Palivizumab

We retrospectively collected data (gender, gestational age, birthweight, age and weight at admission, need for non-invasive or invasive respiratory support, need for intravenous infusion, need for enteral fasting) from the medical records of neonates and infants aged <3 months, admitted to the Neonatal Intensive Care Unit and Neonatal Sub-Intensive Care Unit of our hospital for bronchiolitis from October 2021 to March 2022. We calculated clinical severity scores (WBSS, KRS, and eventually GRSS for patients with RSV infection only) on admission clinical data. Table 1 shows the parameters of each score. The WBSS consists of four items (respiratory rate, general appearance, wheezing, retractions), each ranging from 0 to 3, except for the general condition, which is scored only 0 and 3, with a total from 0 to 12. The KRS is based on five signs (respiratory rate, general appearance, wheezing, retractions and skin color), each from 0 to 2, with a total from 0 to 10. The GRSS is calculated entering ten parameters (age, oxygen saturation, respiratory rate, general appearance, wheezing, rhales/ronchi, retractions, skin color, lethargy, and poor air movement) in an interactive tool (available at: https://rprc.urmc.rochester.edu/app/AsPIRES/RSV-GRSS/).
We excluded infants hospitalized only for apnoea and with any high-risk conditions for respiratory failure (congenital heart disease, neurologic disorders, and immunodeficiency), those qualified for palivizumab prophylaxis, and those with incomplete clinical data.
Infants were discharged 24 h after they no longer needed respiratory support and they achieved full enteral feeding again, and they no longer needed intravenous infusion.
The primary outcome was the need for respiratory support (either high-flow nasal cannula, nasal continuous positive airway pressure, or mechanical ventilation).
The secondary outcome was the length of hospital stay (days).

An AE was defined as an unexpected event after administration of palivizumab that may or may not have had a causal relationship with the drug. The degree of each AE was assessed as one of three levels: mild, moderate, or severe.
Qualitative content analysis was used for free-text data from the questionnaires. Content analysis is a research technique useful for exploring people’s experiences of particular phenomena, and its goal is to provide knowledge and understanding of the phenomena being studied [17 ]. The verbatim-transcribed text was read through several times for the researchers to obtain a sense of the whole (Phase 1), after which meaning units were identified (Phase 2). These meaning units were condensed into descriptions close to the text (Phase 3) and then into interpretations of the underlying meanings (Phase 4). The first, third, and fourth authors abstracted the condensed meaning units into subcategories (Phase 5) and unified them into categories (Phase 6).

Eligible participants were infants entering the immunization program with palivizumab during one RSV season. Participants were born prematurely or had a CHD. The immunization program followed the national guidelines for immunization with palivizumab, which is indicated for extremely preterm infants born before gestational week 27 during their first 2 years of life and full-term newborns with CHD [10 ].
Participants were randomly assigned to an intervention group (IG) receiving immunization at home or a control group (CG) receiving the immunization at an outpatient clinic or at a hospital (standard care). To avoid randomizing twins into different groups, the participants were grouped in families and sorted in alphabetical order. The first family was randomized to the IG based on a coin toss, the second to the CG, and the rest alternately to the IG or the CG. Infants with previous AEs related to vaccination or immunization were excluded.