Predictors of the Outcome at 2 Years in Neonates With Congenital Cytomegalovirus Infection.

BACKGROUND: Approximately 20% of neonates with congenital cytomegalovirus (cCMV) develop long-term sequelae. The ability to accurately predict long-term outcomes as early as the neonatal period would help to provide for appropriate parental counseling and treatment indications. With this study, we aimed to identify neonatal predictive markers of cCMV long-term outcomes. METHODS: As this study's subjects, we chose neonates diagnosed with cCMV in 13 hospitals throughout France recruited from 2013 to 2017 and evaluated for at least 2 years with thorough clinical, audiology, and imaging evaluations and psychomotor development tests. RESULTS: A total of 253 neonates were included, and 3 were later excluded because of the identification of a genetic disorder. A total of 227 were followed up for 2 years: 187/227 (82%) and 34/227 (15%) were infected after a maternal primary or nonprimary infection, respectively, 91/227 (40%) were symptomatic at birth, and 44/227 (19%) had cCMV sequelae. Maternal primary infection in the first trimester was the strongest prognosis factor (odds ratio = 38.34 [95% confidence interval, 5.02-293], P < .001). A predictive model of no risk of sequelae at 2 years of age according to normal hearing loss at birth, normal cerebral ultrasound, and normal platelet count had 98% specificity, 69% sensitivity, and 0.89 area under the curve (95% confidence interval, 0.83-0.96). CONCLUSIONS: In the studied population, children with normal hearing at birth, normal platelet count at birth, and a normal cranial ultrasound had no risk of neurologic sequelae and a low risk of delayed unilateral sensorineural hearing loss. The use of this model based on readily available neonatal markers should help clinicians establish a personalized care pathway for each cCMV neonate.

Nirsevimab for Prevention of Hospitalizations Due to RSV in Infants.

BACKGROUND: The safety of the monoclonal antibody nirsevimab and the effect of nirsevimab on hospitalizations for respiratory syncytial virus (RSV)-associated lower respiratory tract infection when administered in healthy infants are unclear. METHODS: In a pragmatic trial, we randomly assigned, in a 1:1 ratio, infants who were 12 months of age or younger, had been born at a gestational age of at least 29 weeks, and were entering their first RSV season in France, Germany, or the United Kingdom to receive either a single intramuscular injection of nirsevimab or standard care (no intervention) before or during the RSV season. The primary end point was hospitalization for RSV-associated lower respiratory tract infection, defined as hospital admission and an RSV-positive test result. A key secondary end point was very severe RSV-associated lower respiratory tract infection, defined as hospitalization for RSV-associated lower respiratory tract infection with an oxygen saturation of less than 90% and the need for supplemental oxygen. RESULTS: A total of 8058 infants were randomly assigned to receive nirsevimab (4037 infants) or standard care (4021 infants). Eleven infants (0.3%) in the nirsevimab group and 60 (1.5%) in the standard-care group were hospitalized for RSV-associated lower respiratory tract infection, which corresponded to a nirsevimab efficacy of 83.2% (95% confidence interval [CI], 67.8 to 92.0; P<0.001). Very severe RSV-associated lower respiratory tract infection occurred in 5 infants (0.1%) in the nirsevimab group and in 19 (0.5%) in the standard-care group, which represented a nirsevimab efficacy of 75.7% (95% CI, 32.8 to 92.9; P = 0.004). The efficacy of nirsevimab against hospitalization for RSV-associated lower respiratory tract infection was 89.6% (adjusted 95% CI, 58.8 to 98.7; multiplicity-adjusted P<0.001) in France, 74.2% (adjusted 95% CI, 27.9 to 92.5; multiplicity-adjusted P = 0.006) in Germany, and 83.4% (adjusted 95% CI, 34.3 to 97.6; multiplicity-adjusted P = 0.003) in the United Kingdom. Treatment-related adverse events occurred in 86 infants (2.1%) in the nirsevimab group. CONCLUSIONS: Nirsevimab protected infants against hospitalization for RSV-associated lower respiratory tract infection and against very severe RSV-associated lower respiratory tract infection in conditions that approximated real-world settings. (Funded by Sanofi and AstraZeneca; HARMONIE ClinicalTrials.gov number, NCT05437510).

