Respiratory infections in children up to two years of age on prophylaxis with palivizumab

Temporal-spatial analysis of hospitalizations for bronchiolitis in Brazil: prediction of epidemic regions and periods for immunization against the Respiratory Syncytial Virus

OBJECTIVE

Due to the high cost and short term of passive immunization against the respiratory syncytial virus, the main virus causing acute viral bronchiolitis, predicting epidemic regions and epidemic months is extremely important. The objective of this study is to identify both the month when the seasonal peak begins and Brazilian regions and states with the highest incidence of monthly hospitalizations due acute viral bronchiolitis.

METHODS

Based on data obtained from DATASUS, monthly hospitalization rates due acute viral bronchiolitis were calculated for every 10,000 live births to children under 12 months of age in all Brazilian states and the Federal District between 2000 and 2019. Seasonal autoregressive integrated moving average models were estimated to forecast monthly hospitalization rates in 2020.

RESULTS

A higher incidence of hospitalizations was found for male children, especially under six months of age. As for Brazilian regions, between 2000 and 2019, the South region registered the highest incidence of hospitalizations, followed by the Southeast, Midwest, North and Northeast regions, in this order. Considering the seasonal peak, the period between March and July 2020 comprised the highest expected hospitalization rates.

CONCLUSIONS

Palivizumab is suggested to be started between February/March and June/July for most Brazilian states, with the exception of Rio Grande do Sul, which, in addition to presenting the highest rates of hospitalizations for acute viral bronchiolitis per 10,000 live births, has the longest seasonal peak between May and September.

A post-incorporation study on the use of palivizumab in the Brazilian public health system

Respiratory syncytial virus (RSV) is the main cause of lower respiratory disease in infants and children under five years of age. As there is no specific treatment for RSV infections, prophylaxis with the specific monoclonal antibody palivizumab (PVZ) has been widely recommended for high-risk cases during the RSV season. The present study aimed to evaluate the effectiveness of a public prophylaxis program with palivizumab on the incidence of hospitalizations for lower respiratory tract infections and RSV in children at high risk for severe RSV infections. A retrospective cohort study was carried out with preterm children or children under two years of age with chronic lung disease or hemodynamically significant congenital heart disease; the children were selected on the basis of their exposure status, which was defined as the prophylactic use of palivizumab during the RSV season. Children were enrolled retrospectively in two hospitals located in Southern Brazil, from May 2009 to August 2016. In a sample of 129 children, 69 (53.5%) received palivizumab and adherence to three or more doses was observed in 78%; 60 (46.5%) children did not receive palivizumab. PVZ prophylaxis was independently associated with a 66% reduction in hospitalizations for any cause (26/69 - 37.7%) in the PVZ group and 34/60 (56.7%) in the control group). A 52% reduction in hospitalizations due to lower respiratory tract infection was observed in the PVZ group (15/69 -21.7%) and 25/60 (41.7%) in the control group. These findings suggest that, for the group of studied patients, the adoption of an RSV prophylaxis scheme reached the same effectiveness as those described in previous clinical trials.

Updated cost-effectiveness analysis of palivizumab (Synagis) for the prophylaxis of respiratory syncytial virus in infant populations in the UK

AIMS

Respiratory syncytial virus (RSV) is a common cause of respiratory infection in infants and severe infection can result in hospitalization. The passive immunization, palivizumab, is used as prophylaxis against RSV, however, use in the UK is restricted to populations at high risk of hospitalization. This study assesses the cost-effectiveness (CE) of palivizumab in premature infants with and without risk factors for hospitalization (congenital heart disease [CHD], bronchopulmonary dysplasia [BPD]).

METHODS

A decision tree model, based on earlier CE analyses, was updated using data derived from targeted literature reviews and advice gained from a Round Table meeting. All costs were updated to 2019 prices. One-way and probabilistic sensitivity analyses were performed to assess the degree of uncertainty surrounding the results.

RESULTS

Palivizumab is dominant (i.e. clinically superior and cost saving) when used in premature infants born ≤35 weeks gestational age (wGA) without CHD or BPD and aged <6 months at the start of the RSV season, infants aged <24 months with CHD and infants aged <24 months requiring treatment for BPD within the last 6 months.

LIMITATIONS

One-way sensitivity analysis suggests that these results are highly sensitive to the efficacy of prophylaxis, number of doses, impact of long-term respiratory sequalae, rate of hospitalization and mortality due to RSV. A conservative approach has been taken toward long-term respiratory sequalae due to uncertainty around epidemiology and etiology and a lack of recent cost and utility data.

CONCLUSIONS

Palivizumab prophylaxis is cost-effective in preventing severe RSV infection requiring hospital admission in a wider population than currently recommended in UK guidelines. Prophylaxis in premature infants born <29 wGA, 29-32 wGA and 33-35 wGA without CHD or BPD aged <6 months at the start of the RSV season is not funded under current guidance, however, prophylaxis has been demonstrated to be cost-effective in this analysis.

