Efficacy of a Cell-Culture-Derived Quadrivalent Influenza Vaccine in Children.

BACKGROUND: Cell-culture-derived influenza vaccines may enable a closer antigenic match to circulating strains of influenza virus by avoiding egg-adapted mutations. METHODS: We evaluated the efficacy of a cell-culture-derived quadrivalent inactivated influenza vaccine (IIV4c) using a Madin-Darby canine kidney cell line in children and adolescents 2 to less than 18 years of age. During three influenza seasons, participants from eight countries were enrolled in an observer-blinded, randomized clinical trial comparing IIV4c with a noninfluenza vaccine (meningococcal ACWY). All the participants received a dose of a trial vaccine. Children 2 to less than 9 years of age without previous influenza vaccination who were assigned to the IIV4c group received a second dose on day 29; their counterparts who were assigned to the comparator group received placebo. Participants were followed for at least 180 days for efficacy and safety. The presence of influenza virus in nasopharyngeal swabs from participants with influenza-like illness was confirmed by reverse-transcriptase-polymerase-chain-reaction assay and viral culture. A Cox proportional-hazards model was used to evaluate the efficacy of IIV4c as measured by the first occurrence of laboratory-confirmed type A or B influenza (primary end point). RESULTS: Between 2017 and 2019, a total of 4514 participants were randomly assigned to receive IIV4c or the meningococcal ACWY vaccine. Laboratory-confirmed influenza occurred in 175 of 2257 participants (7.8%) in the IIV4c group and in 364 of 2252 participants (16.2%) in the comparator group, and the efficacy of IIV4c was 54.6% (95% confidence interval [CI], 45.7 to 62.1). Efficacy was 80.7% (95% CI, 69.2 to 87.9) against influenza A/H1N1, 42.1% (95% CI, 20.3 to 57.9) against influenza A/H3N2, and 47.6% (95% CI, 31.4 to 60.0) against influenza B. IIV4c showed consistent vaccine efficacy in subgroups according to age, sex, race, and previous influenza vaccination. The incidences of adverse events were similar in the IIV4c group and the comparator group. CONCLUSIONS: IIV4c provided protection against influenza in healthy children and adolescents across seasons, regardless of previous influenza vaccination. (Funded by Seqirus; EudraCT number, 2016-002883-15; ClinicalTrials.gov number, NCT03165617.).

Pneumococcal conjugate vaccines for preventing acute otitis media in children.

