Re: flu vaccination
anonymous

Question:
 

I'm currently looking in to the use of the flu vaccination and wondering whether anyone knows some really good medical sources with pure facts.

My Advice:

 

Influenza and Flu Vax

The effects of the Flu and Flu vax in adults pregnancy and children

The flu season is upon us yet again.  The infection control nurse at the children’s hospital I work in has informed me that the first cases of the flu for the season are beginning to present to the hospital.  I have also noticed a few questions on minti about the flu vax so as a result, I have researched the medical data base extensively for safety, recommendations, side effects, myths, truths and effectiveness.  The information is from recent articles, since late 2008 and from sources such as the Centre for Disease Control (CDC)- a 60 page report considering all factors.  I am very aware that there are parents and minti members who are strongly against vaccination of any kind.  My aim is to present the latest research based information from a medical data base to assist parents in making informed decisions.  So I hope a few parents may get something out of this article.

First- What is the Flu?

Influenza is a virus of the respiratory tract that causes fever, chills, malaise (body aching), coughing, runny nose and sore throat.  There are 3 types, being influenza A, B and C, with A being the most common and causing the most severe symptoms.  The onset of influenza is quite abrupt- within the same day of starting symptoms (sometimes within a few minutes), you may be very unwell and bed bound with it.  Some people mistake the common cold for the flu, truth is- if you have the flu, you know it.  The common cold, in comparison, is not as severe and takes several days to reach its peak.  The flu has an incubation period of 1-2 days, when you may be infectious but not displaying symptoms.

Influenza is a severe and sudden infection.  Prior to the development of the flu vax, 35 million deaths worldwide were attributed to the 1918 influenza pandemic (Foster, 2008, p.409).  So yes, the flu can be deadly!  More recently, in the 2007-2008 United states flu season, 65 children died of laboratory confirmed influenza (Foster, 2008, p.409). (now that’s a tragedy, when it could have been preventable).

Influenza is severe enough to cause admissions to hospital, especially for children and the elderly.  Infection with influenza may lead to complications of sinusitis, ear infections, bronchitis, croup in babies, encephalitis (brain infection) viral pneumonia or bacterial pneumonia, which may be life threatening.  Children (especially those with asthma, cardiac conditions, chronic lung disease or other respiratory conditions), the elderly, pregnant women and immunocompromised people are at higher risk of complications.  Influenza in pregnancy can cause fetal malformation (Zaman, et al, 2008, p 1555).

IS IT THE FLU? (table HMHW, 2008, p.6)

Flu: thin nasal dischage, high fever, severe cough, severe muscle aches, severe headaches, severe fatigue and weakness.  treatment with fluids, sometimes decogestants, sometimes antiviral

Allergy: sneezing, itchy eyes/throat, watery nasal discharge. treatment with antihistamine and decongestants.

Cold: sneezing, watery nasal discharge, mild facial pain/pressure, low grade fever, mild cough, mild muscle aches, mild headache, mild fatigue/weakness.  treatment with fluids, inhaled steam, decongestants, antihistamines.

Sinusitis: thick discoloured nasal discharge, bad breath/ taste in mouth, facial pain/pressure, low to moderate fever, mild cough, mild muscle aches, mild headache, mild fatigue/weakness.  treatment with fluids, inhaled steam, decongestants and antibiotics.

 Influenza is more common in the winter months (Northern hemisphere- November to March, Southern Hemisphere- May to September) and is spread by direct contact/inhaling of infected respiratory secretions, either through coughing sneezing or contact with articles contaminated with these secretions (such as tissues).  In 2007 a study was done which found that in a cool environment and low humidity the flu virus spread much more readily (HMHW, 2008, p.5).  Summer weather protects us from the flu.  In the tropics, where there is no cool/low humidity environment, there is no flu season and although flu may be reported, it is not of epidemic proportions.  To add to this, during winter, individuals are indoors and closer to each other, increasing the risk of the spread.

There are several strains of the virus, and over time they mutate slightly (by changing proteins on the virus’ outer coat), making your own immune system less able to fight the illness, even if you have previous exposure (they change just enough for your antibodies not to recognize them any more).  This is why the flu vax is recommended annually.  Influenza is highly contagious and is responsible for epidemics and pandemics across the world.  Approximately every 4 years there is a ‘bad’ flu season (and a really bad flu season every 10-15 years), with more people hospitalized and more numbers to the epidemic.

Treatment of the flu

Because the flu is a virus, it cannot be treated with antibiotics.  Bacterial complications from the flu may be treated with antibiotics, but the aim is to prevent these complications in the first place.

There are specific anti viral drugs to treat the flu.  Two older drugs- amantadine (symmetrel) and rimantadine (flumadine) have lost their effectiveness.  Two newer drugs- Zanamivir (Relenza) and Oseltamivir (Tamiflu) can ease the symptoms and shorten the illness if administered within the first 24-36 hours of symptoms beginning.  Neither will cure the flu and both have side effects such as nausea, vomiting, wheezing, behavioural abnormalities (HMHW, 2008, p.8).  Antivirals are not recommended/ are unsafe in early pregnancy (Zaman et al, 2008, p.1555).

