Influenza
The flu vaccine has stirred up a lot of confusion this year due to the upcoming release of a 'high dose/adjuvanted' flu vaccine later this month. The objective of this post is to answer some of the frequently asked questions in the community, in order to provide more clarity on the matter. Before we get into it, here are some quick general information about the influenza vaccine:
General Information
- The annual influenza vaccine is recommended for all persons above the age of 6 months as it helps to prevent influenza and its complications 1
- It takes about 2 weeks to kick in 2
- It is recommended in pregnancy, except the trivalent versions i.e. Fluzone High Dose & Fluad 1
- It can be safely administered to individuals with an allergy to eggs (including anaphylactic reaction to eggs: in a supervised setting) 5, 7
Frequently Asked Questions
What is the difference between the current vaccine that is available and the upcoming vaccine, which will be released later in the month of April?
The currently available flu vaccine has four strains (quadrivalent); whereas the upcoming vaccine will have three strains (trivalent) that has an added 'kick' to it to produce a better immune response. 1 The quadrivalent vaccine is recommended for the general community under the age of 65; while the trivalent vaccine was designed specifically for the waning immune system in the elderly (aged >65) to help elicit a greater immune response. 3, 6
How many brands of flu vaccines are available?
There will be five brands available for the quadrivalent vaccines and two brands for the trivalent vaccines.1
How many strains of virus does the vaccine protect you against?
The quadrivalent vaccines protects you against two A strains and two B strains. The trivalent version on the other hand protects you against two A strains and one B strain.1
I heard that children above the age of 6 months should be vaccinated but there are so many brands available on the market. Which is the most suitable brand for my child?
If your child is between the age of 3 years and 17 years old, they have the option of ‘Fluarix Tetra’ and ‘Flu Quadri.” However, if they’re between the age of 6 months and 35 months, they’ll be receiving ‘Flu Quadri Junior.”1
I heard that there will be two brands of the trivalent vaccines. What is the difference?
The first brand is called 'Fluzone High Dose Vaccine,' which essentially contains a more concentrated dose to help produce a stronger immune response. 6 The second brand Fluad, contains an adjuvant (i.e. a supplementary substance called squalene) to help produce a marked immunse response in the body. 3 Currently, there is no preference for use between either of the two brands. 1
My local pharmacist mentioned that the flu vaccine will provide optimal protection within the first 3 to 4 months following vaccination. So, should I get my shot now or later?
There are two arguments that can be made :
- The influenza virus can circulate all year round but the peak period is typically between June to September. 1 For this reason, you should ideally wait until the month of May to receive the vaccine, which will provide you with optimal coverage throughout the peak period of influenza ciculation.
- Although the vaccine offers optimal protection within the first 3-4 months following vaccination, 1 flu vaccines are designed to last all season long. 4 For this reason, it’s best to get your shot as soon as possible to ensure prompt protection.
There isn't a general consensus on the matter at the moment. Therefore, the best advise is to have each individual evaluated on a case to case basis by their healthcare provider to ensure that the most suitable decision is made regarding the timing of the vaccination.
Since the influenza vaccine only provides 3 to 4 months of optimal protection, can I receive the vaccination now and get revaccinated in a few months time?
Revaccination later in the same season for individuals who have already received vaccination is not recommended as there isn't any evidence to suggest additional protection; however it is not contraindicated 1, 6
My mum is above 65 years old. Can she receive the quadrivalent vaccine now and get the trivalent vaccine later when it is available?
The use of a quadrivalent and a trivalent (adjuvanted/high dose) vaccine has not been studied.1Hence, a statement on the matter can't be made at this point. In practice, a careful decision has to be made by your healthcare provider regarding your personal case.
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Resources
References
ATAGI. STATEMENT ON THE ADMINISTRATION OF SEASONAL INFLUENZA VACCINES IN 2018 [Internet]. ATAGI [updated 2018 Feb 19; cited 2018 Apr 1]. Available from: https://beta.health.gov.au/file/4791/download?token=ZeR_6YxK
CDC. Key Facts About Seasonal Flu Vaccine [Internet]. CDC [updated 2017 Oct 30; cited 2018 Apr 1]. Available from: https://www.cdc.gov/flu/protect/keyfacts.htm
Fluad. Clinical Overview of Fluad [Internet]. Fluad [updated 2016 Mar; cited 2018 Apr 1]. Available from: http://hcp.fluad.com/hcp/clinical-overview
Fluzone. Flu Shot Myths and Facts [Internet]. Fluzone [updated 2017 Aug 16; cited 2018 Apr 1]. Available from: http://www.fluzone.com/flu-facts.cfm
The Australian Immunisation Handbook. Influenza [Internet]. The Australian Immunisation Handbook [updated2017 Aug 1; cited 2018 Apr 2]. Available from: http://www.immunise.health.gov.au/internet/immunise/publishing.nsf/Content/Handbook10-home~handbook10part4~handbook10-4-7#4-7-10
Fluzone. Fluzone Vaccines [Internet]. Fluzone [updated 2017 Aug 16; cited 2018 Apr 1]. Available from: http://www.fluzone.com/fluzone-high-dose-vaccine.cfm
ASCIA. ASCIA Guidelines - Vaccination of the egg-allergic individual [Internet]. ASCIA [updated 2017 May; cited 2018 Apr 1]. Available from: https://www.allergy.org.au/health-professionals/papers/vaccination-of-the-egg-allergic-individual
Created by KW