Seasonal Influenza

Influenza Vaccine FAQs

About Influenza Vaccination

Children, Pregnancy, and the Immunocompromised Patient

The Importance of Vaccination for Healthcare Providers

References


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 from your general practitioner either before or when you go to be immunised.

NISG has also developed resources to help health providers promote influenza immunisation to all at-risk groups, and has established links with relevant organisations to ensure that they have information and resources to pass on to their members.

Why do people need to vaccinate?

Influenza immunisation is the best protection against influenza. Influenza infection in people with ongoing medical conditions, even if 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, influenza can lead to hospitalisation and even death.


Who is eligible for free influenza immunisation?

Those people with chronic health conditions are more at risk of complications from influenza and that is why the vaccination is provided free to these groups. The following table lists those people who are eligible to receive free influenza vaccine each year:

A – all people 65 years of age and over

B – people under 65 years of age, including children with: cardiovascular disease (ischaemic heart disease, congestive heart failure, rheumatic heart disease, congenital heart disease, cerebrovascular disease, stroke) chronic respiratory disease (asthma if on regular preventive therapy; other chronic respiratory disease with impaired lung function eg chronic bronchitis) diabetes chronic renal (kidney) disease any cancer, excluding basal and squamous skin cancers if not invasive other conditions (autoimmune disease, rheumatoid arthritis, immune suppression, human immunodeficiency virus (HIV), organ transplant recipients, neuromuscular and central nervous system diseases, haemaglobinopathies, children on long term aspirin).

Where can eligible people get a free vaccination?

Free vaccinations are available from your local General Practitioner, the practice nurse is likely to administer the injection to you. The vaccine is injected into your upper arm.


The vaccination is free, but what about the doctor’s visit?

If you are in one of the groups at greatest risk then visit your doctor’s practice for a vaccination before the end of June. The vaccine and administration is free. Note that if you see your GP at the same time for any other reason the GP may charge for this service.

What is happening with the influenza vaccination programme this year?

The funded influenza immunisation programme for eligible individuals began on schedule in March 2006 and will continue until 30 June 2006.


How does a fit and healthy New Zealander who is under 65 receive an influenza vaccination if they choose to?

You can choose to visit your general practitioner to received the influenza vaccine – there will be cost for the vaccine and administration. Alternatively, your workplace may also pay for you to be vaccinated either at work or at your GP’s. The vaccine will be available until at least 30 June 2006.

Will the Ministry of Health monitor flu statistics and trends during winter?

Yes. The influenza surveillance system runs every year. See the ESR website for more details.


Why do people need to vaccinate?

Influenza immunisation is the best protection against influenza. Influenza infection in people with ongoing medical conditions, even if well controlled, may lead to more serious illness.

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.


What influenza vaccines are available this year in New Zealand?

Two influenza vaccines are available this year in New Zealand:

• Fluvax® from Commonwealth Serum Laboratories (CSL) Australia
• Vaxigrip® from Sanofi Pasteur SA France

For more information about these influenza vaccines, see the Medsafe website www.medsafe.govt.nz


Will the Ministry of Health monitor flu statistics and trends during winter?

Yes. If data indicates that the influenza season is occurring earlier than usual -- the peak is normally around the middle of July -- the Ministry will reconsider its programme plan.


Why do people need to vaccinate?

Influenza immunisation is the best protection against influenza. Influenza infection in people with ongoing medical conditions, even if well controlled, may lead to more serious illness.

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.

What happened in the 2005 influenza season?

During the 2005 influenza season, 3929 consultations for influenza-like illness (ILI) were reported from a national sentinel network of 87 general practices. It is estimated that ILI resulting in a visit to a general practitioner affected over 47 108 New Zealanders (1.3% of the total population) during the season, compared with an estimated 35 186 in 2004.

The national level of ILI was relatively high compared with the 1997–2004 period. The highest rates were reported from the Eastern Bay of Plenty and Otago Health Districts. In 2005, 86.9% of influenza isolates were influenza B, and 13.1% were influenza A. Among all typed and subtyped isolates, influenza B/Hong Kong/330/2001 – like viruses were predominant at 71.0%.

The full 2005 report is available at:
http://www.surv.esr.cri.nz/virology/influenza_annual_report.php

Why was PHARMAC given the responsibility of sourcing the supply of influenza vaccine?

PHARMAC took over the responsibility for sourcing the influenza vaccine this year because it is a specialist agency set up to purchase medicines.

