even though the virus changes, their previous bouts of influenza may offer some protection against similar strains of the virus. However, three to four times each century, for unknown reasons, a radical change takes place in the influenza A virus causing a new strain to emerge.

One way this radical change can happen is that a person sick with a human influenza virus also becomes infected with the avian influenza virus and the two viruses re-assort or "mix." This means that the avian influenza virus acquires some of the human influenza genes, potentially creating a new subtype of the influenza A virus that people would have no immunity against. If the virus was easily passed to and among people, this would create the conditions for an influenza pandemic.

There is no pandemic influenza at this time anywhere in the world. However, there were three influenza pandemics in the last century and scientists recognize that another is inevitable. That is why governments are planning to prepare to respond to a possible influenza pandemic.

Government of Canada's Role

In Canada, we have a plan for responding to an influenza pandemic. Canada began developing its plan in 1988, long before the threat of the avian H5N1 virus strain was identified as a possible candidate to mix and result in a global pandemic. The Canadian Pandemic Influenza Plan was released in February 2004 and outlines actions to be taken by the various levels of government so that a coordinated response that protects the health of Canadians is implemented in the event of a pandemic. Specifically, it outlines measures to curb infectious disease outbreaks, such as vaccine and antiviral strategies, surveillance, communication and emergency response.

Health Canada, the Public Health Agency of Canada and the Canadian Food Inspection Agency are working collaboratively in consultation with our international partners such as the World Health Organization and the European Centre for Disease Prevention and Control, to monitor the safety of poultry products as it relates to avian flu.

The Public Health Agency of Canada and Health Canada co-ordinate national activities on the prevention and control of flu, including preparations for a worldwide epidemic (or pandemic) of influenza. In addition, the Public Health Agency of Canada conducts surveillance, along with provincial and territorial health ministries and other partners, to assess influenza activity and its spread across Canada in real time. Health Canada and the Public Health Agency of Canada also regulate the safety of vaccines in Canada and help co-ordinate the procurement of flu vaccines for the provinces and territories. These activities ensure that supplies of safe and effective vaccines are available when Canadians need them.

About the Author

www.hc-sc.gc.ca
Health Canada is the Federal department responsible for helping Canadians maintain and improve their health, while respecting individual choices and circumstances.