Time to effect
About 10 – 14 days. Note that if someone in a high-risk group comes into contact with flu after the vaccine but before it’s likely to have taken effect, then they may be eligible for oseltamivir/zanamivir (check NICE guidelines).
Include fever, headache and malaise. These show up in a minority of patients and typically:
- Are mild
- Start 6 – 12 hours post-vaccine
- Settle after 1 – 2 days
All children of six months or older who are in clinical risk groups should be immunised. A programme to immunise all children from two to sixteen is being rolled out; as of this year, it has reached six-year-olds, so all children from age 2 to age 6 this winter should be immunised even if not in a risk group, and this should extend to progressively older upper age limits in coming years.
6 months ≤ children <2 years: inactivated trivalent influenza vaccine.
2 years ≤ children <18 years: Fluenz Tetra (live quadrivalent influenza vaccine, administered by nasal spray). If medically contraindicated, the second choice is Fluarix (TM) Tetra (inactivated quadrivalent vaccine) if the child is three or over, and inactivated trivalent vaccine for two-year-olds.
Children <9 years old who are receiving flu vaccine for the first time should receive a booster dose at least four weeks later. If the child would normally be having Fluenz Tetra but it is not available for the booster dose, an inactivated vaccine can be used instead.
Severe clinical immunodeficiency is a contraindication to Fluenz. HIV stable on antivirals is not a contraindication, nor are low-dose systemic corticosteroids, or steroids used as replacement therapy for adrenal insuffiency.
Systemic salicylate therapy in children and adolescents is currently considered a contraindication to the flu vaccine because of the association between Reye’s syndrome and flu-like illness.
Egg allergy is not a contraindication to Fluenz unless it consists of anaphylaxis severe enough to have necessitated ICU admission in the past, in which case Fluenz should be given in a hospital setting (see below).
Active wheezing/asthma attacks are temporary contraindications to Fluenz. It should not be given:
- During courses of oral steroids for respiratory disease or for 14 days later
- In children with active wheezing and/or increased use of bronchodilators during the previous 72 hours. However, note that if the respiratory symptoms in these children have not improved in a further 72 hours then they should be given an inactivated flu vaccine rather than delaying vaccination indefinitely, as they are clearly a high-risk group.
Children who are on high doses of inhaled steroids (>800 mcg/day Budesonide or >500 mcg/day Fluticasone) should only be given Fluenz on the advice of a specialist. However, if the advice is to refrain from giving Fluenz, then, like the children with active wheezing that isn’t improving, they should be given an inactivated vaccine instead due to their high risk status.
Fluenz Tetra (the version normally given to children) contains traces of egg, but has been found to be safe for egg-allergic children as long as the allergy isn’t severe enough to have required intensive care treatment. If it is, they should be referred to specialists for immunisation in hospital.
Adults with egg allergy can be safely given low-ovalbumin versions (<0.12 mcg/ml, which equates to <0.06 mcg in a 0.5 ml dose of vaccine) in any setting, unless, again, their allergy consists of anaphylaxis severe enough to require intensive care. In that case, they should be given Optaflu, an ovalbumin-free version that can be used on patients of 18 and over.
One study found a one-in-a-million increased risk of Guillain-Barré syndrome in people who had had the flu vaccination. Three other studies have not found the same risk. GBS is known to be associated with influenza-like illness, so being exposed to influenza may well be more of a risk.
The pneumococcal and influenza vaccinations can be given at the same time, but need to be given at different sites.
(NB – I made these notes from the BMJ module on immunisation, so the credit for that is included in my BMJ Learning portfolio. However, when I checked the reference for something in the module, I found it was actually out of date on one point regarding egg allergy, so as well as doing the module I had to check some of the key points with the Green Book. This took more than the allotted hour and so I am claiming an extra half credit over and above the credit for the BMJ module. Worth it for the up-to-date information!)