Immunisation The Best Defence Against Influenza
27 May 2005
Immunisation the best form of defence against influenza
The recent spread of influenza-like illness in Auckland has prompted a reminder from influenza experts that annual influenza immunisation is the best form of defence against the disease.
National Influenza Strategy Group (NISG) spokesman and virologist Dr Lance Jennings said he strongly urged people to get their annual influenza immunisation, particularly those who are most vulnerable and at risk. For these people, influenza can be a serious disease.
The subsidised influenza vaccination campaign for high-risk New Zealanders -- people aged 65 and over and those with long-term health conditions such as heart disease, stroke and diabetes, runs until the end of July.
``There's still time for people who haven't had their vaccination to go and get one, and I would strongly encourage this,'' Dr Jennings said.
``It's free for those in the high-risk groups, and they may well include the parents and grandparents of some of the children who have become sick in Auckland this week, so they may run the risk of being exposed. The only way to protect against influenza is by immunisation, including vaccinating children.??
Dr Jennings said it was also important to remind people that being fit, active and healthy does not protect against influenza ? it's highly contagious and anyone can catch it.
Influenza activity in New Zealand peaked last year at the end of September, a month later than the peak in 2003 and 2002.
Influenza activity information for the week ending May 20 2005 is available on the ESR website.
Background People with long-term health conditions have the greatest risk of complications from influenza and that is why influenza vaccination is provided free to these groups. This includes those 65 years and over, and those adults and children with certain chronic conditions including:
· heart disease
· ongoing respiratory (chest) diseases like chronic bronchitis or asthma (but only those requiring regular preventative medication)
· ongoing renal (kidney) disease
· most cancers
· other conditions affecting the immune system such as HIV/AIDS, rheumatoid arthritis and organ transplants.
Overseas studies have shown that influenza vaccination cuts hospitalisations and deaths in the 65 and over age group during the influenza season.
Vaccination is the best protection against influenza. For everyone in the 'at risk' groups, early vaccination is recommended even if they are feeling fit and healthy.
Anyone wanting more information about influenza can contact their doctor or practice nurse or telephone 0800 - IMMUNE (0800 466863)
Questions and Answers
What is influenza?
Influenza is a serious illness that in New Zealand usually causes epidemics every year during the winter months. The illness comes on suddenly with a fever, sore throat, dry cough, aches and pains and headaches. People feel very unwell and the elderly and chronically ill can develop pneumonia and other problems. They may need hospital care.
Why do people need to vaccinate against influenza?
Influenza immunisation is the best protection against influenza. Influenza infection in people with ongoing medical conditions, even if their condition is well controlled, may lead to more serious illness and death.
Influenza can cause pneumonia and can act as a trigger that makes existing medical conditions worse. In older people and those with ongoing medical conditions such as heart disease, other respiratory problems and diabetes this can lead to hospitalisation and even death.
Where can eligible people get a free vaccination?
Free vaccinations are available from your local General Practitioner even though a practice nurse may be the one who actually administers the injection to you. The vaccine is injected into your upper arm.
How many vaccinations were provided last year?
There were about 704,000 vaccine doses distributed during the 2004 influenza season, a 3.2 percent increase on the number distributed in 2003.
How can I tell the difference between a cold and influenza?
Influenza makes people feel miserable and is much more serious that a common cold. Influenza will leave you ill for up to 10 days. Most people suffer from a high fever and may require bed rest. Some may also have shivering attacks, muscular pains, headaches, a dry cough, possible vomiting and complications like pneumonia can follow. A vaccine is available to protect against influenza.
A cold however has much less severe symptoms and they generally last only 2-4 days. High fever is less common and shivering attacks and severe headaches are rare. Muscular pains and vomiting are infrequent and the cough will be less severe. There is no vaccine available.
How safe is the vaccine?
The immunisation will not give you influenza because the vaccine contains disrupted virus. Most people have no reaction to the injection. Occasionally the place where the injection was given is red or sore. Some people may feel unwell for a day or two. These are normal responses to the immunisation.
Does the vaccine actually work?
Yes. For those at high risk, influenza vaccination reduces hospitalisation by 50 percent and mortality by 70 percent. In general the vaccine is 70-90 percent effective in preventing influenza in healthy adults.
Will I get influenza from the vaccination?
No. Influenza vaccine cannot give you the 'flu as it contains fragments of disrupted virus.
What is the Ministry of Health and National Influenza Strategy Group (NISG) doing to encourage people to be vaccinated?
The main role for NISG and the Ministry of Health is to increase public awareness of influenza and its seriousness. NISG has developed a series of user-friendly resources for the public, some of which address myths about the vaccine. An example is the misconception that taking the vaccine will give the person influenza. These resources are available when you get vaccinated.
NISG has also given health providers resources to help them promote vaccination to all at-risk groups, and established links with relevant organisations to ensure that they are given information and resources to pass on to their members.
Summary of 2004 influenza statistics
During the 2004 influenza season, 3277 consultations for influenza-like illness were reported from a national sentinel network of 86 general practices. It is estimated that influenza-like illness affected more than 35,000 New Zealanders during the season, compared with more than 46,000 people in 2003.
How are the statistics collected?
There are two parts to the influenza surveillance systems in New Zealand - sentinel general practice (GP) surveillance and laboratory-based (mainly hospital) virological surveillance.
General Practice Surveillance
The sentinel GP surveillance system started in 1991 as part of the WHO Global programme for influenza surveillance. It is operated nationally by ESR and locally by influenza surveillance co-ordinators in the public health services.
In 2004, national influenza GP surveillance was carried out from May to October. Local surveillance co-ordinators recruited General Practices within their region to participate on a voluntary basis. GPs recorded the number of consultations for influenza-like illness each week and the age group of each of these suspected cases.
Each practice was also asked to collect throat or nose swabs from patients seen with an influenza like illness each week. The swabs were sent to a regional virus diagnostic laboratory and/or ESR for strain identification.
Laboratory-based surveillance (year round)
In addition to positive identification of the influenza virus from GP surveillance, year round virological surveillance of influenza (and other viruses) is carried out by the four regional virus diagnostic laboratories at Auckland, Waikato, Christchurch and Dunedin hospitals, and by ESR. ESR acts as New Zealand's designated WHO National Influenza Centre.
Each week the regional virus diagnostic laboratories report all viral identifications including influenza largely from hospital in-patients and outpatients, to ESR, where the data is collated and reported nationally.