Incidence of respiratory syncytial virus infection in children with congenital heart disease undergoing immunoprophylaxis with palivizumab in Pará state, north region of Brazil

Background

Palivizumab prophylaxis for the human respiratory syncytial virus (HRSV) has been reported to reduce the risk of hospital admissions related to HRSV in children with congenital heart disease (CHD). These children are at high risk of developing severe lower respiratory tract infection (LRTI) due to HRSV infection. Our goal was to evaluate the incidence of HRSV infection in children with CHD after being submitted to immunoprophylaxis with palivizumab in Pará state, North region of Brazil.

Methods

A prospective and observational cohort study was performed in children ≤2 years of age with CHD who received palivizumab immunoprophylaxis between January 1 and June 31, 2016. A questionnaire about basic non-medical care measures was applied to parents/legal representatives. Data on patients’ demographic characteristics, household environment, and respiratory infections were evaluated. HRSV infection was determined by qPCR.

Results

There were 104 children enrolled in this investigation and the results showed a mean age of 10.6 months, an average weight of 7.3 kg and 3.5 doses of palivizumab per children during seasonality of HRSV. Respiratory infection was observed in 27.9% of cases, of which 9.6% were LRTI. No case of children who received palivizumab immunoprophylaxis and developed influenza-like symptoms tested positive for HRSV.

Conclusion

Although the lack of a control group doesn’t allow to affirm the effectiveness of HRSV passive immunization, the immunoprophylaxis with palivizumab appeared to be totally efficient in preventing respiratory infection by HRSV in children up to two years of age with CHD.

[Assessment of the program for use of the monoclonal antibody palivizumab in São Paulo State, Brazil]

This study aimed to assess the program for use of the monoclonal antibody palivizumab in São Paulo State, Brazil. The evaluation adopted the frame of reference proposed by Donabedian, and the data were discussed on the basis of the guidelines from the Ruling on the use of palivizumab in the national network and in the Manual on Standards and Procedures for Vaccination. Sixteen application services in the state were included, with 693 children/mothers enrolled in the program in 2014 (85.1% of the eligible population). For the structure and process evaluation, scores were created that allowed classifying the application services as adequate, partially adequate, and inadequate (non-compliance rates were ≤ 10%, 11-20%, and > 20%, respectively). Results were evaluated according to the association between failure to administer palivizumab and need for hospitalization due to respiratory disease/symptoms, based on the point and interval odds ratios, with 95% confidence interval and critical p-value < 0.05. Of the 11 application services whose structure was classified as adequate, only two showed adequate process, four showed inadequate process, and five partially adequate process. Risk of ICU admission due to respiratory disease/symptoms increased on average by 30% for each failure (p = 0.003; OR = 1.30; 95%CI: 1.09-1.55). In conclusion, having a favorable structure for the program for use of palivizumab in São Paulo State did not necessarily result in an adequate process. In general, the situation with the structure was better than the process. All doses of the monoclonal antibody need to be administered in order to prevent hospitalization from respiratory disease/symptoms.

Impact of the use of immunoglobulin palivizumab in the State of São Paulo: a cohort study

ABSTRACT Introduction: the use of palivizumab as prophylaxis of the respiratory syncytial virus is not a consensus. In Brazil, it is a public health program, but other countries do not consider it cost-effective. Objective: to identify the rate of hospitalization in Intensive Care Unit for respiratory illness or symptoms among children who received the immunoglobulin palivizumab, the proportion of children who failed to take any of the recommended doses and the impact of that failure on hospitalization. Method: cohort study conducted with 693 children enrolled in the palivizumab program in 2014 (85.1% of the population), with monthly assessment from April to September through a telephone call to the mothers or caregiver. The probability of hospitalization in the Intensive Care Unit related to failure in taking the palivizumab, was analyzed through multiple logistic regression, with p<0,05. Results: the hospitalization rate was 18.2%; 2.3% of the children did not receive all the recommended immunoglobulin doses; the probability of hospitalization for respiratory illness or symptoms increased by an average of 29% at each missed dose (p=0.007; OR=1.29, CI=1.07-1.56). Conclusion: the increase in the chance of hospitalization related to missed immunoglobulin doses indicates the need to implement health education actions and active search for absent children by the health services.

One-year observational study of palivizumab prophylaxis on infants at risk for respiratory syncytial virus infection in Latin America

OBJECTIVE

This study aims to describe real world palivizumab use and effectiveness in high-risk Latin American infants and young children.

METHOD

Prospective, multicenter observational study with infants at risk for severe RSV infection who received palivizumab according to routine clinical practice. Subjects were followed for one year with monthly visits after the first dose of palivizumab. An infant was considered adherent if receiving all the expected injections or five or fewer injections within appropriate inter-dose intervals. Annual incidence rates and risk factors of lower respiratory tract infection (LRTI) hospitalization were determined through Poisson regression models (α=0.05).