BACKGROUND: Prior to introducing pneumococcal conjugate vaccines (PCVs), Streptococcus pneumoniae was most commonly isolated from middle ear fluid of children with acute otitis media (AOM). Reducing nasopharyngeal colonisation of this bacterium by PCVs may lead to a decline in AOM. The effects of PCVs deserve ongoing monitoring since studies from the post-PCV era report a shift in causative otopathogens towards non-vaccine serotypes and other bacteria. This updated Cochrane Review was first published in 2002 and updated in 2004, 2009, and 2014. The review title was changed (to include the population, i.e. children) for this update. OBJECTIVES: To assess the effect of PCVs in preventing AOM in children up to 12 years of age. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, CINAHL, LILACS, Web of Science, and trials registers (ClinicalTrials.gov and WHO ICTRP) to 29 March 2019. SELECTION CRITERIA: Randomised controlled trials of PCV versus placebo or control vaccine. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. The primary outcomes were frequency of all-cause AOM and adverse effects. Secondary outcomes included frequency of pneumococcal AOM and frequency of recurrent AOM (defined as three or more AOM episodes in six months or four or more in one year). We used GRADE to assess the quality of the evidence. MAIN RESULTS: We included 14 publications of 11 trials (60,733 children, range 74 to 37,868 per trial) of 7- to 11-valent PCVs versus control vaccines (meningococcus type C vaccine in three trials, and hepatitis A or B vaccine in eight trials). We included two additional trials for this update. We did not find any relevant trials with the newer 13-valent PCV. Most studies were funded by pharmaceutical companies. Overall, risk of bias was low. In seven trials (59,415 children) PCVs were administered in early infancy, while four trials (1318 children) included children aged one year and over who were either healthy or had a history of respiratory illness. There was considerable clinical heterogeneity across studies, therefore we did not perform meta-analyses.Adverse eventsNine trials reported on adverse effects (77,389 children; high-quality evidence). Mild local reactions and fever were common in both groups, and occurred more frequently in PCV than in control vaccine groups: redness (< 2.5 cm): 5% to 20% versus 0% to 16%; swelling (< 2.5 cm): 5% to 12% versus 0% to 8%; and fever (< 39 °C): 15% to 44% versus 8% to 25%. More severe redness (> 2.5 cm), swelling (> 2.5 cm), and fever (> 39 °C) occurred less frequently (0% to 0.9%, 0.1% to 1.3%, and 0.4% to 2.5%, respectively in children receiving PCV) and did not differ significantly between PCV and control vaccine groups. Pain or tenderness, or both was reported more frequently in PCV than in control vaccine groups: 3% to 38% versus 0% to 8%. Serious adverse events judged causally related to vaccination were rare and did not differ significantly between groups, and no fatal serious adverse event judged causally related to vaccination was reported.PCV administered in early infancyPCV7The effect of a licenced 7-valent PCV with CRM197 as carrier protein (CRM197-PCV7) on all-cause AOM varied from -5% (95% confidence interval (CI) -25% to 12%) relative risk reduction (RRR) in high-risk infants (1 trial; 944 children; moderate-quality evidence) to 6% (95% CI -4% to 16%; 1 trial; 1662 children) and 6% (95% CI 4% to 9%; 1 trial; 37,868 children) RRR in low-risk infants (high-quality evidence). PCV7 with the outer membrane protein complex of Neisseria meningitidis serogroup B as carrier protein (OMPC-PCV7), was not associated with a reduction in all-cause AOM (RRR -1%, 95% CI -12% to 10%; 1 trial; 1666 children; high-quality evidence).CRM197-PCV7 and OMPC-PCV7 were associated with 20% (95% CI 7% to 31%) and 25% (95% CI 11% to 37%) RRR in pneumococcal AOM, respectively (2 trials; 3328 children; high-quality evidence) and CRM197-PCV7 with 9% (95% CI -12% to 27%) to 10% (95% CI 7% to 13%) RRR in recurrent AOM (2 trials; 39,530 children; high-quality evidence).PHiD-CV10/11The effect of a licenced 10-valent PCV conjugated to protein D, a surface lipoprotein of Haemophilus influenzae, (PHiD-CV10) on all-cause AOM varied from 6% (95% CI -6% to 17%; 1 trial; 5095 children) to 15% (95% CI -1% to 28%; 1 trial; 7359 children) RRR in healthy infants (moderate-quality evidence). PHiD-CV11 was associated with 34% (95% CI 21% to 44%) RRR in all-cause AOM (1 trial; 4968 children; high-quality evidence).PHiD-CV10 and PHiD-CV11 were associated with 53% (95% CI 16% to 74%) and 52% (95% CI 37% to 63%) RRR in pneumococcal AOM (2 trials; 12,327 children; high-quality evidence) and PHiD-CV11 with 56% (95% CI -2% to 80%) RRR in recurrent AOM (1 trial; 4968 children; moderate-quality evidence).PCV administered at later agePCV7We found no evidence of a beneficial effect on all-cause AOM of administering CRM197-PCV7 in children aged 1 to 7 years with a history of respiratory illness or frequent AOM (2 trials; 457 children; high-quality evidence) and CRM197-PCV7 combined with a trivalent influenza vaccine in children aged 18 to 72 months with a history of respiratory tract infections (1 trial; 597 children; high-quality evidence).CRM197-PCV9In 1 trial including 264 healthy day-care attendees aged 1 to 3 years, CRM197-PCV9 was associated with 17% (95% CI -2% to 33%) RRR in parent-reported all-cause OM (low-quality evidence). AUTHORS' CONCLUSIONS: Administration of the licenced CRM197-PCV7 and PHiD-CV10 during early infancy is associated with large relative risk reductions in pneumococcal AOM. However, the effects of these vaccines on all-cause AOM is far more uncertain. We found no evidence of a beneficial effect on all-cause AOM of administering PCVs in high-risk infants, after early infancy (i.e. in children one year and above), and in older children with a history of respiratory illness. Compared to control vaccines, PCVs were associated with an increase in mild local reactions (redness, swelling), fever, and pain and/or tenderness. We found no evidence of a difference in more severe local reactions, fever, or serious adverse events judged causally related to vaccination.