About Flu vax

The flu vax is designed to stimulate antibodies to a deactivated virus (injectable) so that when the body has exposure to the real virus, the immune system is prepared by being able to recognize the virus and having the right antibody proteins to fight it. 

Because of the ability of the flu virus to mutate, every year The Public Health Advisory Committee on Immunisation Practices updates its recommendations for the composition of the vaccine (1).  In most years, the new flu strain outbreaks in Asia first, which gives the rest of the world an opportunity to develop the vaccine likely to be the most successful at controlling an epidemic (HMHW, 2008, p.5).  Each year, a new vaccine is developed to protect from both an influenza A virus and an influenza B virus in the one vaccine (Fiore, et.al. CDC, 2008, p.9).

When the flu vax is well matched to the season epidemic strain, there can be a 70-90% effectiveness at reducing influenza infection in healthy adults younger than 65 years (Foster, 2008, p.409).  For this reason, healthy adults are encouraged to get the flu vax to prevent the spread to at risk individuals, as the flu vax effectiveness in those individuals is closer to 30-40% (CDC, 2008, cited in Foster, 2008, p.409).  This concept is known as ‘herd’ immunity-where if enough individuals are immunized against a disease, the whole population are less likely to become infected (Foster, 2008, p.410).    

A significant percentage of people refuse to have the flu vaccination because they are misinformed about the effectiveness and potential adverse effects.  The following table is from the AAOHN Journal, Oct 2008 p.410 (Levy, 2008, cited in Foster, 2008):

Common excuses for not receiving the flu vaccine and rationale against these myths:

‘The flu shot gives me the flu’ : This is impossible.  The vaccine is made from a dead virus that is not capable of causing infection.  This myth arose from the 1976 vaccinations given for swine flu that caused 7 cases of Guillian-Barre syndrome, although no proof of cause and effect existed.  Today’s flu vaccine is entirely different and does not carry that risk.

‘My immune system is so strong that I don’t need the flu shot’: Such individuals benefit the most from receiving the vaccine.  Effectiveness is greater in healthy individuals, and they can prevent infecting those who are immunocompromised.  Because the virus changes every year, receiving the flu vaccine annually will keep an individual’s immune system updated.

‘Last year I got the flu shot and had a terrible reaction’: Soreness at the injection site is normal.  Some individuals may experience a low grade fever, meaning that their body is recognizing and responding to the vaccine.  Such reactions last less than 2 days and are less severe than influenza.

‘I don’t like taking shots’: An inhalable flu vaccine exists for healthy individuals between 2 and 49 years of age.  This is a live but weakened virus.

‘Because there is a vaccine shortage, I’ll let others who really need it get it’: This years supply is expected to be plentiful.

Who should have the flu vax (1, and Fiore et.al, CDC, 2008, p.2)

Those with high risk for influenza complications are recommended to have the flu vax including:

People aged 65 years or over

Residents of nursing homes or care facilities

People of any age with chronic medical conditions

Adults or children with chronic pulmonary or cardiovascular conditions

Adults or children who have required treatment for chronic metabolic conditions in the previous year- including diabetes, renal dysfunction, blood disorders

People who are immunosuppressed, through illness or medication.

Those aged 6 months to 18 years on long term asprin therapy due to the risk of developing Reye’s syndrome if contracting the flu.

Health care workers- if you work in health care you are more likely to be exposed, and you may be spreading the infection to at risk populations before you know you have the flu.  I have read reports on some hospitals wanting to make flu vax mandatory for all health care workers.

Members of a household caring for high risk person.

Any woman who will be pregnant or expecting to be pregnant during the flu season

Flu vax in pregnancy and breastfeeding

Flu Vax (injectable) is not only safe in pregnancy but encouraged.  The flu vax protects pregnant women from the flu and also provides a passive protection to the newborn as the mothers’ antibodies are passed through the placenta (Fiore et.al, CDC, 2008, p.12).  Available data shows that the influenza vaccine does not cause fetal harm or affect reproductive capacity (Fiore, et al, CDC, 2008, p.14).  Pregnant women are at risk of influenza complications and are recommended to be vaccinated.  Maternal influenza infection has been associated with an increased risk of maternal hospitalization, fetal malformation and other illnesses (cited in Zaman et al, 2008, p. 1555). The flu mist is not licensed for pregnant women but there is no need to avoid contact with anyone who has recently been vaccinated with the flu mist (Fiore et.al, CDC, 2008, p.28).

Breastfeeding women are also encouraged to have the flu vax.  It is safe in breastfeeding and not only protects the mother, but also protects transmission of the flu to her baby.  Infants and children are at higher risk of influenza related complications and hospitalization if infected (Fiore et.al, CDC, 2008, p.28).  Childhood deaths associated with influenza are most frequent in babies under the age of 6 months (Bhat et al, cited in Zaman et al, 2008, p. 1555).

