Influenza (Flu) VaccineSummary ProductCharacteristicsName of the medicinal product:Influenza vaccine, suspensionfor injection (influenza vaccine, surface antigen inactivated).(Medicinesorguk, 2018)Composition of vaccine:The influenza vaccine for the2017/18 season, contains strains of haemagglutininand neuraminidase (surface antigensof the influenza virus) and protect against three types of flu virus:A/Michigan/45/2015 (H1N1)pdm09-likevirusA/Hong Kong/4801/2014H3N2-like virus B/Brisbane/60/2008-likevirus Vaccines are designed tocomply with the World Health Organization’s (WHO) recommendations. Strains offlu are identified each year, which are deemed to be the most likely cause ofthe current circulating flu virus. (Medicinesorguk, 2018)Pharmaceutical form:The vaccine has the appearanceof a clear liquid (as shown in Figure 1), and its suspension for injection ispresented in a pre-filled syringe.
TradeNames and Medicinal FormsIn the UK, there can bedifferences in the licensing of the same influenza vaccine as either asuspension for injection or as a spray. This is illustrated in the shown in thetables below: Supplier Name of product Vaccine form AstraZeneca UK Ltd FluMist Quadrivalent Nasal suspension 0.2ml unit dose AstraZeneca UK Ltd ? Fluenz Tetra Nasal suspension 0.2ml unit dose Supplier Name of product Vaccine form Non-proprietary Influenza vaccine (split virion, inactivated) Suspension for injection 0.
5ml pre-filled syringes Seqirus Ltd Agrippal Suspension for injection 0.5ml pre-filled syringes Pfizer Ltd Enzira Suspension for injection 0.5ml pre-filled syringes GlaxoSmithKline UK Ltd ? Fluarix Tetra Suspension for injection 0.
5ml pre-filled syringes BGP Products Ltd Imuvac Suspension for injection 0.5ml pre-filled syringes sanofi pasteur MSD Ltd Intanza – 15 microgram strain Suspension for injection 0.1ml pre-filled syringes BGP Products Ltd Influvac Sub-unit Suspension for injection 0.5ml pre-filled syringes Spray: Excipients may include: gelatine,gentamicinSuspension for injection: Excipients may include: gentamicin,kanamycin, neomycin penicillins, polymyxin b, thiomersal(Joint Formulary Committee., 2017)What is influenza?Influenzais an acute infection of the respiratory tract which is caused by a virus andaffects the respiratory system (consisting of the nose, throat, bronchi andlungs – see Figure 2). It is known to be very contagious and spreads easily viadroplets, aerosol in the environment or through the direct contact with therespiratory secretions of someone with the infection.
(Gov.uk, 2018)Flu can often be mistaken withthe likeness of the common cold. However, flu symptoms tend to be more severe andcan cause the onset of serious complications in vulnerable individuals (such aspneumonia, bronchitis, sinus and ear infections etc.
) if not treated as soon aspossible. Flu symptoms can appear suddenly, whereas colds develop gradually.(University of Maryland Medical Center,2018) What is the influenzavaccine used for and who can receive it?Antigens on the surface ofpathogens which enter the body, are detected by the body and help to prompt animmune response. This immune response involves the production of memory cellswhich remain in the body for a long time and recognise the specific antigen.So, if the virus enters the body again, the immune system can regulate aquicker response towards it.
However, influenza viruses are constantly altering their antigenic structures,forming new strains of the haemagglutinins and neuraminidases (see Figure 3). Thisis known as antigenic variation.Therefore, memory cells which were produced from the vaccination of one strain of the flu, will not recognisedifferent strains of the virus. As a result, flu vaccines are developed eachyear which contain the prevalent strains of haemagglutinins and neuraminidasesthat act most effectively to the recent circulating virus affecting the population. (Joint Formulary Committee., 2017)The NHS offers fluvaccinations every year in order to help protect adults and children at risk offlu and its effects, as well as tocontrol its spread across communities.
For healthy individuals the disease is usually self-limiting and recovery canoccur within a week (although they may experience unpleasant symptoms). But forcertain groups of people that are more at risk of developing more serious problemsof the flu, such as pneumonia, it is endorsed that they have the flu vaccineevery year to prevent this. Individuals eligible to receive a flu vaccinationunder the NHS include: Those of the age of 65or overPregnant womenAdults or children withchronic illnesses (such as long-term cardiac or respiratory diseases), or withweakened immune systems(Nhs.uk, 2018) PsychodynamicpropertiesSeroprotection(protection gained by vaccinating), is achieved within a few weeks of thevaccine being received.