RESULTS

The study enrolled 458 children from seven countries in Latin America, from February 2011 to September 2012. The majority (98%) were born <36 weeks gestation. Overall, patients received 83.7% of their expected injections and 86.7% completed one year of follow-up. Of the 61 LRTI hospitalizations, 12 episodes were due to RSV infection. The RSV-associated hospitalization rate was 2.9 per 100 patient-years. Bronchopulmonary dysplasia was identified as an independent risk factor for LRTI hospitalization. A total of 1165 adverse events were recorded during one year of follow-up. One hundred and two patients (22.3%) had a total of 135 serious adverse events, but no events were considered to be related to palivizumab.

CONCLUSIONS

The rate of RSV hospitalization in high-risk infants in Latin America was low and aligned with those observed in randomized control trials and observational studies. Palivizumab prophylaxis appeared effective and had a good safety profile in this population.

Evaluation of Reference Centers for Special Immunobiologicals implementation

OBJECTIVE

To describe the Reference Centers for Special Immunobiologicals and evaluate their implementation considering formal regulations.

METHODS

We conducted a program evaluation, of evaluative research type. From August 2011 to January 2012, a questionnaire was applied to the 42 Reference Centers for Special Immunobiologicals existing in the Country, approaching the structure, human resources, and developed activities dimensions. We conducted a descriptive analysis of data and used a clustering for binary data with the squared Euclidean distance, by the farthest neighbor method, to aggregate services with similar features.

RESULTS

We observed great diversity among the services in the three dimensions. The clustering resulted in five service profiles, named according to their characteristics. 1) Best structure: 12 Reference Centers for Special Immunobiologicals with the highest proportion of services with the minimum of rooms recommended, purpose-built vaccine refrigerators, preventive maintenance of the cold chain, and oxygen source. 2) Immunobiologicals distributor: six Reference Centers for Special Immunobiologicals that distributed more than applied immunogens; no doctor present for more than half of the working hours and no purpose-built vaccine refrigerators . 3) Incipient implementation: five Reference Centers for Special Immunobiologicals with inadequate structure, such as absence of purpose-built vaccine refrigerators, preventive maintenance of the cold chain and oxygen source; none had computer. 4) Vaccination rooms: 13 Reference Centers for Special Immunobiologicals, everyone did routine immunization, most participated in vaccination campaigns. 5) Teaching and research: six services, all inserted into teaching hospitals, developed researches and received trainees; most had doctors in more than half of the working hours.

CONCLUSIONS

The evaluation of the Reference Centers for Special Immunobiologicals implementation was based on the profiles found and considered the official regulations: services categorized as "better structure" and "teaching and research" were considered implemented; "immunobiologicals distributor" and "vaccination room" services, partially implemented, and the ones with the "incipient implementation" profile, not implemented. The results of this evaluation can contribute to the reformulation of the services, considering the current context.

OBJETIVO

Descrever os Centros de Referência para Imunobiológicos Especiais e avaliar sua implantação considerando as regulamentações formais.

MÉTODOS

Foi realizada uma avaliação de programa, tipo pesquisa avaliativa. De agosto de 2011 a janeiro de 2012, foi aplicado questionário aos responsáveis pelos 42 Centros de Referência para Imunobiológicos Especiais existentes no País, abordando as dimensões estrutura, recursos humanos e atividades desenvolvidas. Foi feita análise descritiva dos dados e utilizado agrupamento para dados binários com uso da distância euclidiana quadrática, pelo método do vizinho mais distante, para agregar serviços com características semelhantes.

RESULTADOS

Observou-se grande diversidade entre os serviços nas três dimensões. O agrupamento resultou em cinco perfis de serviços, denominados de acordo com suas características. 1) Melhor estrutura: 12 Centros de Referência para Imunobiológicos Especiais com a maior proporção de serviços com o mínimo de salas preconizado, câmaras de vacinas, manutenção preventiva da rede de frio e fonte de oxigênio. 2) Dispensador de imunobiológicos: seis Centros de Referência para Imunobiológicos Especiais que mais dispensavam do que aplicavam imunógenos; sem médico presente por mais da metade do expediente do serviço e sem câmara de vacinas. 3) Implantação incipiente: cinco Centros de Referência para Imunobiológicos Especiais com estrutura inadequada, como ausência de câmaras de vacinas, de manutenção preventiva da rede de frio e de fonte de oxigênio; nenhum possuía computador. 4) Sala de vacinas: 13 Centros de Referência para Imunobiológicos Especiais, todos faziam imunização de rotina, a maioria participava de campanhas de vacinação. 5) Ensino e pesquisa: seis serviços, todos inseridos em hospitais de ensino, desenvolviam pesquisas e recebiam estagiários; a maioria possuía médicos em mais da metade do expediente.

CONCLUSÕES

A avaliação de implantação dos Centros de Referência para Imunobiológicos Especiais baseou-se nos perfis encontrados e considerou as regulamentações oficiais: os serviços categorizados como "melhor estrutura" e "ensino e pesquisa" foram considerados implantados; os serviços "dispensador de imunobiológicos" e "sala de vacinas", parcialmente implantados e os do perfil "implantação incipiente", não implantados. Os resultados dessa avaliação podem contribuir para a reformulação dos serviços, considerando o contexto atual.