Vaccine recommendations for children and youth for the 2015/2016 influenza season

The Canadian Paediatric Society continues to encourage annual influenza vaccination for ALL children and youth ≥6 months of age. Recommendations from the National Advisory Committee on Immunization for the 2015/2016 influenza season include some important changes:

1. Children and adolescents with neurological or neurodevelopmental disorders were added to the list of individuals considered to be at high risk for severe influenza.
2. Quadrivalent influenza vaccines are recommended preferentially over trivalent vaccines for use in children and youth.
3. An adjuvanted trivalent inactivated influenza vaccine is now available for use in children six to 23 months of age.

     

Influenza vaccine recommendations for children and youth for the 2013/2014 season

Recommendations from the National Advisory Committee on Immunization concerning indications for the routine influenza vaccination of children and their close contacts have not changed from those of 2012/2013. Intranasal, live attenuated influenza vaccine (LAIV) is preferred over trivalent inactivated influenza vaccines (TIV) for healthy children and youth. There is insufficient evidence to recommend LAIV over TIV in children with chronic health conditions; either may be used unless there are specific contraindications. TIV may be used in persons with egg allergy; LAIV has not yet been evaluated in this population and is not recommended at this time.     

Safety and efficacy of trivalent inactivated influenza vaccine in young children: a summary for the new era of routine vaccination

Increasing use of influenza vaccine in children is expected as this important virus becomes more widely recognized as a major cause of morbidity in young children. Clinicians and third party payers must consider the implications of national vaccine use recommendations, with their current focus on young children, on their practices and on the community at large. Two influenza vaccines are available in the United States, an inactivated, trivalent intramuscular formulation (TIV) which is approved for use among children > or =6 months of age; and a live, attenuated intranasal trivalent preparation (LAIV) indicated for healthy persons 5 to 49 years of age. This review summarizes available data regarding the safety and efficacy of TIV, in comparison with LAIV, with particular attention to children <9 years of age, the population for whom two doses of vaccine are recommended for first time vaccination. It is apparent that relatively few data are available on the safety of TIV in young children, that important age-specific differences in TIV vaccine efficacy exist and that LAIV appears similar to TIV with regard to safety and efficacy in younger children, but no head-to-head comparison of these two licensed products is available.     

Parental acceptance of an intranasal vaccine: Example of influenza vaccine

Background

Influenza vaccination coverage of children with chronic disease is insufficient in France, although a nasal live attenuated influenza vaccine (LAIV) has been approved.

Influenza vaccination in India: Position paper of Indian Academy of Pediatrics, 2013

Burden of Influenza is significantly higher in developing countries as compared to developed countries, but the data on the disease burden is less well defined in most of the developing countries including India, and consequently, constraints evolving strategies for prioritization of measures to prevent and control it. The ‘swine flu’ or ‘A(H1N1)’ pandemic is on the wane but the virus continues to circulate causing sporadic outbreaks even in 2013. The A(H1N1)pdm09 has replaced the previous circulating seasonal A (H1N1) virus and acquired the status of a seasonal virus. Limited influenza activity is usually seen throughout the year in India with a clear peaking during the rainy season. The rainy season in the country lasts from June to August in all the regions except Tamil Nadu where it occurs from October to December. IAP recommends the ideal time for offering influenza vaccines is just before the onset of rainy season. The efficacy/effectiveness data of trivalent inactivated influenza vaccines are also presented in different age groups and different categories of individuals. The IAP maintains its earlier recommendations of using the current trivalent inactivated influenza vaccine in all children with risk factors but not as a universal measure. IAP has now prioritized different target groups for influenza vaccination based on contribution of the group to the overall influenza burden, disease severity, and vaccine effectiveness in different age groups and categories. The current trivalent inactivated influenza vaccines incorporate the 2009 pandemic strain also, hence avert the need of a separate ‘A (H1N1)’ vaccine. IAP stresses the need of more refined surveillance; large scale studies on effectiveness of seasonal influenza vaccines in Indian children, and more effective, properly matched, highervalent influenza vaccines.     

