Influenza, commonly referred to as “the flu” or just “flu” is a highly infectious illness that spreads rapidly through the coughs and sneezes of people who are carrying the virus. Flu symptoms can hit quite suddenly and severely. They usually include fever, chills, headaches and aching muscles. You can often get a cough and sore throat.{{more}}

Influenza is estimated to cause three to five million cases and 250,000 to 500,000 deaths worldwide each year. The most severe influenza pandemic, in 1918, infected up to 50 per cent of the world’s population and caused 20 to 50 million deaths worldwide. The use of antiviral drugs can lessen the severity of disease. Vaccines against seasonal influenza are made yearly to defend against currently circulating strains; however, vaccines that can be produced quickly, affordably, and in mass quantity to respond to a potential influenza pandemic in real-time are not yet available.

Because the flu is caused by a virus and not bacteria, antibiotics won’t treat it. It makes no sense to take antibiotics when you come down with the flu. Anyone can get flu, but it can be more serious for certain people, such as those aged 65 or over, people who have a serious medical condition, especially those who are immunocompromised and pregnant women.

If you are in one of these groups, you are more vulnerable to the effects of flu (even if you’re fit and healthy) and could develop flu complications, which are more serious illnesses such as bronchitis and pneumonia that could result in hospitalization. Flu can also make existing medical conditions worse.

An annual seasonal flu vaccine (either the flu shot or the nasal spray flu vaccine) is the best way to reduce the chances that you will get seasonal flu and spread it to others. When more people get vaccinated against the flu, less flu can spread through that community.

Flu vaccines cause antibodies to develop in the body about two weeks after vaccination. These antibodies provide protection against infection with the viruses that are in the vaccine.

The seasonal flu vaccine protects against the influenza viruses that research indicates will be most common during the upcoming season. Traditional flu vaccines (called “trivalent” vaccines) are made to protect against three flu viruses: an influenza A (H1N1) virus, an influenza A (H3N2) virus, and an influenza B virus. There are also flu vaccines made to protect against four flu viruses (called “quadrivalent” vaccines). These vaccines protect against the same viruses as the trivalent vaccine and an additional B virus.

Dr Rosmond Adams, MD is a medical doctor and a public health specialist with training in bioethics and ethical issues in medicine, the life sciences and research. He is the head of Health Information, Communicable Diseases and Emergency Response at the Caribbean Public Health Agency (CARPHA). (The views expressed here are not written on behalf of CARPHA).

Dr Rosmond Adams is a medical doctor and a public health specialist.

He may be emailed at:adamsrosmond@gmail.com