Infant Vaccination Research Articles

A237 ROTAVIRUS VACCINE SAFETY IN INFANTS EXPOSED TO BIOLOGICS IN UTERO IN AN INFLAMMATORY BOWEL DISEASE POPULATION: A PROSPECTIVE COHORT STUDY

Abstract Background Biologics, the mainstay of therapy in patients with moderate-to-severe inflammatory bowel disease (IBD), undergo placental transfer during the second trimester of pregnancy and may remain detectable in the blood of exposed infants for up to 12 months. Due to concerns regarding the risk of immunosuppression and adverse events following immunization with live attenuated vaccines in infants exposed to biologics in utero, current guidelines recommend avoiding live vaccines in the first 6 to 12 months of life. Aims This study investigates whether the live rotavirus vaccine can safely be administered in infants exposed to biologics in utero. Methods We conducted a single-centre prospective cohort study, which included infants exposed to biologics in utero and born to mothers with IBD between October 1, 2020 and June 30, 2022. Infants were included in the study if they were assessed by Paediatric specialists at the Special Immunization Clinic (SIC) at SickKids Hospital (Toronto, Ontario). Mothers were followed by Gastroenterologists at the Special Pregnancy IBD Clinic at Mount Sinai Hospital (Toronto, Ontario). Data were collected on biologic agent exposure history, infant immune function testing, SIC recommendations for rotavirus vaccination, rotavirus vaccine series completion, and adverse events after immunization. Adverse events following immunization included fevers, vomiting, diarrhea, and/or intussusception within 42 days following immunization. Results 22 infants were included in the study. Of the 22 infants, 5 (22.7%) were exposed to infliximab in utero, 10 (45.5%) were exposed to adalimumab, 3 (13.6%) were exposed to vedolizumab, and 3 (13.6%) were exposed to ustekinumab. Of the 22 infants, 18 (81.8%) were recommended to receive the rotavirus vaccine by the SIC. 1 (0.05%) was not recommended to receive the vaccine due to neutropenia and low CD54 count on lymphocyte testing. The recommendation given to 3 infants is unknown. Of the 18 infants who were recommended to receive the vaccine, 16 (88.9%) received the vaccine and had no adverse events following immunization. 1 (6%) infant did not receive the rotavirus vaccine despite it being recommended due to parental choice. The rotavirus vaccination status and response in 1 infant recommended to receive the vaccine, is unknown. Conclusions Administration of the rotavirus vaccine in biologic-exposed infants did not result in adverse events in our study cohort. Although guidelines currently advise against live vaccinations in infants exposed to biologics in utero, specialist assessment of infant immune function can help encourage safe live vaccination uptake. Funding Agencies None

Thrombocytosis and Transaminitis in Infants Born to Women With Inflammatory Bowel Disease Is Associated With Exposure to Maternal Inflammation In Utero

Abstract Background Despite reassuring clinical safety data, thrombocytosis, anemia, lymphopenia, and liver function derangements have been observed in infants born to women with inflammatory bowel disease (IBD) treated with thiopurines and biologics. We aimed to define the prevalence, course, associations, and clinical impact of hematological and biochemical abnormalities in such infants. Methods This multicenter prospective cohort study assessed clinical, hematologic, and biochemical outcomes of infants exposed to thiopurines or biologics in utero for management of maternal IBD. Liver transaminases, full blood examination, and infant thiopurine metabolites (where exposed) were taken at delivery and 6 weeks of age. Abnormal results were repeated until normalization. Infants were followed clinically by a pediatric gastroenterologist up to 2 years of age. Results A total of 130 infants were included. Thrombocytosis and elevated alanine transaminase (ALT) were seen in over half of infants up to 6 months of age with no significant clinical impact. Elevated ALT was associated with increasing maternal C-reactive protein in second trimester, while thrombocytosis was associated with increasing maternal C-reactive protein and fecal calprotectin in third trimester. Preceding infection and vaccination were associated with an increased risk of elevated alkaline phosphatase at 3 months. In those exposed to thiopurines, increasing maternal 6-methylmercaptopurine at delivery was associated with increased ALT to 6 months. Conclusions Infants born to women with IBD commonly developed thrombocytosis, elevated alkaline phosphatase, and elevated ALT. These findings were associated with exposure to maternal inflammation, elevated 6-methylmercaptopurine at delivery, and infant vaccinations and infections, and had minimal clinical consequence.

