Summary of the safety profile
Safety data regarding use of Fluenz are based on data from Fluenz clinical studies in over 29 000 children and adolescents 2 to 17 years of age, Fluenz post‑authorisation safety studies in over 84 000 children and adolescents 2 to 17 years of age, and data from influenza vaccine (live attenuated, nasal) tetravalent clinical studies in over 2 000 children and adolescents 2 to 17 years of age. Additional experience has occurred with marketed use of Fluenz and /or influenza vaccine (live attenuated, nasal) tetravalent.
In clinical studies, the safety profile of Fluenz and influenza vaccine (live attenuated, nasal tetravalent were similar.
The most common adverse reaction observed in clinical studies was nasal congestion/rhinorrhoea.
Tabulated list of adverse reactions
Adverse reaction frequencies are organised by MedDRA System Organ Class (SOC). Within each SOC, adverse reactions are arranged by decreasing frequency and then by decreasing seriousness. Frequencies of occurance of adverse reactions are defined as:
very common (≥1/10);
common (≥1/100 to <1/10);
uncommon (≥1/1 000 to <1/100);
rare (≥1/10 000 to <1/1 000);
very rare (<1/10 000) and not known (cannot be estimated from available data).
Table 1 Adverse reactions
| MedDRA SOC | Adverse reaction | Frequency |
| Immune system disorders | Hypersensitivity reactions (including facial oedema, urticaria) | Uncommon |
| Anaphylactic reactions | Very rare |
| Metabolism and nutrition disorders | Decreased appetite | Very common |
| Nervous system disorders | Headache | Common |
| Guillain‑Barré syndrome | Not knowna |
| Respiratory, thoracic and mediastinal disorders | Nasal congestion/rhinorrhoea | Very common |
| Epistaxis | Uncommon |
| Skin and subcutaneous tissue disorders | Rash | Uncommon |
| Musculoskeletal and connective tissue disorders | Myalgia | Common |
| General disorders and administration site conditions | Malaise | Very common |
| Pyrexia | Common |
| Congenital, familial, and genetic disorders | Exacerbation of symptoms of Leigh syndrome (mitochondrial encephalomyopathy) | Not knowna |
a Post‑marketing experience
Paediatric population
In an active‑controlled clinical study (MI‑CP111), an increased rate of hospitalisations (for any cause) through 180 days after final vaccination dose was observed in infants and toddlers 6‑11 months of age (6.1% Fluenz versus 2.6% injectable influenza vaccine). Most hospitalisations were due to gastrointestinal and respiratory tract infections and occurred more than 6 weeks post vaccination. The rate of hospitalisations was not increased in Fluenz recipients 12 months and older. In the same study, an increased rate of wheezing through 42 days was observed in infants and toddlers 6‑23 months of age (5.9% Fluenz versus 3.8% injectable influenza vaccine). The rate of wheezing was not increased in Fluenz recipients 2 years and older. Fluenz is not indicated for use in infants and toddlers younger than 2 years (see section 4.2).
Concurrent illness and chronic conditions
In a study (D153‑P515) of children 6 to 17 years of age with asthma (Fluenz: n=1 114, trivalent injectable influenza vaccine: n=1 115), there were no significant differences between treatment groups in the incidence of asthma exacerbations, mean peak expiratory flow rate, asthma symptom scores, or night‑time awakening scores. The incidence of wheezing within 15 days after vaccination was lower in Fluenz recipients relative to inactivated vaccine recipients (19.5% vs. 23.8%, P=0.02).
In a study of children and adolescents 9 to 17 years of age with moderate to severe asthma (Fluenz: n=24, placebo: n=24), the primary safety criterion, change in percent predicted forced expiratory volume in 1 second (FEV1) measured before and after vaccination, did not differ between treatment arms.
Although safety in children and adolescents with mild to moderate asthma has been established, data in children with other pulmonary diseases or with chronic cardiovascular, metabolic or renal diseases, or other underlying chronic medical conditions are limited. In a study of adults 60 years of age and older (n=3 242), a high percentage of individuals had underlying chronic medical conditions (87%), including cardiac disorders (15%), respiratory, thoracic and mediastinal disorders (13%), and diabetes mellitus (9.6%). The safety profile of Fluenz in these individuals was comparable to the safety profile observed in individuals without these conditions.
Immunocompromised individuals
In HIV‑infected children (n=24) and HIV‑negative children (n=25) 1 through 7 years of age, and in HIV‑infected children and adolescents 5 through 17 years of age receiving stable anti‑retroviral therapy (Fluenz: n=122, trivalent injectable vaccine: n=121), the frequency and duration of vaccine virus shedding were comparable to that seen in healthy individuals. No adverse effects on HIV viral load or CD4 counts were identified following Fluenz administration.
Twenty mild to moderately immunocompromised children and adolescents 5 through 17 years of age (receiving chemotherapy and/or radiation therapy or who had recently received chemotherapy) were randomised 1:1 to Fluenz or placebo. Frequency and duration of vaccine virus shedding in these immunocompromised children and adolescents were comparable to that seen in healthy children and adolescents.
Reporting of suspected adverse reactions
Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme at www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store.