Does pneumococcal conjugate vaccination affect onset and risk of first acute otitis media and recurrences? A primary care-based cohort study.

BACKGROUND: It has been hypothesized that widespread implementation of pneumococcal conjugate vaccination (PCV) in infancy reduces early AOM and thereby prevents further AOM episodes and associated health care resource use. METHODS: We tested this hypothesis by applying an extension of the original Cox proportional hazards model (Prentice, Williams and Petersons' total time) to individual AOM episodes recorded in pseudonymised primary care electronic health records of 18,237 Dutch children born between 2004 and 2015. Children were assigned to three groups: no-PCV (January 2004-March 2006), PCV7 (April 2006-February 2011) and PCV10 (March 2011-February 2015). RESULTS: Of the 18,237 newborns, 6967 (38%) experienced at least one GP-diagnosed AOM episode up to the age of four years (median age at first AOM: 12 months, interquartile range: 12; total number of AOM episodes: 14,689). Time-to-first AOM was longest in the PCV10 group compared with the PCV7 and no-PCV groups (log rank test: P < 0.001); in these groups 30% had experienced a first AOM at 20, 17 and 15 months, respectively. Children in the PCV10 group had a 21% lower risk of experiencing a first AOM episode than those in the no-PCV group (hazard ratio (HR): 0.79, 95% confidence interval (CI): 0.72-0.86), while the effect was less pronounced for the PCV7 group (HR: 0.94, 95% CI: 0.87-1.02). Neither PCV7 nor PCV10 reduced the risk of AOM recurrences. Compared to no-PCV, HRs for overall AOM were 1.00 (95% CI: 0.95-1.06) and 0.89 (95% CI: 0.84-0.95) for PCV7 and PCV10, respectively. CONCLUSION: Our cohort study suggests that PCV postpones the onset and reduces the risk of first AOM without affecting recurrences. The impact of PCV on overall AOM in children up to the age of four years seems therefore largely attributable to the prevention of a first AOM episode.

Increasing FIM2/3 antigen-content improves efficacy of Bordetella pertussis vaccines in mice in vivo without altering vaccine-induced human reactogenicity biomarkers in vitro.

Current acellular-pertussis (aP) vaccines appear inadequate for long-term pertussis control because of short-lived efficacy and the increasing prevalence of pertactin-negative isolates which may negatively impact vaccine efficacy. In this study, we added fimbriae (FIM)2 and FIM3 protein to licensed 2-, 3- or 5-component aP vaccines (Pentavac®, Boostrix®, Adacel®, respectively) to assess whether an aP vaccine with enhanced FIM content demonstrates enhanced efficacy. Vaccine-induced protection was assessed in an intranasal mouse challenge model. In addition, potential reactogenicity was measured by biomarkers in a human whole blood assay (WBA) in vitro and benchmarked the responses against licensed whole cell pertussis (wP) and aP vaccines including Easyfive®, Pentavac® and Pentacel®. The results show that commercial vaccines demonstrated reduced efficacy against pertactin-negative versus pertactin-positive strains. However, addition of higher amounts of FIM2/3 to aP vaccines reduced lung colonization and increased vaccine efficacy against a pertactin-negative strain in a dose-dependent manner. Improvements in efficacy were similar for FIM2 and FIM3-expressing strains. Increasing the amount of FIM2/3 proteins in aP formulations did not alter vaccine-induced biomarkers of potential reactogenicity including prostaglandin E2, cytokines and chemokines in human newborn cord and adult peripheral blood tested in vitro. These results suggest that increasing the quantity of FIM proteins in current pertussis vaccine formulations may further enhance vaccine efficacy against B. pertussis infection without increasing the reactogenicity of the vaccine.

Outpatient antibiotic use in Dutch infants after 10-valent pneumococcal vaccine introduction: a time-series analysis.