Inadequate pregnancy-specific knowledge among patients with inflammatory bowel disease: A multicenter survey in China.

The perceptions and attitudes of inflammatory bowel disease (IBD) patients towards pregnancy may affect their fertility plan and disease progression. We performed a nationwide multicenter survey of pregnancy-related knowledge among gastroenterologists and IBD patients in China to investigate whether specific educational interventions could improve their understanding and broadly influence fertility plan. A cross-sectional questionnaire regarding pregnancy-specific knowledge was carried out among 63 IBD centers in China. Questionnaires were collected from 185 physicians and 609 patients. The patients then received education regarding pregnancy during IBD and filled in the same questionnaire again. Their knowledge regarding pregnancy during IBD was compared before and after education. Compared to physicians, patients' knowledge regarding fertility (39.1% vs 70.8%), imaging examinations (22.8% vs 72.4%), endoscopy performed during pregnancy (19.9% vs 71.4%), and vaccination for infants (16.6% vs 46.5%) was significantly more limited (all P < 0.001). There was a lack of knowledge among gastroenterologists regarding the delivery mode (36.8%), medications (36.8%), and emergency surgery (26.5%) during pregnancy in patients with IBD. After education, the patients showed significant improvement in knowledge regarding medications (26.7% vs 51.7%), fertility (45.0% vs 63.3%), heritability (40.0% vs 58.3%), indications for emergency surgery (15.0% vs 53.3%), imaging examinations during pregnancy (20.0% vs 40.0%), and vaccinations for infants (26.7% vs 45.0%) (all P < 0.05). Pregnancy-specific IBD knowledge needs to be improved among certain gastroenterologists and patients in China. Educational interventions can partially improve the knowledge levels of the patients.

Age-dependent acquisition of IgG antibodies to Shigella serotypes-a retrospective analysis of seroprevalence in Kenyan children with implications for infant vaccination.

Shigellosis mainly affects children under 5 years of age living in low- and middle-income countries, who are the target population for vaccination. There are, however, limited data available to define the appropriate timing for vaccine administration in this age group. Information on antibody responses following natural infection, proxy for exposure, could help guide vaccination strategies. We undertook a retrospective analysis of antibodies to five of the most prevalent Shigella serotypes among children aged <5 years in Kenya. Serum samples from a cross-sectional serosurvey in three Kenyan sites (Nairobi, Siaya, and Kilifi) were analyzed by standardized ELISA to measure IgG against Shigella sonnei and Shigella flexneri 1b, 2a, 3a, and 6. We identified factors associated with seropositivity to each Shigella serotype, including seropositivity to other Shigella serotypes. A total of 474 samples, one for each participant, were analyzed: Nairobi (n = 169), Siaya (n = 185), and Kilifi (n = 120). The median age of the participants was 13.4 months (IQR 7.0-35.6), and the male:female ratio was 1:1. Geometric mean concentrations (GMCs) for each serotype increased with age, mostly in the second year of life. The overall seroprevalence of IgG antibodies increased with age except for S. flexneri 6 which was high across all age subgroups. In the second year of life, there was a statistically significant increase of antibody GMCs against all five serotypes (p = 0.01-0.0001) and a significant increase of seroprevalence for S. flexneri 2a (p = 0.006), S. flexneri 3a (p = 0.006), and S. sonnei (p = 0.05) compared with the second part of the first year of life. Among all possible pairwise comparisons of antibody seropositivity, there was a significant association between S. flexneri 1b and 2a (OR = 6.75, 95% CI 3-14, p < 0.001) and between S. flexneri 1b and 3a (OR = 23.85, 95% CI 11-54, p < 0.001). Children living in low- and middle-income settings such as Kenya are exposed to Shigella infection starting from the first year of life and acquire serotype-specific antibodies against multiple serotypes. The data from this study suggest that Shigella vaccination should be targeted to infants, ideally at 6 or at least 9 months of age, to ensure children are protected in the second year of life when exposure significantly increases.

