Dr Angela Murphy explains why and how a flu vaccine can save millions of lives.
Every year more than 6000 people die from influenza (flu) in South Africa. Thousands more are hospitalised and many lose income from being absent from work.
What is influenza?
It’s a viral illness which has a sudden onset, causing fever, sore throat, body pains and a headache. In most otherwise healthy adults, it will be an uncomplicated illness and the person will recover within a week.
However, certain high-risk groups, as discussed below, are at risk of more severe infection. Although flu can be treated, it is much better to prevent it. The most effective prevention available is the flu vaccination.
Flu vaccination
A vaccination is designed to get the body to produce an immune response so that when an infection occurs, the body can easily fight against it.
The flu vaccination is an inactivated vaccine i.e. there is no live virus so it is impossible for the vaccine to cause flu.
The flu virus is constantly changing and so the vaccine must be updated every year. The current vaccine contains three different strains of flu which the World Health Organization has predicted will cause this season’s outbreak.
Getting vaccinated
Flu season in South Africa runs from May to September. Ideally vaccination should be done in April as it takes around two weeks for immunity to develop. If during this period, a person is exposed to flu, they may indeed get ill as they would not yet be immune. This illness is not due to the flu vaccine.
It is possible to give the vaccine later in the year, especially in the high-risk groups mentioned below. Preferably, everyone over the age of six months should receive the vaccine, but due to resource constraint the Department of Health has highlighted high-risk groups who are a priority for flu vaccination.
High-risk groups:
- Pregnant women.
- Patients infected with HIV.
- Patients with underlying chronic disease, especially diabetes, lung diseases and heart disease.
- People > 65 years of age.
Department of Health’s goal
If resources allow, the Department of Health would also like healthcare workers, residents of Old Age Homes, Institutions and Rehabilitation Centres as well as children on Aspirin therapy, aged between six and 18 months, to receive the vaccine.
The dose of flu vaccine recommended by the National Health Laboratory Services is as follows:
- Adults 0.5ml IMI single dose
- 3 years – 8 years 0.5ml IMI 1 or 2 doses*
- 6 months-2 years-0.25ml IMI 1 or 2 doses*
*Two doses should be administered ≥ 1 month apart during first year of vaccination, thereafter one dose.
Side effects of flu vaccine
The vaccine is safe to take in most people but should be avoided if there is a history of severe allergic reaction. Most flu vaccines today are produced using an egg-based manufacturing process and thus contains a small amount of egg protein, called ovalbumin. The Centre for Disease Control in Atlanta, USA recommends the flu vaccine to be safe for most patients with history of egg allergy unless the reaction was life-threatening, i.e. an anaphalaxic reaction. They found in a recent study that the anaphylaxis rate after all vaccines is 1,31 per one million vaccine doses given.
It also better to recover from any flu-like symptoms before receiving the vaccine. Most people will experience little more than the discomfort of the injection. Sometimes there may be a more significant local skin reaction, hoarseness, red eyes, aches and pains, itching and headache. These side effects should not last longer than two days.
How a flu epidemic starts
The flu virus often mutates and different strains arise. When populations are not immune to these new strains, then epidemics arise.
Less commonly, a new strain appears to which most people around the world have no immunity. In this instance, a pandemic arises. The worst of these pandemics started 100 years ago in March 1918 where the Spanish flu killed millions. With today’s improved medical care and availability of vaccines that type of tragedy should not be seen.
Flu vaccine studies
A recent study at Bergen University, in Sweden, confirmed that having the flu vaccine annually improved immunity in the body. The investigators, led by Rebecca Cox, showed that people who had repeated annual flu vaccines had much greater disease-fighting capability than those who did not get the vaccine.
The effects of flu on a diabetes patient
People living with diabetes will know how infection can cause a significant deterioration in their sugar control. Having flu elevates blood sugars due to increased resistance to insulin, and with dehydration it is possible to develop a diabetic ketoacidosis. Paradoxically, hypoglycaemia may also be a feature of flu because of high fevers, sweating, poor appetite and vomiting.
Flu vaccination remains the most effective way to prevent all of this. There are 80% less hospital admissions in diabetic patients who get flu if they have also had the flu vaccine.
Remember, by being vaccinated and becoming immune to the flu, you cannot pass it on. Vaccinate today and keep healthy this winter.
REFERENCES:
http://www.nicd.ac.za/index.php/influenza/
https://www.cdc.gov/flu/protect/vaccine/egg-allergies.htm
http://www.uib.no/en/news/111513/annual-influenza-vaccination-does-not-prevent-natural-immunity
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