Adverse Events Following Immunisation (AEFI) Noel McCarthy Thames Valley Public Health England Centre and Everybody

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1 Adverse Events Following Immunisation (AEFI) Noel McCarthy Thames Valley Public Health England Centre and Everybody

2 A fifteen year old with diabetes came for his MMR and was referred by the school nurse to your surgery because he had egg allergy. Should he have the vaccine? How will you proceed? Should he have flu vaccine annually?

3 What is anaphylaxis? Definition of anaphylaxis Typically rapid and unpredictable with variable severity and clinical features including cardiovascular collapse, bronchospasm, angioedema, pulmonary oedema, loss of consciousness and urticaria Potentially life threatening Adverse Event Following Immunisation (AEFI) One of four types of hypersensitivity reactions Very rare per million immunisations (Bohlke et al. Risk of Anaphylaxis After Vaccination of Children and Adolescents Pediatrics 2003; 112: )

4 Potential triggers to anaphylaxis Various common allergens (Nuts, shellfish, dairy products. Wasp or bee stings, latex, antibiotics etc) Vaccine specific Egg proteins (yellow fever and influenza vaccines) Thiomersal (some flu and hep B vaccines) Antibiotics (Neomycin, gentamicin, streptomycin and polymixin B) Stabilisers and other vaccine components (Yeast, gelatin) Toxoid (DTaP, Td)

5 Signs and symptoms of anaphylaxis System Symptoms Respiratory Tract Cardiovascular System Gastrointestinal System Skin Rhinitis-sneezing, nasal itching Laryngeal oedema- Stridor Bronchospasm- cough, wheeze Respiratory arrest. Tachycardia, Hypotension arrhythmias, cardiac arrest Nausea, vomiting, abdominal pain, diarrhoea Sweating, flushing, Urticaria, periorbital oedema Central Nervous system Anxiety, convulsions, loss of consciousness, sense of impending doom

6 Distinguishing anaphylaxis from other common reactions to vaccination. Syncope (Faint) Anxiety attack Breath holding episode Anaphylaxis Good central pulses but may be bradycardic Respiration continues Pallor Warm skin Unusual in preschool children No upper airway oedema No itching Patient regains consciousness when lying down May appear fearful Usually tachycardic Hyperventilation Pallor Complain of tingling of face and extremities Complain of feeling lightheaded, dizzy or numb Mainly in young children Generally distressed/ crying prior to episode Facial flushing and perioral cynosis Can briefly become unconscious during which breathing returns Poor central pulses, usually sinus tachycardia Possible apnoea, especially in children Upper airway oedema, sneezing Bronchospasm, may be audible expiratory wheeze or stridor Urticarial lesions Itching Sense of impending doom Flushing/sweating Cold skin Patient does not revive when lying down

7 Management of anaphylaxis - standard - effective Resuscitation Council (UK)

8 A patient 65 year old with flu-like illness asks if maybe he missed protection because some vaccine spilled when he came in for their first ever pneumococcal and flu vaccines this year. What do you need to do / check?

9 A patient 65 year old with flu-like illness asks if maybe he missed protection because some vaccine spilled when he came in for their first ever pneumococcal and flu vaccines this year. What do you need to do / check? If not repeated what do you do?

10 A patient 65 year old with flu-like illness asks if maybe he missed protection because some vaccine spilled when he came in for their first ever pneumococcal and flu vaccines this year. What do you need to do / check? If not repeated what do you do? If you can t find out which what do you do? Anything else to do?

11 Adverse events following immunisation Due to vaccine Delivery programme / clinical error

12 Swollen arm and a lump at the site of injection (Pandemrix flu vaccine) Patient asks Why? Should she avoid flu vaccine in case this recurs What should you advise? How common would you tell her this reaction is? Is she at particular risk of it recurring? Anything else?

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14 How safe are our vaccines? How do we know that they are very safe?

15 Vaccine trials Initial safety trials (Phase 1, healthy adults, n ~10) Phase 2 safety, estimate dose, check effects Phase 3 Clinical trials (treatment and placebo) Show individual protection Show no frequent serious adverse effects Trial size (hundreds to thousands) Outcomes Protection against infection Surrogate e.g. antibody levels

16 Post licensure studies Vaccine effectiveness Adverse events (phase 4 surveillance) Larger number of people vaccinated Diverse range of people vaccinated Manufacturing problems etc

17 How safe are our vaccines? How do we know that they are very safe?

18 How safe are our vaccines? How do we know that they are very safe? Because we report possible adverse events

19 Types of adverse event (due to vaccines) Local Reactions Especially common with non-live vaccines containing adjuvants (Pain, redness, swelling at injection site) Systemic Reactions Generally more common following live vaccine, but less severe with subsequent doses (Fever, headache, loss of appetite) Allergic Reaction Anaphylaxis/Severe systemic allergic reaction

20 Vaccine-induced AEFI Classification of Adverse Events Following Immunisation (AEFI) Intrinsic to the vaccine and patient Programmatic errors Incorrect doses or routes, wrong diluent Coincidental events Chance happening Injection reaction (immediate) Result of injection itself, not the vaccine Unknown Cause cannot be determined

21 A group of patients who got flu from last years flu vaccine How would you advise them? Can you guarantee them that they will not get flu this year if they have it? Report it?

22 Thanks you Questions? 22 PHE Update for Berkshire PH 18/4/13