Side Effect Profile of Meningococcal B Vaccine in Children

Objective: Invasive meningococcal infections have a clinical picture with a rapid onset and can lead to serious sequelae and death even in individuals who are treated early. The most common causes of related epidemics are serogroups A, B, C, W, Y, and X, and two different vaccines have been developed against serogroups A, C, W, and Y and serogroup B. The serogroup B-containing MenB-4C vaccine (Bexsero®) was licensed in Turkey in 2018 and is still being administered. In this study, the side effects of this vaccine in infants and children followed up in a tertiary pediatric clinic were questioned. Materials and Methods: In our study, the local and systemic side effects of the MenB-4C vaccine doses, which were administered between March 1, 2019, and March 1, 2022, at the Child Health Follow-up Outpatient Clinic of Gazi University Faculty of Medicine, were evaluated retrospectively. All infants and children aged 0-18 years who were vaccinated at this clinic on the specified dates (n = 102) were recruited, and a questionnaire was completed by calling their parents by telephone and questioning the side effects of the vaccine. Results: It was determined that a total of 224 doses of the MenB-4C vaccine were administered to 102 children over the three-year study period, Of these vaccines, 21.6% were administered during the year before the pandemic and 78.4% during the two years after the pandemic. According to the total number of doses, the rate of local and systemic side effects was 30.8% (n= 69). It was found that among the 69 doses with side effects, 42 (60.8%) were systemic (fever), and 27 (39.1%) were local (stiffness, redness, and pain at the injection site). Side effects were observed in 41.3% of the patients after the first dose of the vaccine, 23.3% after the second dose, and 25.9% after the third dose. Conclusion: In our study, no serious post-vaccine reactions, such as anaphylaxis and encephalopathy, were observed following vaccination with MenB-4C, and the most common side effects of this vaccine were fever and local pain, which were only transient and self-limiting, lasting only two to three days at most. Since the MenB-4C vaccine, which has been included in the vaccination schedule of most countries, is a strong tool to help prevent meningococcal infections, every parent presenting to a health institution should be informed by the physician about the necessity of this vaccine, and if possible, conjugated meningococcal vaccines containing not only serogroups A, C, W, and Y but also serogroup B should be added to the national vaccine scheme.

Immune Persistence following Primary Immunization and the Immunogenicity and Safety of a Booster Dose of a Multidose Sabin Strain-Based Inactivated Polio Vaccine in Infants Aged 18 Months.

The multidose Sabin-strain inactivated poliovirus vaccine (sIPV) has the potential to significantly aid in the eradication of poliomyelitis, particularly in low- and middle-income countries. As part of a phase III clinical trial in which infants were given three doses of primary immunization at 2, 3, and 4 months of age, this study aimed to evaluate immune persistence following primary immunization, as well as the safety and immunogenicity of a booster of the 5-dose sIPV in infants aged 18 months. Infants aged 18 months were given one booster dose of 5-dose sIPV in stage one, which was open-label. Unblinding was performed for stage two after completing primary immunization, which was randomized, blinded, and controlled; infants aged 18 months in the test group I-III, IPV group, and single-dose sIPV group were given one booster dose of 5-dose sIPV, conventional IPV, and single-dose sIPV, respectively, in stage two. This study included 1438 infants in the immune persistence and safety set and 1387 infants in the booster per-protocol set. Fourteen months after primary immunization, the seropositivity rates (≥1:8) for types 1-3 were 100%, 99.88%, and 99.53% in the 5-dose sIPV groups; 100%, 98.97%, and 97.23% in the IPV group; and 99.66%, 100%, and 99.66% in the single-dose sIPV group. A total of 30 days after booster immunization, the seropositivity rates (≥1:8) of 3 serotypes in all the groups reached 100%. The geometric mean titers of neutralizing antibodies for types 1-3 in the 5-dose sIPV group were 9962.89, 10273, and 7870.21, with geometric mean increases of 15.76, 33.15, and 24.5, compared to the pre-booster level. The overall incidence of adverse reactions was 8.97%, with fever being the most common, observed at rates of 7.1%, 5.52%, and 7.96% in the 5-dose sIPV, IPV, and single-dose groups, respectively (p = 0.4845). The 5-dose sIPV has shown promising immune persistence and robust immune response following a booster immunization, coupled with an acceptable safety profile.