Flu vax in children

Flu vax is also safe in children.  A study reviewed by the CDC of 215 600 children indicated “no increase in biologically plausible, medically attended events during the 2 weeks after inactivated influenza vaccination, compared with control periods 3-4 weeks before and after vaccination” (cited in Fiore et.al, CDC, 2008, p.14).

Children aged 6 months to 8 years who have never received a flu vax should receive 2 doses separated by 4 weeks (Fiore et.al, CDC, 2008, p.9-11)

Flu vax injectable (TIV) versus Flu mist (LAIV) – all following info in this section from Fiore et al, CDC, 2008.

There are 2 types of influenza vaccination available- one is the traditional injectable vaccine and the other in a newly developed intranasal inhaled spray (or flu mist).  The injectable TIV contains killed virus and cannot cause influenza symptoms as a side effect (p.9).  It is recommended for anyone aged 6 months or older (Table 1 p.10).  Side effects include pain at the injection site, low grade fever.

The inhaled LAIV is a live, attenuated virus composition that can cause mild signs and symptoms such as runny nose, nasal congestion, fever, sore throat.  It is licensed for people that are not pregnant and aged 2-49 years of age (p.9).  It should not be given to immunosuppressed people requiring a protective environment, or people caring for immunosuppressed people, people with medical risk factors for flu-related complications, or children with asthma or wheezing within the previous year (Fiore et.al, CDC, 2008, table 1, p.10).

Who shouldn’t have flu vax

Anyone with a history of allergies to egg or other vaccine components should not have the fluvax as it may cause an anaphylactic reaction (1).  Prophylactic antivirals may be administered to these people if they have had exposure to the flu.

Anyone who has a moderate to severe acute febrile illness should not be vaccinated until the symptoms are gone (Fiore et.al, CDC, 2008, p.29).

Anyone who has had a severe reaction to flu vax in the past.

Anyone who has developed Guillian Barre syndrome within 6 weeks of a prior influenza vaccine.

Controlling Flu, other than Flu vax

Hand washing- The best way to control the spread of any illness!

Distance- The flu is contagious within 3feet/1m of an infected person (HMHW, 2008, p.7)

Wear a mask- for high risk protection.  N95 respirator masks are recommended (HMHW, 2008, p.7).

Protect others- get vaccinated, don’t go to work or school and expose others, use a tissue for sneezing and coughing and dispose of it appropriately, don’t visit high risk populations (such as hospitals or young children).

Quit smoking- smokers are vulnerable to the flu and its complications (CRH, 2008, p.3)

Get enough sleep, eat well, exercise regularly and reduce stress (CRH, 2008, p.3)

Don’t rely on herbs or supplements- none have been scientifically proven effective at preventing the flu (CRH, 2008, p.3).

When the flu vax trolley comes to my ward, I will be rolling up my sleeve- not only to lower my chances of getting sick (who wants to have the flu and be responsible for 3 young kids), but to protect my children and my succesptible patients.

References

1-     Porth, C “Pathophysiology: Concepts of Altered Health States” 5th edition, 1998 Lippincott-Raven Publishers, pp505-7. 

2-     Hockenberry, Wilson “Wong’s Nursing Care of Infants and Children” 8th edition, 2007 Mosby, pp1324-1325.

Author not stated. ‘Influenza: How to Prevent and Treat a Serious Infection’ Harvard Men’s Health Watch (HMHW), 2008, Oct vol. 13, no.3 pp5-8

CRH, ‘Flu Shot, More Important Than Ever’, 2008, Consumer Reports on Health, Vol. 20, no.11, p.3.

Fiore, AE; Shay, DK; Broder, K; Iskander, JK; Uyeki, TM; Mootry, G; Bresee, JS; Cox, NJ; National Centre for Immunization and Respiratory Diseases.  Influenza Division.  ‘ Prevention and Control of Influenza: Recommendations of the Advisory Committee on Influenza Practices (ACIP), 2008’, MMWR: Morbidity and Mortality Weekly Report, 2008, Aug 8th, vol 57, no.RR-7, pp. 1-60.

Foster, D, ‘Influenza Vaccination’, AAOHN Journal, 2008, Oct vol.56, no.10, pp409-11.

Zaman, K; Roy, E; Arifeen, SE; Rahman, M; Raqib, R; Wilson, E; Omer, SB; Shahid, NS; Breiman, RE; Steinhoff, MC, ‘Effectiveness of Maternal Influenza Immunization in Mothers and Infants’, 2008, New England Journal of Medicine, vol. 359, no.15, pp.1555-64.

CDC recommendations: http://web.ebscohost.com/ehost/pdf?vid=118&hid=101&sid=fc45b370-9f5f-445e-a490-ddb4b9c514ef%40sessionmgr108 –I apologise if link does not work, sometimes I get timed out of the data base.