Why are annual recommendations for influenza vaccine composition necessary and immunisation needed every year?

Circulating influenza viruses in humans are subject to antigenic changes that require the vaccine formulation to be updated each flu season. This is to ensure the closest possible match between the influenza vaccine strains and the influenza virus strains likely to be circulating.Therefore people need to get vaccinated each year regardless of whether they’ve been vaccinated the year before.

How is it decided which strains should be included in the vaccine each year?

The World Health Organization (WHO) makes recommendations about which strains should be included in influenza vaccines each influenza season. There are two seasons each year, the Northern Hemisphere season and the Southern Hemisphere season.

Information on circulating strains and epidemiological trends is gathered by the WHO Global Influenza Surveillance Network administered by WHO since 1948, the year of WHO’s inception. The Global Influenza Surveillance Network currently consists of 112 national influenza centres in 83 countries and four WHO Collaborating Centres for Reference and Research on Influenza (WHO CC) located in Atlanta, United States; London, United Kingdom; Melbourne, Australia; and Tokyo, Japan.

The National Influenza Centres test samples from patients with influenza-like illness for strain identification,and submit representative isolates to WHO Collaborating Centres for genetic and antigenic analyses of influenza viruses. The WHO CCs jointly with key national laboratories are involved in registration and quality control of influenza vaccines (Australia, United Kingdom, United States) and collaborate annually on serological studies to obtain evidence as to whether the current vaccines induce satisfactory antibody levels to new epidemic strains.

Twice a year, WHO organises a consultation with the Directors of the WHO Collaborating Centres and representatives of key national laboratories to review the results of these laboratory and clinical studies and make recommendations on the composition of the influenza vaccine (February: northern hemisphere; September: southern hemisphere). Immediately after this consultation WHO informs representatives of pharmaceutical companies on its decisions which are published in the press and the WHO Weekly Epidemiological Record. WHO collaborates with key national licensing agencies on the provision of viruses for vaccine production as well as vaccine potency testing reagents.

What are the three influenza strains identified by WHO for inclusion in the Southern Hemisphere vaccine in 2006?

A/New Caledonia/20/99 (H1N1)-like strain
A/California/7/2004 (H3N2)-like strain
B/Malaysia/2506/2004-like strain

What is the difference between Northern Hemisphere and Southern Hemisphere vaccine?

The most recent Northern Hemisphere season (2005-6) vaccine did not contain the B/Malaysia strain, and the manufacture for the next Northern Hemisphere season 2006-7 has only just begun.

Do flu vaccinations 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 if I have a vaccination?

Influenza vaccine cannot give you the flu as it does not contain live vaccine. However you could still get a strain of influenza circulating in the community that is not in the vaccine you have been given.

What is influenza?

Influenza is a highly infectious illness caused by a virus.

What are the symptoms?

Influenza has a sudden onset and is accompanied by some or all of the following symptoms:

• Fever and chills
• Cough
• Body aches and pains
• Fatigue
• Headache

How can I tell the difference between a cold and influenza?

Influenza makes people feel miserable and is much more serious than 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. Those affected can also suffer from shivering attacks, muscular pains, headaches a dry cough, possible vomiting and there can be complications like pneumonia. 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 killed 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 it 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 if I have a vaccination?

Influenza vaccine cannot give you the flu as it does not contain live vaccine.

Summary of 2005 Influenza statistics

In 2005, there were a total of 528 hospital admissions for influenza. This compares with 430 admissions in 2004 and 593 in 2003.

In 2005, New Zealand experienced an influenza B epidemic in school aged children in the North Island. The epidemic was associated with significant morbidity, as illustrated by media reports of significant school absenteeism. In some schools, particularly in Wellington and Auckland regions, the school absenteeism rate reached more than 20% in June. One Wellington school was closed due to the high rate of respiratory illness. During this epidemic, three children died from complications from influenza B/HongKong/330/2001 infections:

In the years 1990-98 307 people died from influenza, and in 1996 (the year with most deaths) 94 people died from influenza. However, the real mortality rate is likely to be much higher.

Last year it is estimated that 47,000 people experienced influenza.

How are the statistics collected?

There are two parts to the influenza surveillance systems in New Zealand – general practice (GP) surveillance and laboratory-based (mainly hospital) surveillance.

General Practice Surveillance

The 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 (PHSs).