Clinical research on RSV prevention in children and pregnant women: progress and perspectives.

Respiratory syncytial virus (RSV) is a significant causative agent of bronchitis and pneumonia in infants and children. The identification and structural analysis of the surface fusion glycoprotein of RSV represents a pivotal advancement in the development of RSV prevention. This review provides a comprehensive summary of RSV monoclonal antibody (mAb) and vaccine clinical trials registered on ClinicalTrials.gov, emphasizing on the classification, name, target, phase, clinical outcomes, and safety data of RSV vaccination in newborns, infants and children. We also discuss the characteristics of the types of RSV vaccines for maternal immunity and summarize the current clinical research progress of RSV vaccination in pregnant women and their protective efficacy in infants. This review will provide new ideas for the development of RSV prevention for children in the future.

Maternal singing reduced pain indexes in 2-month-old infants and increased proximity during vaccinations.

Immunisation is a global health priority, but methods of non-pharmacological pain relief are not widely used in routine clinical practice. In this study, we set out to investigate the effects of maternal singing during the routine vaccination of infants. We recruited 67 mother-infant pairs at Health Centres in the Aosta Region of Italy. Infants aged 2-4 months were randomly allocated to a singing intervention group or to a control group whose injections were administered following standard practice. Pre- and post-immunisation pain was blindly assessed using the Modified Behavioural Pain Scale, and mother-infant proximity indexes were assigned based on muted video-tracks. When assessed for pain, the infants in the maternal singing group were assigned significantly lower movement indexes (p = 0.032) and marginally significantly lower cry indexes (p = 0.076). A higher frequency of mother-to-infant gaze (p < 0.005) was observed in the singing group dyads. Finally, the intervention group mothers' self-perceived ease in singing was correlated with their previous singing experience and with lower anxiety following the vaccination procedure (p < 0.05). Maternal singing during immunisation procedures benefits both mothers and babies. The practice of singing is a biologically rooted and adaptive form of intuitive parental communication that should be encouraged, especially in at-risk populations.

A phase 3 randomized study to evaluate safety and immunogenicity of 20-valent pneumococcal conjugate vaccine in healthy Japanese infants

ObjectivesSafety and immunogenicity evaluation of a 4-dose series with 20-valent pneumococcal conjugate vaccine (PCV20). MethodsThis phase 3, double-blind study randomized healthy Japanese infants to receive 4 doses (3 infant doses, 1 toddler dose) of PCV20 by subcutaneous (SC) or intramuscular (IM) injection or 13-valent PCV (PCV13) SC. A primary immunogenicity objective was to demonstrate noninferiority of PCV20 SC to PCV13 SC for percentages of participants meeting predefined serotype-specific immunoglobulin G concentrations 1 month after Dose 3. The 7 additional PCV20 serotypes were compared with the lowest vaccine serotype result in the PCV13 group. Safety and tolerability were assessed as the primary safety objective. ResultsOverall, 668 participants were randomized (PCV20 SC, n = 226; PCV13 SC, n = 224; PCV20 IM, n = 218). The primary noninferiority objective for PCV20 SC to PCV13 SC was met for 11/13 matched and 5/7 additional serotypes. Additional data showed PCV20 SC and IM elicited robust functional opsonophagocytic activity and boosting responses to all 20 vaccine serotypes. PCV20 had a similar safety/tolerability profile to PCV13, although local reactions were less frequent with PCV20 IM. ConclusionsA 4-dose series of PCV20 SC or IM elicited immune responses expected to be protective against all 20 serotypes in Japanese infants. NCT04530838

Risk and rates of hospitalisation in young children: A prospective study of a South African birth cohort.

