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Pandemic influenza (flu): Key facts

(Figures in brackets refer to the paragraph in the main text describing that topic in more detail).

1. The disease

  • Pandemic influenza (flu) is a type of influenza that occurs every few decades and which spreads rapidly to affect most countries and regions around the world (1.1).
  • Unlike the 'ordinary' flu that usually occurs every winter in the UK, pandemic flu can occur at any time of year (1.3).
  • Pandemics of influenza have occurred occasionally for centuries - three times in the last hundred years - resulting in many thousands of deaths (1.4).
  • Experts predict another pandemic but cannot say exactly when it will happen. When it does, it may come in two or more waves several months apart and each wave may last two to three months (3.2).
  • Pandemic flu is much more serious than 'ordinary' flu. As much as a quarter of the population may be affected - maybe more (4.2.2).
  • Pandemic flu is likely to cause the same symptoms as ordinary flu but the symptoms may be more severe because nobody will have any immunity or protection against that particular virus (4.2.2).
  • A serious pandemic is also likely to cause many deaths, disrupt the daily life of many people and cause intense pressure on health and other services (4.3).
  • Every pandemic is different, and until the virus starts circulating, it is impossible to predict its full effects (4.3).

2. What is it caused by?

  • Pandemics of flu are due to the emergence of a new flu virus which is markedly different from recently circulating strains and to which few - if any - people have any immunity. This allows it to spread widely, easily and to cause more serious illness (1.2).

3. Who's at risk?

  • Once a pandemic flu starts everybody will be at risk of getting pandemic flu. Certain groups may be at greater risk than others: until the virus starts circulating we will not know for sure who they will be (Table 1.2).

4. Is there a vaccine to protect against pandemic flu?

  • There is no vaccine ready to protect against pandemic flu. The virus that causes pandemic flu will be new and a vaccine to protect against it cannot be made until the virus has been identified. Before a pandemic starts it is difficult, if not impossible, to predict what strain will cause it and even then, predictions may prove wrong, or the predicted virus may have changed enough for a pre-prepared vaccine to be ineffective. 'Ordinary' flu vaccines will not provide protection and having had the 'jab' in the recent past does not protect someone (3.4).
  • Medicines called antivirals can be used to treat pandemic flu but their effectiveness won't be known until the pandemic virus is circulating (3.5).

5. What is the government doing to prepare for a flu pandemic?

  • The government has drawn up a UK-wide Influenza Pandemic Contingency Plan which will be put into action in the event of a pandemic. The Plan includes actions to improve our preparedness now, before another pandemic occurs (5.3).
  • NHS staff will be trained in how to manage a pandemic and cope with the demands that are likely to be placed on them (5.3.2).
  • The government is taking steps to be in the best possible position for a vaccine to be manufactured as rapidly as possible when a pandemic virus is identified (manufacture is still likely to take several months, however, and vaccine is unlikely to be ready at the start of a new pandemic) (3.4.3).
  • The government is building up its stocks of antiviral drugs. They will be used in the most effective way to treat those most at risk of serious illness based on how the disease develops (3.5).
  • If pandemic flu reaches the UK, there will be announcements in the newspapers, and on radio and TV, and advice will be given on the best course of action to take. Simple hygiene measures and reducing social contact could help to slow spread and buy time until a vaccine is ready (5.3.2).

6. What can I do?

  • You can reduce, but not eliminate, the risk of getting or spreading influenza during a pandemic, as at any time, by:
    - maintaining good basic hygiene, for example washing your hands to prevent spreading the virus from your hands to your face
    - covering your nose and mouth when coughing or sneezing
    - avoiding crowds whenever possible (3.6).
  • If you do catch flu:
    - stay at home and rest
    - take medicines to relieve the symptoms (following the instructions with the medicines)
    - drink plenty of fluids.
    This is both for your own health and to avoid spreading the illness to others.

More information will be given at the time of a pandemic through leaflets, websites and the media. Such information will tell you how you can protect yourself and your family and what to do if you think you are infected. Some people will be recommended treatment - further information will be given at the time.

For more information:

  • visit www.nhsdirect.nhs.uk
  • go to NHS Direct Interactive on digital satellite TV by pressing the interactive button on the remote control
  • call NHS Direct on 0845 4647 (calls charged at local rates)
  • visit www.dh.gov.uk/pandemicflu and www.immunisation.nhs.uk
  • pick up the leaflet Pandemic flu from your doctor's surgery or clinic.

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