Normally, sentinel surveillance operate from May to September. However, in 2004 due to the late influenza activity it was extended to October with agreement from the Ministry of Health, PHSs, and local virology laboratories. Local surveillance co-ordinators recruit general practices within their region to participate on a voluntary basis. Where possible, the number of practices recruited is proportional to the size of the population in each health district covered by the PHS (approximately 1:50 000 population). Participating GPs are asked to record the number of consultations for influenza-like illness each week and the age group of each of these suspected cases on a standardised form.

Each practice is also asked to collect throat or nose swabs from patients seen with an influenza-like illness each week. The swabs are 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 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’s virology laboratory. Both the ESR and Auckland hospital laboratories are designated WHO National Influenza Centres.

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.

About Influenza Vaccination

Influenza vaccination is the primary method for preventing influenza and its severe complications. In New Zealand, inactivated influenza viral virus vaccines, containing the World Health Organization (WHO) recommended Southern Hemisphere strain composition, are available each year.

How effective is the vaccine considered to be for healthy adults?

Influenza vaccination is 70- 90% effective in preventing infection with influenza A and B viruses in healthy adults when there is a good match between the vaccine and circulating influenza strains.

How effective is influenza vaccine for those at ‘high risk’?

Although influenza vaccines are not totally effective in preventing infection, they are highly effective in protecting those at greatest risk - the elderly and immunocompromised - against the severe consequences of influenza infection.

Studies have shown that in the elderly, influenza vaccination reduces the number of pneumonia cases by 53%, hospitalisation due to respiratory illness by 50% and the total deaths occurring during the influenza season by 68%.¹ These benefits have also been shown in others with certain ongoing medical conditions.²

Despite failure to fully protect all ‘high risk’ people, vaccination is a highly effective means of protecting the majority of them and in reducing disease severity in others.³

Ensuring that healthcare professionals are vaccinated themselves provides additional protection for those at ‘high risk’ in health care settings.³

How long after vaccination does it take for antibodies to be produced?

It takes up to two weeks for the vaccine to give full protection, which will last in healthy adults throughout the influenza season.

How long does the vaccination last?

Protection should last throughout the influenza season and re-immunisation within 12 months is not usually necessary.

Why is influenza immunisation needed every year?

Annual vaccination is required as influenza A and B viruses are continually evolving (called antigenic drift). The vaccine is reformulated to contain the most up to date composition of viral antigens to provide optimal protection.

Who should not receive the vaccine?

Patients with known hypersensitivity to egg protein or feathers should in most cases not receive influenza vaccine (consider seeking specialist advice in some ‘high risk’ patients). The vaccine, although purified, is produced in hens’ eggs and may contain residual egg protein. Gentamycin is also a vaccine constituent, and patients with known hypersensitivity should seek specialist advice. Information regarding the vaccine components is located in the manufacturers package insert.^4,5. Such patients could consider the use of specific influenza treatments, such as Tamiflu®⁶ should they get influenza when influenza is prevalent in the community.

Patients with acute febrile illness should not be vaccinated until their symptoms have abated.

The incidence of Guillain-Barrée Syndrome (GBS) among the general population is low, but persons with a history of GBS have a substantially greater likelihood of subsequently experiencing GBS than persons without such a history. Whether influenza vaccination specifically increases the risk for recurrence of GBS is unknown. The US Advisory Committee on Immunization Practices (ACIP) ⁷ recommends avoiding the vaccination of persons who are not at high risk of severe influenza complications and who are known to have experienced GBS within 6 weeks after a previous influenza vaccination, as being prudent.

Although data are limited, for the majority of persons who have a history of GBS and who are at high risk for severe complications from influenza, the established benefits of influenza vaccination justify yearly vaccination.

What are the possible known adverse responses following influenza immunisation?

Influenza vaccine is well tolerated; however some people have side effects following vaccination. These can include systemic symptoms such as fever, malaise and myalgia, and can occur in around 1% of adults.⁸

These symptoms are also more likely in children who have not previously been exposed to the vaccine or virus..⁸

Local reactions, including redness and induration at the injection site, may persist for one to two days in 10–64% of recipients, but these effects are usually mild..⁸
Vaccinators need to emphasise to recipients that:

• The vaccine is inactivated and cannot cause influenza
• Many other viruses are present during the autumn, and coincidental infection is possible after immunisation
• Local reaction and mild systemic symptoms may be expected for a day or two after immunisation
• Side effects associated with influenza vaccination are minor compared to life-threatening complications that may follow influenza.