Children in sub-Saharan Africa (SSA) are disproportionately affected by morbidity and mortality. There is also a growing vulnerable population of children who are HIV-exposed uninfected (HEU). Understanding reasons and risk factors for early-life child hospitalisation will help optimise interventions to improve health outcomes. We investigated hospitalisations from birth to two years in a South African birth cohort study. Mother-child pairs in the Drakenstein Child Health Study were followed from birth to two years with active surveillance for hospital admission and investigation of aetiology and outcome. Incidence, duration, cause, and factors associated with child hospitalisation were investigated, and compared between HEU and HIV-unexposed uninfected (HUU) children. Of 1136 children (247 HEU; 889 HUU), 314 (28%) children were hospitalised in 430 episodes despite >98% childhood vaccination coverage. The highest hospitalisation rate was from 0-6 months, decreasing thereafter; 20% (84/430) of hospitalisations occurred in neonates at birth. Amongst hospitalisations subsequent to discharge after birth, 83% (288/346) had an infectious cause; lower respiratory tract infection (LRTI) was the most common cause (49%;169/346) with respiratory syncytial virus (RSV) responsible for 31% of LRTIs; from 0-6 months, RSV-LRTI accounted for 22% (36/164) of all-cause hospitalisations. HIV exposure was associated with increased incidence rates of hospitalisation in infants (IRR 1.63 [95% CI 1.29-2.05]) and longer hospital admission (p = 0.004). Prematurity (HR 2.82 [95% CI 2.28-3.49]), delayed infant vaccinations (HR 1.43 [95% CI 1.12-1.82]), or raised maternal HIV viral load in HEU infants were risk factors for hospitalisation; breastfeeding was protective (HR 0.69 [95% CI 0.53-0.90]). In conclusion, children in SSA experience high rates of hospitalisation in early life. Infectious causes, especially RSV-LRTI, underly most hospital admissions. HEU children are at greater risk of hospitalisation in infancy compared to HUU children. Available strategies such as promoting breastfeeding, timely vaccination, and optimising antenatal maternal HIV care should be strengthened. New interventions to prevent RSV may have additional impact in reducing hospitalisation.

Infant Whole-Cell Versus Acellular Pertussis Vaccination in 1997 to 1999 and Risk of Childhood Hospitalization for Food-Induced Anaphylaxis: Linked Administrative Databases Cohort Study

Evidence suggests that children who had received an initial priming dose of whole-cell pertussis (wP) vaccine, rather than acellular pertussis (aP) vaccine, had a lower risk of developing IgE-mediated food allergy, the most common cause of anaphylaxis-related hospital presentations ofchildhood. To assess the association between wP versus aP vaccination in infancy and subsequent hospital presentations for anaphylaxis. This study was preregistered under PMID 34874968. Perinatal records for a cohort of New South Wales-born children (1997-1999) receiving their first dose of pertussis-containing vaccine before age 4 months were probabilistically linked to hospital and immunization records. We used adjusted Cox models to estimate hazard ratios (aHRs) and 95% CIs for anaphylaxis-coded hospitalizations. There were 218,093 New South Wales-born children who received a first dose of wP or aP before age 4 months. Among these children, 86 experienced at least one hospitalization for food-induced anaphylaxis at age 5-15 years (range of events per patient, one to three). The person-time of follow-up was 1,476,969 years, and 665,519 years for children vaccinated with wP as a first dose (wP-1 children) and aP as a first dose (aP-1 children), respectively. The incidence rates for first hospitalization for food anaphylaxis were 3.5 (95% CI, 2.6-4.6) and 5.1 (95% CI, 3.5-7.1) per 100,000 child-years among wP-1 children and aP-1 children, respectively (aHR for wP vs aP= 0.47; 95% CI, 0.26-0.83). For first admission for venom anaphylaxis, the incidence rate was 4.9 (95% CI, 3.9-6.2) per 100,000 child-years among wP-1 children and 5.1 (95% CI, 3.5-7.1) per 100,000 child-years among aP-1 children (aHR for wP vs aP= 0.92; 95% CI, 0.53-1.60), and for all-cause anaphylaxis, the incidence rate was 10.6 (95% CI, 9.0-12.4) per 100,000 child-years among wP-1 children and 12.8 (95% CI, 10.2-15.8) per 100,000 child-years among aP-1 children (aHR for wP vs aP= 0.92; 95% CI, 0.53-1.60). Vaccination with wP in infancy was associated with a lower risk of hospitalizations for food-induced anaphylaxis (and therefore severe IgE-mediated food allergy) occurring in childhood.