Comparison of the efficacy and safety of live attenuated cold-adapted influenza vaccine, trivalent, with trivalent inactivated influenza virus vaccine in children and adolescents with asthma

BACKGROUND: Despite their potential for increased morbidity, 75% to 90% of asthmatic children do not receive influenza vaccination. Live attenuated influenza vaccine (LAIV), a cold-adapted, temperature-sensitive, trivalent influenza vaccine, is approved for prevention of influenza in healthy children 5 to 19 years of age. LAIV has been studied in only a small number of children with asthma. METHODS: Children 6 to 17 years of age, with a clinical diagnosis of asthma, received a single dose of either intranasal CAIV-T (an investigational refrigerator-stable formulation of LAIV; n = 1114) or injectable trivalent inactivated influenza vaccine (TIV; n = 1115) in this randomized, open-label study during the 2002-2003 influenza season. Participants were followed up for culture-confirmed influenza illness, respiratory outcome, and safety. RESULTS: The incidence of community-acquired culture-confirmed influenza illness was 4.1% (CAIV-T) versus 6.2% (TIV), demonstrating a significantly greater relative efficacy of CAIV-T versus TIV of 34.7% (90% confidence interval [CI] 9.4%-53.2%; 95% CI = 3.9%-56.0%). There were no significant differences between treatment groups in the incidence of asthma exacerbations, mean peak expiratory flow rate findings, asthma symptom scores, or nighttime awakening scores. The incidence of runny nose/nasal congestion was higher for CAIV-T (66.2%) than TIV (52.5%) recipients. Approximately 70% of TIV recipients reported injection site reactions. CONCLUSIONS: CAIV-T was well tolerated in children and adolescents with asthma. There was no evidence of a significant increase in adverse pulmonary outcomes for CAIV-T compared with TIV. CAIV-T had a significantly greater relative efficacy of 35% compared with TIV in this high-risk population.     

Impfungen zum Schutz vor Atemwegsinfektionen bei Risikogruppen

Background

S. pneumoniae and influenza are the most common pathogens in the airways that are preventable by vaccination.

Objectives

The German Committee for Vaccinations (STIKO) also recommends vaccinations against pneumoccocci and influenza virus for subjects who are at risk. Using a literature search, we assessed which vaccines may be considered for which conditions.

Results

The STIKO gives an almost general recommendation for both pneumococcus and influenza vaccination. Children and adolescents with any condition considered a health risk may benefit from these immunisations. Namely, but not exclusively, patients with immunodeficiencies or airway diseases should be considered for vaccination. Pneumococcal conjugate vaccines appear more beneficial than the pneumococcal polysaccharide vaccine, also beyond the age of 5 years. A live attenuated influenza vaccine is more efficient than the trivalent inactivated influenza vaccine in children.

Conclusion

Vaccinations against pneumococci and influenza would greatly reduce morbidity caused by these pathogens in children and adolescents with chronic conditions.     

Increasing the use of influenza vaccines in children with egg allergy

Administration of inactivated trivalent or quadrivalent influenza vaccines is now believed to be safe for individuals with egg allergy. Unless children have experienced an anaphylactic reaction to a previous dose of influenza vaccine, they can and should be immunized with a full dose of trivalent or quadrivalent inactivated vaccine.     

Recommendations for influenza immunization of children

Epidemiologic studies indicate that children of all ages with certain chronic conditions and otherwise healthy children younger than 24 months of age are hospitalized for influenza infection and its complications at high rates similar to those experienced by the elderly. Annual influenza immunization is recommended for all children with high-risk conditions who are 6 months of age and older. Young, healthy children are at high risk of hospitalization for influenza infection; therefore, the American Academy of Pediatrics recommends influenza immunization for healthy children 6 through 24 months of age, for household contacts and out-of-home caregivers of all children younger than 24 months of age, and for health care professionals. To protect these children more fully against the complications of influenza, increased efforts are needed to identify all high-risk children and inform their parents when annual immunization is due. The purposes of this statement are to update recommendations for routine use of influenza vaccine in children and to review the indications for use of trivalent inactivated influenza vaccine and live-attenuated influenza vaccine.     

Measuring antibody responses to a live attenuated influenza vaccine in children

BACKGROUND: Hemagglutination inhibition (HAI) assay is the standard method for evaluating inactivated influenza vaccines, but no standard assay has been established for evaluating live attenuated influenza vaccines (LAIV). LAIV containing A/Beijing/262/95(H1N1) induced low serum HAI antibody responses to the antigenic variant, A/New Caledonia/20/99(H1N1) in a serologic study but provided protection against the A/New Caledonia-like viruses in a community study. Neutralization and HAI assays were compared by measuring H1N1 cross-reactive antibody responses to the LAIV in children. METHODS: Sera were collected from 50 children 1-8 years of age before vaccination and 4-6 weeks after each dose of the LAIV. Antibody titers to the 3 vaccine viruses were measured by the HAI assay, whereas antibody titers against the H1N1 vaccine virus (A/Beijing/262/95) and 2 H1N1 antigenic variants (A/Shenzhen/227/95 and A/New Caledonia/20/99) were measured by the HAI and neutralization assays. RESULTS: Initially seronegative participants were more likely to develop HAI seroconversion responses to the 3 vaccine viruses than the baseline seropositive participants (77% versus 14% for H1N1, 100% versus 20% for H3N2, 100% versus 19% for B, P < 0.01, Fisher's exact test). For the H1N1 cross-reactive antibody responses, seroconversion rates measured by the neutralization assay were significantly higher than those measured by the HAI assay (95% versus 78%, P = 0.0485 for A/Beijing/262/95; 75% versus 24%, P < 0.0001 for A/Shenzhen/227/95; 51% versus 5%, P < 0.0001 for A/New Caledonia/20/99). CONCLUSIONS: The neutralization assay was more sensitive than the HAI assay for measuring H1N1 antibody responses after vaccination of children with the LAIV and may provide a better correlate of clinical protection provided by the LAIV.     