OBJECTIVE: This population-based cohort study assesses the impact of switching from a 7-valent pneumococcal conjugate vaccine (PCV) to a 10-valent PCV on outpatient antibiotic use in Dutch infants, and whether geographical vaccination coverage modifies this association. SETTING AND PARTICIPANTS: We extracted 2006-2013 anonymised antibiotic purchase data of 255 154 Dutch infants aged below 2 years from Achmea Health, a health insurance fund covering 28% of the national population. DESIGN AND MAIN OUTCOME MEASURE: Changes in monthly antibiotic use from 2006-2011 (PCV7) to 2011-2013 (PCV10) were estimated using time-series analysis accounting for seasonality and autocorrelation. Interaction terms for vaccination coverage (categorised into seven groups) and period were added to the model to test whether this association was vaccination coverage-dependent. RESULTS: 275 337 antibiotic courses were used by 119 078 infants (461 352 person-years). PCV10 introduction was associated with a modest 1.6% overall reduction in antibiotic use (purchase rate ratio: 0.98, 95% CI: 0.98 to 0.99). Our model showed a significant difference in time trend in antibiotic use after PCV10 introduction (p=0.0084) with an increase in prescriptions in the PCV7 period (slope: 0.0023/month, 95% CI: -0.0001 to 0.0047) versus a decline in the PCV10 period (slope: -0.0089/month, 95% CI: -0.0150 to -0.0029). There was no evidence that PCV vaccination coverage affected this association, but since the largest rate ratios were observed in municipalities with the lowest vaccine coverage and had very wide accompanying CIs, our study might have insufficient power to detect such an association. CONCLUSIONS: Switching from PCV7 to PCV10 was associated with a modest decline in outpatient antibiotic use in Dutch infants.

Impact of Early-Onset Acute Otitis Media on Multiple Recurrences and Associated Health Care Use.

OBJECTIVE: To quantify the critical age period of first episode of acute otitis media (AOM) and its consequences for AOM recurrences and AOM health care use. STUDY DESIGN: Children enrolled in the Wheezing-Illnesses-STudy-LEidsche-Rijn cohort with at least 1 episode of AOM documented in their primary care health record before 2 years of age were followed until 6 years of age. Data on episodes of AOM and associated primary care consultations, antibiotic prescriptions, and specialist referrals were retrieved. Regression models assessed the presence and shape of the associations between age of first AOM and subsequent episodes of AOM and health care use. RESULTS: A total of 796 of 2026 children (39%) experienced a first AOM before 2 years of age. Each month decrease in age at first AOM in the first 2 years of life increased the risk of developing recurrent AOM (≥3 AOM episodes in 6 months or ≥ 4 in 1 year) linearly by 6% (adjusted risk ratio: 1.06; 95% CI: 1.02-1.10). For first AOM occurring before 9 months, the cumulative 6-year primary care consultation rate increased by 8% (adjusted incidence rate ratio: 1.08; 95% CI: 1.03-1.15) and the associated specialist referral increased by 16% (adjusted risk ratio: 1.16; 95% CI: 1.07-1.27) for each month decrease in age. No associations were found between age at first AOM and total AOM episodes or antibiotic prescriptions. CONCLUSIONS: The association between earlier age of first AOM and recurrent AOM as well as total health care use during childhood is particularly strong before 9 months of age.

Parent-reported symptoms of acute otitis media during the first year of life: what is beneath the surface?

BACKGROUND: Most estimates of the incidence of acute otitis media (AOM) are based on general practitioner (GP) or pediatrician diagnoses. It is likely that these figures underestimate the community incidence of AOM since parents do not visit their doctor every time their child suffers from acute ear symptoms. The impact of these symptom episodes may be substantial since they affect the child's quality of life and parents' productivity. METHODS: To determine AOM symptoms in the community, we measured parent-reported AOM symptoms daily for 12 consecutive months in 1,260 children participating in a prospective birth cohort in the Netherlands. The mean age of these children was at study enrollment 0.9 months (standard deviation 0.6). A parent-reported AOM symptom episode was defined as fever (temperature 38˚C or above) plus at least one of the following symptoms: ear pain and ear discharge. These febrile AOM symptom episodes were linked to GP-consultations and diagnoses in the GP electronic health records. RESULTS: With an estimated 624 parent-reported symptom episodes per 1,000 child-years (95% CI: 577 to 674) incidence of febrile AOM symptoms during the child's first year is high. The GP was consulted in half of these symptom episodes and AOM was diagnosed in 49% of these consultations. CONCLUSIONS AND RELEVANCE: The incidence of febrile AOM symptoms in the first year of life is high in Dutch children and leads to a GP-consultation in only half of the cases. This suggests that AOM symptomatology in the community is underestimated when focusing on GP-diagnosed AOM episodes alone, since a considerable proportion of febrile AOM symptom episodes are treated symptomatically by parents at home and do not come to the attention of the GP. Having data on community AOM symptomatology available for each country is important when the potential impact of preventive and therapeutic interventions for AOM are studied.