The effect of breastfeeding on reducing pain induced by pentavalent vaccine in infants: a randomized clinical trial

RESUMO Objetivo: Analisar o efeito da amamentação na redução da dor induzida pela vacina Pentavalente em lactentes e identificar o intervalo de tempo da amamentação necessário para sua ação antinocicepção. Método: Ensaio clínico randomizado paralelo aberto. Participaram 90 binômios mãe-lactente, distribuídos em grupo intervenção 1 (n = 30), que realizou a amamentação cinco minutos antes da vacinação; grupo intervenção 2 (n = 30), realizou a amamentação cinco minutos antes e durante a vacinação; e grupo controle (n = 30), que não realizou a amamentação. A variável desfecho foi o nível de dor mensurado pela Escala FLACC. A análise dos dados foi realizada por meio de estatística descritiva e inferencial, com aplicação dos testes Exato de Fisher, Kolmogorov-Smirnov, Kruskal-Wallis e de comparações múltiplas de Dunn, adotando nível de significância de 0,05. Resultados: A dor induzida pela vacina Pentavalente se reduziu nos grupos intervenção 1 e 2 (média de dor de 6,06 versus 3,83, respectivamente) em comparação ao grupo controle (média de dor de 7,43), o que foi significativo para o grupo intervenção 2 (p &lt; 0,001), indicando que, para alcançar menores níveis de dor, a amamentação deve ocorrer antes e durante a vacinação. Conclusão: A amamentação mais prolongada, realizada cinco minutos antes e durante todo o processo de vacinação, reduz a dor induzida pela vacina Pentavalente. Em sua aplicação não foram identificados riscos capazes de superar os benefícios de tal prática. Esses resultados endossam a importância de os profissionais de saúde incentivarem essa prática no tempo mínimo de cinco minutos antes e durante a aplicação de vacinas injetáveis para obtenção do efeito antinocicepção. Registro Brasileiro de Ensaios Clínicos: RBR-9vh37wr.

The effect of breastfeeding on reducing pain induced by pentavalent vaccine in infants: a randomized clinical trial.

To analyze the effect of breastfeeding on reducing Pentavalent vaccination pain in infants and to identify the necessary breastfeeding interval for antinociceptive action. Open parallel randomized clinical trial. Ninety mother-infant dyads participated, distributed into intervention group 1 (n = 30), which breastfed five minutes before vaccination; intervention group 2 (n = 30), which breastfed five minutes before and during vaccination; and control group (n = 30), which did not breastfeed. The outcome variable was the pain level measured by the FLACC Scale. Data analysis was conducted using descriptive and inferential statistics, applying Fisher's Exact, Kolmogorov-Smirnov, Kruskal-Wallis and Dunn's multiple comparison tests, with 0.05 significance level. Pain induced by the Pentavalent vaccine was reduced in intervention groups 1 and 2 (mean pain of 6.06 versus 3.83, respectively) compared to the control group (mean of pain of 7.43), which was significant for intervention group 2 (p < 0.001), indicating that, to achieve lower levels of pain, breastfeeding should be carried out before and during vaccination. Longer breastfeeding, conducted five minutes before and during vaccination, reduces the pain induced by the Pentavalent vaccine. No vaccination risks were identified to outweigh the benefits. These results endorse that health professionals should encourage breastfeeding at least five minutes before and during vaccine injection for an antinociception effect. Brazilian Clinical Trials Registry: RBR-9vh37wr.

Use of private vaccination services by infants in Brazilian municipalities: National Vaccine Coverage Survey 2020.

