What is the influenza virus?
Influenza viruses are enveloped RNA viruses, which are divided into three types “A, B and C”. The first two are involved in significant human diseases.
For influenza viruses (type A), there are many subtypes of it but usually one or two circulate more frequently in the human population at any given time. That is the reason why seasonal influenza vaccines include two subtypes of influenza A viruses and one type of influenza B virus, which has no subtypes. Hence, it is called trivalent Influenza vaccine (TIV).
Influenza viruses are characterized by numerous mutations, causing a change in the viral structure every year. Therefore, seasonal influenza vaccines structure changes annually to match the circulating strains.
So that last year flu vaccine may not be suitable for this year.
02. What is the seasonal influenza disease?
Seasonal influenza causes severe illness and, at times, life-threatening complications. Moreover, seasonal influenza annually affects 600 million individuals and kills up to 500,000 ones. Hence as mentioned by the European Health Council, seasonal influenza takes more lives annually than road accidents do. The incubation period of influenza ranges from 1-4 days. The symptoms normally start to appear from the second day of infection. Influenza illness is characterized by sudden fever, sore throat, severe headache, myalgia, chills and extreme fatigue. Some of these symptoms can distinguish influenza from normal common colds.
03. Is there a vaccine to protect against seasonal influenza?
Seasonal influenza vaccine is inactivated and contains parts of the influenza viruses, which protect, Allah willing, from the existing three strains of this season. The three strains included in the vaccine are those recommended by the World Health Organization (WHO) for the winter season annually.
04. Does influenza vaccination protect from common colds?
Influenza vaccine may indirectly protect from common colds. And that because the flu weakens the immune system temporarily, which may make a person susceptible to infection with microbes and other viruses that infect the respiratory tract, like common cold and others.
05. How does influenza vaccination work?
By giving the vaccine, we are injecting the person with parts of the most commonly circulating flu viruses, which will stimulate the immune system to produce antibodies against these strains. This process may take two weeks. After this period, a person acquires protection against these strains.
06. Who are at increased risk of Influenza complications?
Although all age groups are affected by influenza, rates of serious illnesses, complications, and deaths are the highest among people with certain chronic medical diseases or other conditions. These conditions include pregnant women, persons with chronic lung or heart diseases, diabetics, patients with weakened immune system (congenital or acquired) and neurological disorders, as well as residents of nursing homes and long-term care facilities.
07. Who should be vaccinated?
The Saudi Ministry of Health announced that the following groups are among the groups targeted by and recommended for seasonal Influenza vaccination every year.
- All Diabetics
- Asthmatics and patients with chronic obstructive pulmonary disease (COPD).
- Patients with all types of chronic cardiac diseases.
- Patient with chronic renal diseases.
- Patients with chronic liver diseases.
- Neurological Disorders.
- Immune deficiency patients Congenital or acquired (due to cancer or steroids).
- Morbid obesity.
- Pregnant women.
- 6 m - 18 yr on long term Aspirin therapy.
- Children aged 6month to 5 years.
- Persons older than 50 years.
- All health care workers ( doctors, nurses and technicians).
Also, as part of its efforts to combat the flu disease, the Saudi Ministry of Health strongly recommends pilgrims to get vaccinated against seasonal flu before performing Hajj.
The Advisory Committee for Immunization Practices “ACIP” (the highest authority controlling vaccination policies in the US) recommends influenza vaccination for the same groups.
08. Is influenza vaccine safe during pregnancy and lactation?
The type of influenza vaccines adopted by in MOH can be used during pregnancy and lactation and it is strongly recommended for pregnant women.
09. Should pregnant women take the influenza vaccine? And why?
Yes, pregnant women should take the influenza vaccination to protect themselves during pregnancy and to protect their babies until the age of six months after birth (it is not approved for children less than 6 months). Studies have shown that giving flu vaccine to pregnant women reduces the rate of babies hospitalization by up to 92% compared to the babies of pregnant women who do not take the vaccine during pregnancy.
10. Is influenza vaccines safe and effective for patients with chronic illness “diabetes, asthma or heart disease”?
It is not only safe and effective but, it is also strongly recommended for them.
11. Can I get seasonal flu even though I got flu vaccine this year?
The vaccine does not protect completely. Still, there is a possibility that you could get flu even if you got vaccinated but it is less than those unvaccinated. The protection depends on several factors, including: the age and health status of the person being vaccinated, and also the similarity or match between the virus strains used in the vaccine and those circulating in the community (protection reaches up to 90%).