Any adverse event following influenza vaccination should be reported to the Centre for Adverse Reactions Monitoring (CARM). Vaccine safety is paramount.

Can you get influenza from the vaccine?

No. The vaccine has been made from virus that has been concentrated, inactivated then broken apart. It cannot cause influenza, as the vaccine does not contain any live viruses.

When vaccinated, the body responds to the vaccine by producing an immune response. This immune response can also include systemic symptoms such as fever, malaise and myalgia as discussed above.

Many other types of respiratory viruses (see below), apart from influenza, circulate during the winter months, and influenza vaccines do not protect against these. Most of these viruses cause milder infections (e.g. the common cold) and do not pose the same threat to the ‘high risk’ population and should not be confused with influenza. Certain other infections may, on occasions, produce influenza-like symptoms and quite severe illness, leading to the statements that the vaccine is ineffective.

Children, Pregnancy, and the Immunocompromised Patient

Is influenza vaccination recommended for healthy children?

Influenza vaccine is licensed for use in children aged 6 months and older.

While children bear the brunt of most influenza outbreaks or epidemics, and are the major ‘spreaders’ in the community, influenza in this age group is not usually a life threatening condition. Our current vaccination strategy is to protect individuals at ‘high risk’ of developing complications, rather than controlling the spread of influenza.
Children are recommended and are eligible for funded vaccine:
When they are in one of the ‘high risk’ groups. This includes pre-term infants who develop chronic respiratory disease. It is recommended they be offered vaccination at 6 months of age. Refer to page 68, Immunisation Handbook 2006⁸ (or see the eligibility table above)
The following are situations where vaccination of children should be considered:

• When they are in a household living or in frequent contact with a ‘high risk’ individual
• When in a boarding school or institutional environment.

Recommended influenza vaccine doses for children ^{8 ,9}

Age	Dose	Number of doses
6-35 months	0.25 mL	1 or 2*
3-8 years	0.5 mL	1 or 2*
> 9 years	0.5 mL	1

* Two doses separated by at least four weeks if the vaccine is being used for the first time.


Children aged 6–35 months should receive 0.25ml, and children aged over 3 years should receive the full 0.5mL l dose (however these recommended dosages for young children at different ages may vary between vaccine manufacturers). All children under 9 years of age should receive 2 doses separated by at least 4 weeks, if they have never been previously vaccinated with the influenza vaccine⁸. Influenza vaccine tends to be more reactogenic in young children so prophylactic paracetamol before and/or after immunisation can be helpful in reducing associated side effects.

Some countries do recommend the vaccination of healthy children. The 2004 US Advisory Committee on Immunization Practices (ACIP) recommendations³ include healthy children aged 6–23 months Universal influenza immunisation of all healthy infants, six to 24 months of age, has recently been introduced in the United States¹⁰. This is because children 0-23 monthsyoung children have the highest rates of infection and mortality second only to the elderly.

Should vaccination be carried out during pregnancy?

The Immunisation Handbook 2006.⁸ recommends that influenza vaccine should be offered to pregnant women with a medical condition. The vaccine should be given before the influenza season. Women without a risk condition, who will be beyond the first trimester of pregnancy (14 weeks gestation) during the influenza season should also be vaccinated. ^8,9 The ACIP recommends that, because of an increased risk of influenza-related complications, women who will be pregnant during the influenza season should be vaccinated.⁷

When is the best time to vaccinate the severely immunosuppressed?

The optimal time is prior to the initiation of chemotherapy or radiation treatment.¹¹ Following cessation of cancer chemotherapy, normal immune responses return after about 30 days. A medical specialist’s advice should be sought.

Why is it important to (‘ring fence’) protect the people who care for the immunosuppressed?

The protective effectiveness of influenza vaccination is likely to be low in this group of patients, thus additional preventative strategies are needed. Nosocomially acquired influenza is their most likely route of infection so “ring-fencing” of such patients by immunising family members and hospital staff should be considered.⁸

Should anti-influenza drugs be used as a substitute for influenza vaccination?

Anti-influenza drugs should not be seen as an alternative to vaccination in the ‘high risk’ population because:

• Vaccination is a simple one step process, which is effective for the whole season while drug prophylaxis is feasible for only limited periods, and requires daily dosage in order to be effective
• Prevention of infection is far preferable to treatment in the ‘high risk’ groups as serious damage may be done during the early stages of infection and commencement of treatment may not be in time to prevent serious outcomes
• With increasing influenza awareness, the real time dissemination of influenza surveillance data, and access to rapid diagnostic assays, antivirals will be more widely used in hospital and institutional settings for outbreak control.