To characterize the use of private services in infant vaccination and assess vaccination coverage according to the service used. : This was a national vaccination survey conducted in 2020 that estimated the use of private vaccination services and vaccination coverage among infants residing in state capitals and 12 inland municipalities. : Of the 37,801 participants, 25.1% (95%CI 23.2;27.2) used private services at least once, with higher proportions in capitals, larger cities and in the South and Southeast regions. Socioeconomic and demographic differences were identified among families, based on the service used. The coverage for the set of vaccines administered up to 24 months was 60.3% (95%CI 58.6;62.0) in the public service and 59.5% (95%CI 55.9;63.0) in private services, and up-to-date vaccines, 10.3% (95%CI 9.1;11.6) and 9.4% (95%CI 7.4;11.8), respectively. The use of private services was frequent, with low coverage for the set of vaccines, regardless of the type of service used, especially for up-to-date vaccines.

Vaccination coverage and delay in vaccination of infants born in 2017 and 2018 in municipalities in the Southern region of Brazil: National Vaccination Coverage Survey 2020.

To evaluate vaccination coverage and delay in vaccine dose administration in infants in six municipalities in the Southern region of Brazil. National Vaccination Coverage Survey 2020, with infants born alive in 2017 and 2018, carried out from September 2020 to March 2022. Coverage of doses administered, doses administered on time and delay in dose administration were evaluated. For 4681 infants analyzed, coverage for vaccines recommended up to 24 months was 68.0% (95%CI 63.9;71.8%) for doses administered and 3.9% (95%CI 2.7%;5.7%) for doses administered on time. Delay time for the majority of late vaccinations was ≤ 3 months. For some boosters, 25% of vaccine administration was delayed by ≥ 6 months. In addition to tracking vaccine defaulters, strategies are needed to encourage compliance with the vaccination schedule at the recommended ages. Vaccination coverage for the set of vaccines recommended up to 24 months was 68.0% and 3.9% for on-time doses. Delay time for some doses exceeded six months in up to 25% of infants with delayed vaccination. Monitoring vaccine administration at the recommended ages is necessary, with the adoption of strategies that reinforce routine vaccination to prevent vaccination delays and abandonment. Primary care in surveillance and care for infants needs to reinforce actions to ensure timely vaccination. Studies to deepen knowledge of vaccination delay, determinants and strategies for their reduction are necessary.

Vaccination coverage and delay in vaccination of infants born in 2017 and 2018 in municipalities in the Southern region of Brazil: National Vaccination Coverage Survey 2020

RESUMO Objetivo Avaliar as coberturas vacinais e o atraso nas doses de vacinas em lactentes em seis municípios da região Sul do Brasil. Metodologia Inquérito Nacional de Cobertura Vacinal 2020, com lactentes nascidos vivos em 2017 e 2018, realizado entre setembro de 2020 e março de 2022. Foram avaliadas as coberturas de doses aplicadas, doses em dia e o tempo de atraso da aplicação. Resultados Para 4.681 lactentes analisados, as coberturas para vacinas indicadas até os 24 meses foram de 68,0% (IC95% 63,9;71,8) para doses aplicadas e 3,9% (IC95% 2,7;5,7) para doses em dia. A maioria das aplicações em atraso foi ≤ 3 meses. Para alguns reforços, 25% das aplicações atrasaram ≥ 6 meses. Conclusão Além da busca de faltosos às vacinas, são necessárias estratégias para estímulo ao cumprimento do esquema de vacinação nas idades preconizadas.

An indirect treatment comparison (ITC) and matching-adjusted indirect comparison (MAIC) between a 15-valent (V114) and a 20-valent (PCV20) pneumococcal conjugate vaccine among healthy infants