12. Why should I take a flu vaccination?
The vaccine is necessary to protect yourself from getting flu. Also, to protect your family and people around you especially those at risk for flu complications. Influenza vaccination may make your illness milder and reduce the risk of hospitalization due to complications and deaths.
13. Why is the influenza vaccine taken annually?
It is an annual vaccine because its composition is modified each year to match virus strains circulating annually in the northern hemisphere where Saudi Arabia is located and in the southern hemisphere as well. There are two types of vaccine for both hemispheres, but they may be similar during some seasons according to the circulating strains.
14. When should I get vaccinated?
The flu vaccination should begin soon after vaccine becomes available, ideally by October. However, as long as flu viruses are circulating, vaccination should continue to be offered throughout the flu season even in January or later.
15. Where can I get flu vaccine?
The flu vaccine is available free at all MOH hospitals and primary health care centers.
16. Who is prohibited from taking the vaccine?
There are some people who are not allowed to take the vaccine only after consulting a doctor, including:
- Those with severe egg allergy
- Those with previous history of severe allergy to influenza vaccine
- Those with history of Guillain-Barre syndrome after taking the vaccine
- Children under the age of 6 months (vaccine is not approved for this category)
- People with very high or moderate temperature, but they can take the vaccine after their temperature resolved.
17. Are there temporary contraindications for flu vaccination?
Like the other vaccines, flu vaccination should be postponed if there is acute illness, especially if it was associated with moderate or high grade fever.
18. What are the adverse effects of vaccine?
Influenza vaccination is safe, but it is possible to have some local reactions for not more than 48 hours, and resolve without any treatment, including:
- Mild redness or swelling at the injection site
- A slight rise in temperature
- Minor body aches
- Sore throat
19. Does the flu vaccine protect from bird flu?
Bird flu (H5N1) is caused by another strain of influenza other than those causing seasonal flu. There is no human to human transmission, but the virus can be transmitted through direct contact with the affected or dead poultry that were infected with bird flu. It is associated with high mortality (up to 60%) in human. Flu vaccine does not contain the bird flu strain and does not protect from infection. But by getting the influenza vaccine, you will be protected from getting influenza which will protect you from getting other infections.
20. Why is the influenza vaccine taken on annual and seasonal bases?
It is an annual vaccine because its composition is modified each year to match annual circulating influenza virus strains. It is also a seasonal vaccine because it should be administered during the influenza season that starts in September and ends in March every year in the northern hemisphere where Saudi Arabia is located.
21. Who specifies the composition of influenza vaccines every year?
It is specified annually by WHO to ensure that the vaccine is effective against the circulating strains. These strains are isolated annually through global surveillance networks, which were created in 1948 and located in different countries worldwide. This process is repeated each year.
22. What is the composition of the type of influenza vaccines available in MOH hospitals?
The vaccine available in KSA is a trivalent influenza vaccine (TIV), containing inactivated antigens for two different subtypes of influenza viruses (type A) and one subtype of influenza viruses (type B). When the vaccine is injected into the human body, it stimulates the human immune system to produce influenza virus antibodies. These antibodies will prevent influenza infection in case of exposure to the virus.
23. What is the storage temperature of influenza vaccine?
As most other vaccines, the influenza vaccination should be stored at 2-8 c and kept away from light. It shouldn’t be frozen. But before usage, it should be allowed to reach room temperature.
24. What is the route of administration of influenza drug?
The vaccine is mainly used through the intramuscular injection in the arm. For children younger than one year vaccine is given in the thigh.
25. Is there any interaction between the type of influenza vaccines available in MOH hospitals and the other vaccines?
No, flu vaccines can be given with other at the same time.
26. Are there any overdose effects?
No, the overdose is unlikely to leave any unwanted effect.
27. What is the pharmaceutical presentation of the type of influenza vaccines available in MOH hospitals?
It is presented in 0.5ml liquid pre-filled ready-to-use syringe.
28. Is there any difference between children’s and adult’s flu vaccine dosage?
Yes, there is a difference. Children (6 months – 8 years), who never had flu vaccine before, need to take 2 doses 4 weeks apart. Those younger than 3 years need to take half of the adult’s dose.
29. What is the recommended dose of the type of Influenza vaccines available in MOH Hospitals?
Two doses administered ≥1 month apart are recommended for children 8 years and younger who are receiving influenza vaccine for the first time.