The Importance of Vaccination for Healthcare Providers

Should doctors, nurses and other healthcare workers be vaccinated against influenza?

Yes. Staff in routine contact with patients should be encouraged to be vaccinated, especially those caring for the ‘high risk’ groups. Patients in hospital, especially during the influenza season, are at increased risk of nosocomial influenza infection.³

Healthcare workers, when they are clinically or sub-clinically infected, can transmit influenza virus to people ‘high risk’.³

It makes good sense for nursing and other medical staff to be immunised to protect the patients they are caring for.

Knowledge and Attitudes Towards Influenza Vaccination

A study¹² of the knowledge and attitudes towards influenza vaccination among general practitioners, practice nurses and people aged 65 years or over was carried out in four regions of New Zealand during 2001/02.

How many health professionals and those aged 65 years and over received the influenza vaccine in the study?

• 64–68% of health professionals
• 76% of people aged 65 years and over

Why did health professionals and those aged 65 years and over in the study choose to receive influenza vaccination?

• Most commonly they chose to receive the influenza vaccination because the vaccine protects against influenza
• The next most common reason was that these people were concerned about getting influenza and its complications, and they believed that the influenza vaccine prevents serious disease.
• 67% of those aged 65 years and over recall their health provider recommending the influenza vaccine – of these 83% chose to receive the influenza vaccine. Only 63% of those that could not recall a reminder from their health provider received the influenza vaccine.

What reasons did people in the study give for not receiving the influenza vaccination?

• They believed they did not need it as they rarely got sick.
• Believed they were unlikely to get influenza
• They were concerned about the side effects of the vaccine.
• Just over 50% of respondents mistakenly believed that they could get influenza from the vaccine, or that they could get sick from the vaccine.

It is important that people are aware that influenza can infect anyone. The vaccine is safe and it is not possible to get influenza from the vaccine.

Who do I contact if my question is not answered here?

Please call your doctor or practice nurse. For further information you can also contact the Immunisation Advisory Centre (IMAC) on 0800 IMMUNE (0800 466 863) or, contact your local immunisation facilitator or coordinator, or see the National Influenza Strategy Group (NiSG) website www.influenza.org.nz..

References

1. Gross PA, Hermogenes AW, Sacks HS, Lau J, Levandowski RA. The efficacy of influenza vaccine in elderly persons. A meta-analysis and review of the literature. Ann.Intem.Med. 1995; 123(7):518-27.
   
2. Jennings LC, Huang QS, Bonne M, et al. Influenza surveillance and vaccination in New Zealand, 1990-1999. NZ Health Report 2001
   
3. Nichol KL Goodman M Cost effectiveness of influenza vaccination for healthy persons between age 65 and 74 years Vaccine 2002 May 15 20 Suppl 2:S21-4
   
4. Fluvax® Prescribing Information
   
5. Vaxigrip® Prescribing Information
   
6. Tamiflu® Data Sheet, dated 21 September 2005. Roche Products (New Zealand) Ltd, 8 Henderson Place, Te Papapa, Auckland
   
7. Centers for Disease Control and Prevention. 2005. Prevention and Control of Influenza; Recommendations of the Advisory Committee on Immunization Practices (ACIP) MMWR:54;(RR08);1-40 http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5408a1.htm
   
8. Ministry of Health. Immunisation Handbook. Ministry of Health 2006.
   
9. American Academy of Pediatrics. 2003. In LK Pickering (ed) Red Book: Report of the Committee on Infectious Diseases (25th edition), Elk Grove Village, IL: American Academy of Pediatrics.
   
10. US Centers for Disease Control and Prevention. 2004. Prevention and Control of Influenza; Recommendations of the Advisory Committee on Immunization Practices (ACIP) MMWR:53 (RR-6):1–40.
    
11. Elting LS, Wimbey E, Lo W, et al. 1995. Epidemiology of influenza A virus infection in patients with acute or chronic leukemia. Support care Cancer 3:198-202
    
12. Brunton C, Weir R, Jennings L. 2005. A study of the knowledge and attitudes about influenza vaccination amongst general practitioners, practice nurses, and people aged 65 years and over. NZ Med J 118:1214. URL: http://nzma.org.nz/journal/118-1214/1434.

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Related information:

Influenza page

Communicable diseases



Page last updated: 25 October 2007