Connecticut State Department of Public Health

Facts About Pandemic Flu

What is pandemic influenza? How is it different from ordinary flu? How likely is an influenza pandemic? Will it affect us in Connecticut?

What is pandemic flu?

A pandemic occurs when a disease spreads rapidly, affecting most countries and regions of the world. Influenza pandemics have occurred periodically throughout human history – including a major pandemic in 1918, and smaller pandemics in 1957 and 1968. The symptoms of pandemic influenza are similar to those of ordinary flu but are usually more severe.

How does a flu pandemic start?

Flu viruses are constantly changing, producing new strains. Influenza pandemics occur when a virus emerges that is so different from previously strains that few, if any, people have any immunity to it. This allows it to spread widely and rapidly, potentially affecting millions of people worldwide. The new virus may be the result of an animal virus, usually from a bird, mixing with a human virus to produce a new strain.

What is the difference between pandemic flu and ordinary flu?

Ordinary Flu

  • Occurs every year during the winter
  • Affects up to about 10% of the population
  • For most people it is an unpleasant but not life-threatening infection
  • The very young, the very old, and people with certain chronic illnesses are most at risk of serious illness
  • Annual vaccination is available
  • Antiviral drugs are available to treat those at special risk

Pandemic Flu

  • Has occurred three times in the last 90 years
  • Can occur at any time of the year
  • Is a more serious infection for everyone
  • People of every age may be at risk of serious illness
  • A vaccine probably won’t be available when the pandemic starts – when it does become available the aim will be to immunize people as rapidly as possible as vaccine supplies become available
  • Antiviral drugs are likely to be in limited supply and will have to be used to best effect according to how the disease develops

Vaccine against ordinary flu will not protect against pandemic flu. However, getting your annual flu shot is one of several things you can do to keep yourself healthy, and that may help you fight off the pandemic virus.

How likely is a flu pandemic?

Three pandemics have occurred in the last 90 years, in 1918, 1957 and 1968. Scientists predict that another pandemic will happen, although they cannot say exactly when.

How likely is it that pandemic flu will spread to the U.S.?

The World Health Organization, CDC, and the Connecticut Department of Public Health are watching for the first signs of an emerging pandemic.

In 1918, pandemic influenza spread across the country in less than a month. Now, in the era of international air travel, a pandemic will probably spread even faster. As a result:

  • Many people will get sick with the flu
  • There will be a huge demand for health services
  • Many aspects of daily life will be disrupted
  • There will be many deaths

Connecticut is working with many different collaborators and partners to prepare for a possible pandemic.

How likely am I to catch pandemic flu?

You are more likely to catch it than ordinary flu because it spreads rapidly and very few people will have any immunity to it. Everyone will be at risk. Some groups of people may be more at risk than others, but every pandemic is different, so until the virus starts spreading it is very difficult to predict who these groups might be. With ordinary flu the groups of people more likely to become seriously ill include:

  • The very young
  • People over 65 years of age
  • People with existing medical conditions such as lung diseases, diabetes, cancer, kidney, or heart problems
  • People who have immune system problems because of certain medical treatments, or illnesses like HIV/AIDS

The groups most likely to become ill will probably be different during a pandemic.

How will I know if pandemic flu has reached the U.S.?

The World Health Organization has an international system in place for tracking the emergence of a new pandemic. CDC, the U.S. Department of Health and Human Services (DHHS), and the Connecticut Department of Public Health will also be monitoring the situation.

If it looks like a pandemic is going to reach the U.S., the government will issue warnings and work with the media to advise people on the best course of action. If it looks likely that a pandemic will reach Connecticut, health officials will use the media and this website to advise people on what they should do.

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