ABSTRACT Objectives Immunogenicity between 15-valent V114 (PCV15) and 20-valent PCV20 pneumococcal conjugate vaccines in healthy infants is compared in an indirect treatment comparison and matching-adjusted indirect comparison. Hypotheses: immunogenicity of V114 is non-inferior to PCV20 for all PCV13 serotypes, and superior to PCV20 for serotype 3 based on lower bound margins. Methods Two phase 3 pivotal studies on 3 + 1 pediatric vaccination schedule at age 2, 4, 6, and 12–15 months compared V114 (N = 858) to PCV13 (N = 856) and PCV20 (N = 1001) to PCV13 (N = 987). Infant’s age and race in V114 study were matched to those in PCV20 study. Primary endpoints were serotype-specific Immunoglobulin G (IgG) response rate difference (RRD) 30 days post-dose (PD)3; IgG geometric mean concentration (GMC) ratios 30 days PD3 and PD4. Results V114 was non-inferior ( >-10%-point; >0.5) to PCV20 (p-value <0.001) for all endpoints. V114 was superior ( >0%-point; >1.2) to PCV20 (p-value <0.001) for serotype 3: RRD was 34.5% (95%CI 27.9%-41.1%) PD3, and IgG GMC ratios were 2.39 (95%CI 2.12–2.68) PD3 and 2.15 (95%CI 1.90–2.41) PD4. Conclusion Immune response to V114 administered in a 3 + 1 schedule in healthy infants was considered non-inferior to PCV20 for all 13 PCV13 serotypes and superior for serotype 3 PD3 and PD4. Clinical trial registration www.clinicaltrials.gov identifiers NCT03893448, NCT04382326

Vaccination against pertussis in Latin American preterm and low-birth weight infants: experts opinion position for a neglected childhood age group

ABSTRACTBackgroundPertussis remains as one of the oldest leading vaccine-preventable diseases of childhood, despite many decades of primary vaccine doses’ and boosters’ implementation. Although the epidemiology is well understood in infants and children, premature babies and low-birth weight infants remain a special group where the disease incidence is unknown, severity of the disease is considerable, and specific vaccination recommendations are scarce.Research design and methodsA retrospective review of the available evidence of pertussis vaccination in premature and low birth weight infants was analyzed from January 2000 to December 2022 in six selected countries: Argentina, Mexico, Colombia, Panamá, Costa Rica, and Chile.ResultsChile had reports of adverse effects associated with vaccination of premature infants with the pentavalent vaccine, and their rationale to switching to the hexavalent vaccine. Colombia had reports of the justification for the use of hexavalent vaccine in prematures in the Neonatal Units and Kangaroo Mother Programs throughout the country. Mexico had selected publications of the vaccination status in prematures and low-birth weight infants.ConclusionDespite its importance, increased morbidity, and highest risk of complications in premature babies, there is a paucity of information of vaccine recommendations and coverage rates among selected Latin American infants.

Routine pediatric vaccinations during the COVID-19 pandemic: A review of the global impact.

The coronavirus disease 2019 (COVID-19) pandemic has put standard, routine childhood vaccinations at risk worldwide. The disruption in vaccine coverage has resulted in a negative impact on the health of children, with some races, ethnicities, age groups, areas of settlement, and parts of the world affected more than others. This literature review studied and examined the impact of COVID-19 on infant, child, and adolescent vaccinations. Retrospectively, the analysis showed a decline, delays, or interruptions in the coverage of vaccines during the pan-demic and a decline in some countries' pre-pandemic and post-pandemic eras. Necessary attempts and efforts should be made for these delayed and missed vaccinations, as failure to do so could put children's health at risk. Thus, priority should be directed at instituting catch-up programs to support vaccine uptake and decrease the probability of acquiring vaccine-preventable diseases.

Along came COVID-19: The changing landscape of serious childhood infections

The landscape of acute childhood infections changed dramatically across Europe in the immediate post-COVID-19 period. It was initially characterised by an unprecedented reduction of children with acute infections and reduced circulation of infectious pathogens in the community. With the lifting of non-pharmaceutical interventions (NPI) and return of circulating organisms, we witnessed re-emergence of infectious pathogens. We learned about the impact of NPIs on childhood infections and should learn from this for future outbreaks, balancing immediate need for interrupting population transmission with longer term rebound effects. Outbreaks of monkeypox, severe childhood hepatitis of unclear aetiology, and invasive Group A Streptococcus each presented with unique clinical dilemmas requiring urgent scientific evidence and public health messaging. Implementation of maternal and infant RSV vaccines, as well as other promising vaccine developments, will further impact the landscape of acute childhood infections.