Influenza vaccination among household contacts of children with cystic fibrosis and healthy children

BACKGROUND:

It is recommended that household contacts of children with cystic fibrosis and household contacts of children <2 years of age receive annual influenza vaccinations. There is little information documenting whether this recommendation is being followed.

METHODS:

A 20-question survey was distributed to caregivers of children with cystic fibrosis and to caregivers of healthy children <17 years of age seen in a Saskatoon (Saskatchewan) tertiary care centre. Survey questions addressed the influenza vaccination status of the child and household contacts. Respondents were also asked to rate the influence of various factors on the decision to vaccinate, using a 5-point Likert scale.

RESULTS:

Reported vaccination rates were 21%, 25% and 7% among household contacts of children with cystic fibrosis, children <2 years of age and children ≥2 years of age, respectively. Advice from their physician, belief that they were too healthy, and inconvenient times and locations of vaccination centres were significant influences when compared among the three groups. Other main deterrents to vaccination were belief that the vaccine does not prevent influenza and belief that its side effects are greater than its benefits.

CONCLUSION:

By understanding motivators and barriers to vaccination among household contacts of children with cystic fibrosis, effective strategies may be implemented to improve vaccination coverage against influenza. Strong recommendations by clinicians and improved access to vaccination centres are essential components in improving influenza vaccination coverage.     

Effectiveness and safety of inactivated influenza vaccination in pediatric liver transplant recipients over three influenza seasons

Annual influenza vaccination is recommended for pediatric liver transplant recipients, who are at high risk of influenza-related complications. However, effectiveness and safety of vaccination may differ among influenza seasons in this population and have not been fully evaluated. Subjects comprised 38 pediatric liver transplant recipients with or without influenza vaccination through the 2006-2007, 2007-2008 and 2008-2009 influenza seasons. Recipients received inactivated trivalent (AH1/AH3/B) influenza vaccine, and comparisons were made to non-vaccinated recipients with regard to effectiveness and safety. No significant differences were seen between recipient groups for acute allograft rejection, acute febrile illness, or influenza virus infection. No serious systemic adverse events were observed in vaccinated recipients. Seroprotection rate (defined as the proportion of recipients with HI antibody titer ≥ 1:40), seroconversion rate (proportion of recipients with a ≥ 4-fold increase in HI titers), and geometric mean titers were mostly elevated after vaccination for the three influenza antigens in each season. These three indicators of immunogenicity showed similar results in both vaccinated recipients and vaccinated healthy children in the 2007-2008 season. These findings suggest that pediatric liver transplant patients may respond safely to inactivated seasonal influenza vaccines in a similar manner to healthy children, and effectiveness varies among influenza seasons.     

The use of inactivated influenza vaccine in children

The impact of influenza in the very young appears to be comparable to that in the elderly. Influenza vaccine strategy is changing to reflect that impact. Currently, the broader recommendations include vaccination with trivalent inactivated influenza vaccines (TIVs) for children aged 6 to 59 months. This article reviews TIV safety, immunogenicity, and efficacy in children, current vaccine recommendations, and vaccine administration and dosage.     

Live attenuated and inactivated influenza vaccine in school-age children

In 1985, we enrolled 189 school-age children by family in a double-blind study to determine protection against influenza by a single dose of cold-recombinant bivalent A vaccine or commercial trivalent inactivated vaccine compared with placebo. All children in school or day care, 3 to 18 years of age, in an enrolled family received the same preparation. Following vaccination, 60% and 21% of cold-recombinant bivalent A vaccine recipients and 73% and 83% of trivalent inactivated vaccine recipients demonstrated fourfold or greater response in hemagglutination-inhibition antibody titer to A/H1N1 and A/H3N2, respectively. Sixty-seven percent of all trivalent inactivated vaccine recipients demonstrated a fourfold or greater serologic response to H1N1, H3N2, and influenza B following a single dose of vaccine. During the 1985-1986 influenza B/Ann Arbor epidemic, heterotypic protection afforded by the influenza B/USSR component of trivalent inactivated vaccine was 62% compared with placebo. A single dose of trivalent inactivated vaccine protected school-age children, 6 to 19 years of age, from influenza B infection; the rate of protection was 64% against infection and 73% against febrile illness.     

