Now that flu season is here, it is time to start considering getting vaccinated against influenza in the UAE
18 September 2023| Last updated on 18 September 2023
What is influenza and why should we get vaccinated?
Influenza is an acute viral infection of the airways (nose, throat and lungs). There are three types of influenza known as A, B and C.
The A and B varieties tend to cause most of the illness. The infection spreads very easily by droplets in the air or by direct contact with airway secretions of an infected person. The time from being infected to getting symptoms is usually between one and three days. The virus can be found in nose and throat swabs from one day before the onset of symptoms to four or five days after.
It is estimated that seasonal influenza affects 5 to 10% of the world’s population.
Typically, influenza causes a sudden onset of fever, chills, headache, muscle aches and extreme fatigue. Other common symptoms are dry cough, sore throat and a stuffy nose. In most healthy people the infection is unpleasant but usually settles on its own within two to seven days.
Complications with influenza include chest infections such as bronchitis and pneumonia, ear infections (especially in children), and more rarely inflammation of the brain (meningitis and encephalitis). It can also worsen pre-existing disease. Sadly, deaths also occur with each epidemic.
The best way to reduce illness and these complications is by annual vaccination
Who are at risk of being infected with influenza?
Some people are at a higher risk of becoming more seriously ill. These tend to be the elderly, young children, pregnant women, people with chronic long-term conditions (such as asthma, diabetes and heart disease), and people with weakened immune systems.
When does influenza typically occur?
Influenza generally occurs in regular annual epidemics, typically between November and April in the Northern hemisphere. It takes ten to fourteen days to develop effective protection having received the vaccine, hence it is best to be vaccinated before this period.
The flu virus changes over time which means a new vaccine is needed each year. The vaccines are prepared using virus strains that are recommended by the World Health Organisation (WHO) and cover the strains of types A and B that are predicted to cause problems in that year.
How are influenza vaccines made?
Most of the influenza vaccines are prepared from viruses grown in embryonated hens’ eggs and are inactivated so they cannot cause influenza.
One vaccine contains live viruses that have been attenuated (weakened) and adapted to cold so that they can only replicate at the lower temperatures found in the nasal passage. These live viruses cannot replicate efficiently elsewhere in the body but may cause mild symptoms of a cold.
How is the vaccination administered?
The vaccine is injected into the muscle in the upper arm, usually the non-dominant side.
In infants it is given into the thigh muscle. Children from 6 months to 9 years who have not received the influenza vaccine previously would normally be offered a repeat vaccination after a month.
What are the possible side effects of an influenza vaccine?
A minority of people can have fever, headache and malaise which typically start 6 to 12 hours after vaccination. They are usually mild and settle down after 1 to 2 days.
It can be helpful to take paracetamol to ease these effects. Some people may get injection site reactions such as pain, swelling and redness. These also tend to settle quickly.
Can vaccination give me the flu?
Most flu vaccines are made from inactivated influenza virus and so cannot cause clinical influenza.
If someone is vaccinated and was already incubating the virus or exposed just after vaccination, they can still develop flu. There are of course many other viruses that mimic the symptoms of flu that the vaccine will not protect against.
Is it safe to have the vaccination in pregnancy and whilst breast feeding?
The inactivated vaccination is considered safe in pregnancy and helps to reduce the risk of complications in pregnancy caused by flu.
"A review of studies on the safety of influenza vaccine in pregnancy concluded that inactivated influenza vaccine can be safely and effectively administered during any stage of pregnancy," said Dr. Simon Lee, Consultant Family Medicine at Mediclinic Creek Harbour in Dubai.
He added: "A number of studies show that influenza vaccination during pregnancy provides protection (with passive immunity) against influenza to infants in the first few months of life following birth."
It is also safe to have when breast feeding.
What if I have reaction to eggs?
Because most vaccinations are produced using hen eggs there is a slight risk for those who are allergic to eggs.
Some people have a food intolerance to eggs and get things like tummy bloating. This is distinct from allergy and it is fine to have the flu vaccination in these cases.
Those who are allergic to eggs may receive the vaccine but depending on the severity and type of allergic reaction the vaccine may need to be administered in a hospital setting.
So remember the best way of reducing the risks of the flu is to get vaccinated in the coming weeks so that you have built up protection for when the flu season starts.
Authored by Dr. Simon Lee.