The length of time in which postvaccinal immunityoccurs to the same strains or similar strains to the vaccine strain varies butit is usually between 6 to 12 months.(Medicinesorguk, 2018)Indication and Doses By intramuscular injection · Child (6 mths–17 yrs): 0.5?mL per dose · Adult: 0.5?mL per dose By intradermal injection · Adult (18–59 yrs): 9? ?g per dose, dose to be injected into deltoid region. · Adult (60 yrs and over): 15? ?g per dose, dose to be injected into deltoid region.
By intranasal administration · Child (2–17 yrs): 0.1?mL per dose, dose to be administered into each nostril. Indication: Annualimmunisation against seasonal influenzaTable 1 shows the doses for influenza vaccinations asaccording to the indication.
(Joint Formulary Committee., 2017)Routes of AdministrationMajority of vaccines areadministered via the intramuscular although some are delivered either deepsubcutaneously or by the intradermal route.Giving vaccinesintramuscularly should be avoided in patients with blood disorders, such as haemophiliaand should instead be given by deep subcutaneous injection.(Excellence, 2018)Vaccines for influenza shouldnot be administered intravascularly by any circumstances.(Medicinesorguk, 2018)How does theinfluenza vaccine bring about the restoration of immune homeostasis?When the inactive form of the influenza surface antigen isinjected through the skin, the first line of defences of the body becomespenetrated, resulting in the distortion of the body’s homeostatic balance.
Consequently, the immune system becomes activated to attack the “invadingagents” and return the body back to its normal state.The antigens of the foreign pathogens are detected andrecognised by the body. Next, the transmission of signals from cells such asphagocytes trigger the action of T-cells and B-cells. Both these lymphocyteshave specific receptors on their surfaces that are complementary to themolecular structures of different antigens. Once antigen-receptor complexesform, the mechanisms of these individual lymphocytes are induced to beginfighting the infectious agents.B-cells act by differentiating into plasma cells whichsecrete monoclonal antibodies that have a specific variable regioncomplimentary to the molecular structure of the antigen present in the vaccine.
This specificity is an important factor in aiding the body to fight theinfection by promoting further phagocytosis and also by controlling the spreadof microbes and pathogens in the future. Antibodies work effectively against microbes inextracellular locations of the body. T-cells, on the other hand, can workparticularly well by recognising intracellular infections such as the(influenza virus). Cytotoxic T-cells help to reduce the replication anddistribution of the virus killing bacterial cells or cells infected with thevirus. Helper T-cells work by secreting chemicals such as cytokines that signalother immune system cells and also cause inflammation in an attempt to containthe infection in one area of the body.The body produces memory cells against the strains of theantigens present in the vaccine.
This means that if the flu virus enters thebody again, the body will be able to mount a quicker immune response before anyof the symptoms are even experienced. This is known as a secondary immunesystem response which allows the body to remain protected from that particularstrain of the influenza virus and maintain immune homeostasis.(Study.com, 2018) (Bradley, Fry andHarris, n.
d.) FAQs for Patients”Whatif the flu vaccination causes the flu?”This is a common misunderstanding shared by many people.The influenza vaccine cannot cause flu as there are no active viruses in it.
Therefore, if you believe that you have flu after having taken the vaccine, itis possible that you’ve caught a flu-like virus that isn’t really flu or thatyou caught the flu before you had taken the vaccination and it is now takingeffect.”Whatare the side effects of getting vaccinated?”You may experience a mild fever, feel like you have achingmuscles and/or feel like the area where you received the injection feels sore afew days after getting vaccine. However, these symptoms tend to not last verylong and recovery usually takes place within a few days of taking the vaccine,without any necessary treatments. Severe allergic reactions, such as anaphylaxis are veryrare when given the flu vaccine. Nevertheless, the health care staff areprofessionally trained to deal with any side effects which are noticed and toprompt treatment as soon as possible.
“Howcan I deal with the side effects of the flu-jab?”If your arm feels sore after receiving the vaccine move itaround regularly so it doesn’t get stiff. You can try to use a heat pack orwarm compress and apply it to the affected area. If the arm begins to feel hotand sorer, try using an ice pack instead. Taking pain killers such asparacetamol and ibuprofen can help to overcome any of the mild symptoms. If your symptomsworsen or don’t improve over time contact a pharmacist or GP.
“Wherecan I get more information about whether or not I can take the fluvaccine?”You can contact your GP, doctor or pharmacist to get moreinformation about the flu vaccination and whether or not you can have itdepending on any medical conditions you may have. You can also find out if youare eligible to receive a vaccination under the NHS.