Live attenuated influenza vaccine in children

Live attenuated influenza vaccine (LAIV) offers a novel approach to influenza vaccination and is approved for healthy individuals 5 to 49 years of age. In placebo-controlled studies in children, LAIV was 73 to 93 percent efficacious, and protection lasted more than 12 months. In head-to-head studies in children, LAIV demonstrated a 35 to 53 percent reduction in influenza attack rates compared with injectable influenza vaccine (TIV) for matched strains. Compared with TIV, LAIV has demonstrated broader serum antibody responses, particularly against mismatched influenza A. The most common adverse events are runny nose and nasal congestion. Increased rates of asthma events were observed in young children. Additional large-scale safety and efficacy studies in young children, including a formal risk-benefit assessment, are ongoing. The results of these analyses will guide potential future use in young children.     

Recommendations for prevention and control of influenza in children, 2011-2012

The purpose of this statement is to update recommendations for routine use of trivalent seasonal influenza vaccine and antiviral medications for the prevention and treatment of influenza in children. The key points for the upcoming 2011-2012 season are that (1) the influenza vaccine composition for the 2011-2012 season is unchanged from the 2010-2011 season, (2) annual universal influenza immunization is indicated, (3) a simplified dosing algorithm for administration of influenza vaccine to children 6 months through 8 years of age has been created, (4) most children presumed to have egg allergy can safely receive influenza vaccine in the office without need for an allergy consultation, and (5) an intradermal trivalent inactivated influenza vaccine has been licensed for the 2011-2012 season for use in people 18 through 64 years of age. Pediatricians, nurses, and all health care personnel have leadership roles in the prevention of influenza through vaccine use and public education. In addition, pediatricians should promptly identify influenza infections to enable rapid treatment, when indicated, to reduce childhood morbidity and mortality.     

Use of influenza vaccines in children with an egg allergy

Children are at increased risk of morbidity from influenza. Influenza vaccines are grown in eggs, leading to a minute amount of egg protein in their composition. Recent research and new practice parameters spurred by the 2009 global influenza pandemic have challenged the need to withhold influenza vaccine from patients with an egg allergy. The available data suggest that anaphylaxis from influenza vaccines is exceptionally rare, even in patients with an egg allergy. Reported allergic reactions to trivalent inactivated influenza vaccine and pH1N1 influenza vaccines have been rare; when reactions occurred, they have not caused anaphylaxis. This position statement reviews the available evidence on influenza vaccine/egg allergy-related anaphylaxis, and recommends protocols to safely administer the trivalent inactivated influenza vaccine in lower- and higher-risk children with an egg allergy.     

Rationale and approach to target children with asthma for annual influenza immunization

Influenza virus infection can cause an acute exacerbation of asthma that may result in hospitalization. Annual influenza vaccination is recommended for children with asthma, but fewer than 10 percent receive it. This review summarizes the influenza-associated morbidity in children with asthma. The risk-versus-benefit of influenza vaccination in children with asthma is evaluated. Strategies to improve influenza vaccine uptake in children with asthma are investigated. Influenza virus infection causes substantial morbidity in children with asthma. Data on safety and effectiveness of the trivalent influenza vaccine in these children are limited. However, it is generally safe and effective in preventing influenza infection. The investigational live-attenuated, cold-adapted, trivalent nasal spray influenza vaccine needs evaluation for safety and efficacy in children with asthma. An annual, well-organized, computerized multicomponent strategy should be implemented for optimizing influenza immunization in the high-risk population. Children with asthma should be targeted for annual influenza immunization.     

Grippeschutzimpfung bei Kindern

In 19 children of 1–7 years of age hemagglutination inhibiting antibodies were measured before and after vaccination against influenza. Before vaccination the serum titers have been markedly lower than in adults. A single vaccination with Alorbat^®, a vaccine of representative strains of influenza virus inactivated and adsorbed to aluminumoxide, was followed by the same rise of titer as in adults. Therefore with this vaccine a single vaccination is effective in children, and a booster 4 weeks later, as recommended otherwise, is not necessary.