Pneumococcal conjugate vaccines for preventing otitis media.

BACKGROUND: Acute otitis media (AOM) is a very common respiratory infection in early infancy and childhood. The marginal benefits of antibiotics for AOM in low-risk populations in general, the increasing problem of bacterial resistance to antibiotics and the huge estimated direct and indirect annual costs associated with otitis media (OM) have prompted a search for effective vaccines to prevent AOM. OBJECTIVES: To assess the effect of pneumococcal conjugate vaccines (PCVs) in preventing AOM in children up to 12 years of age. SEARCH METHODS: We searched CENTRAL (2013, Issue 11), MEDLINE (1995 to November week 3, 2013), EMBASE (1995 to December 2013), CINAHL (2007 to December 2013), LILACS (2007 to December 2013) and Web of Science (2007 to December 2013). SELECTION CRITERIA: Randomised controlled trials (RCTs) of PCVs to prevent AOM in children aged 12 years or younger, with a follow-up of at least six months after vaccination. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data. MAIN RESULTS: We included 11 publications of nine RCTs (n = 48,426 children, range 74 to 37,868 per study) of 7- to 11-valent PCV (with different carrier proteins). Five trials (n = 47,108) included infants, while four trials (n = 1318) included children aged one to seven years that were either healthy (one study, n = 264) or had a previous history of upper respiratory tract infection (URTI), including AOM. We judged the methodological quality of the included studies to be moderate to high. There was considerable clinical diversity between studies in terms of study population, type of conjugate vaccine and outcome measures. We therefore refrained from pooling the results.In three studies, the 7-valent PCV with CRM197 as carrier protein (CRM197-PCV7) administered during early infancy was associated with a relative risk reduction (RRR) of all-cause AOM ranging from -5% in high-risk children (95% confidence interval (CI) -25% to 12%) to 7% in low-risk children (95% CI 4% to 9%). Another 7-valent PCV with the outer membrane protein complex of Neisseria meningitidis (N. meningitidis) serogroup B as carrier protein, administered in infancy, did not reduce overall AOM episodes, while a precursor 11-valent PCV with Haemophilus influenzae (H. influenzae) protein D as carrier protein was associated with a RRR of all-cause AOM episodes of 34% (95% CI 21% to 44%).A 9-valent PCV (with CRM197 carrier protein) administered in healthy toddlers was associated with a RRR of (parent-reported) OM episodes of 17% (95% CI -2% to 33%). CRM197-PCV7 followed by 23-valent pneumococcal polysaccharide vaccination administered after infancy in older children with a history of AOM showed no beneficial effect on first occurrence and later AOM episodes. In a study in older children with a previously diagnosed respiratory tract infection, performed during the influenza season, a trivalent influenza vaccine combined with placebo (TIV/placebo) led to fewer all-cause AOM episodes than vaccination with TIV and PCV7 (TIV/PCV7) when compared to hepatitis B vaccination and placebo (HBV/placebo) (RRR 71%, 95% CI 30% to 88% versus RRR 57%, 95% CI 6% to 80%, respectively) indicating that CRM197-PCV7 after infancy may even have negative effects on AOM. AUTHORS' CONCLUSIONS: Based on current evidence of the effects of PCVs for preventing AOM, the licensed 7-valent CRM197-PCV7 has modest beneficial effects in healthy infants with a low baseline risk of AOM. Administering PCV7 in high-risk infants, after early infancy and in older children with a history of AOM, appears to have no benefit in preventing further episodes. Currently, several RCTs with different (newly licensed, multivalent) PCVs administered during early infancy are ongoing to establish their effects on AOM. Results of these studies may provide a better understanding of the role of the newly licensed, multivalent PCVs in preventing AOM. Also the impact on AOM of the carrier protein D, as used in certain pneumococcal vaccines, needs to be further established.