Antibiotic therapy for osteoarticular infections in 2023: Proposals from the Pediatric Infectious Pathology Group (GPIP).

Most osteoarticular infections (OAI) occur via the hematogenous route, affect children under 5 years of age old, and include osteomyelitis, septic arthritis, osteoarthritis and spondylodiscitis. Early diagnosis and prompt treatment are needed to avoid complications. Children with suspected OAI should be hospitalized at the start of therapy. Surgical drainage is indicated in patients with septic arthritis or periosteal abscess. Staphylococcus aureus is implicated in OAI in children at all ages; Kingella kingae is a very common causative pathogen in children from 6 months to 4 years old. The French Pediatric Infectious Disease Group recommends empirical antibiotic therapy with appropriate coverage against methicillin-sensitive S. aureus (MSSA) with high doses (150 mg/kg/d) of intravenous cefazolin. In most children presenting uncomplicated OAI with favorable outcome (disappearance of fever and pain), short intravenous antibiotic therapy during 3 days can be followed by oral therapy. In the absence of bacteriological identification, oral relay is carried out with the amoxicillin/clavulanate combination (80 mg/kg/d of amoxicillin) or cefalexin (150 mg/kg/d). If the bacterial species is identified, antibiotic therapy will be adapted to antibiotic susceptibility. The minimum total duration of antibiotic therapy should be 14 days for septic arthritis, 3 weeks for osteomyelitis and 4-6 weeks for OAI of the pelvis, spondylodiscitis and more severe OAI, and those evolving slowly under treatment or with an underlying medical condition (neonate, infant under 3 months of old, immunocompromised patients). Treatment of spondylodiscitis and severe OAI requires systematic orthopedic advice.

Severe and fatal neonatal infections linked to a new variant of echovirus 11, France, July 2022 to April 2023.

We report nine severe neonatal infections caused by a new variant of echovirus 11. All were male, eight were twins. At illness onset, they were 3-5 days-old and had severe sepsis and liver failure. This new variant, detected in France since April 2022, is still circulating and has caused more fatal neonatal enterovirus infections in 2022 and 2023 (8/496; 1.6%, seven associated with echovirus 11) compared with 2016 to 2021 (7/1,774; 0.4%). National and international alerts are warranted.

Clinical Value of Serial Quantitative Analysis of Cytomegalovirus DNA in Blood and Saliva Over the First 24 Months of Life in Congenital Infection: The French Cymepedia Cohort.

OBJECTIVE: To evaluate cytomegalovirus (CMV) viral load dynamics in blood and saliva during the first 2 years of life in symptomatic and asymptomatic infected infants and to identify whether these kinetics could have practical clinical implications. STUDY DESIGN: The Cymepedia cohort prospectively included 256 congenitally infected neonates followed for 2 years. Whole blood and saliva were collected at inclusion and months 4 and 12, and saliva at months 18 and 24. Real-time CMV polymerase chain reaction (PCR) was performed, results expressed as log10 IU/mL in blood and in copies per milliliter in saliva. RESULTS: Viral load in saliva progressively decreased from 7.5 log10 at birth to 3.3 log10 at month 24. CMV PCR in saliva was positive in 100% and 96% of infants at 6 and 12 months, respectively. In the first month of life, neonatal saliva viral load of less than 5 log10 was related to a late CMV transplacental passage. Detection in blood was positive in 92% of neonates (147/159) in the first month of life. No viral load threshold values in blood or saliva could be associated with a high risk of sequelae. Neonatal blood viral load of less than 3 log10 IU/mL had a 100% negative predictive value for long-term sequelae. CONCLUSIONS: Viral loads in blood and saliva by CMV PCR testing in congenital infection fall over the first 24 months. In this study of infants affected mainly after primary maternal infection during pregnancy, all salivary samples were positive in the first 6 months of life and sequelae were not seen in infants with neonatal blood viral load of less than 3 log10 IU/mL.

Preventing Respiratory Syncytial Virus in Children in France: A Narrative Review of the Importance of a Reinforced Partnership Between Parents, Healthcare Professionals, and Public Health Authorities.

The highly contagious respiratory syncytial virus (RSV) is responsible for up to approximately 50,000 hospitalisations during each RSV season in children aged under 5 years in France, with the burden greatest in infants younger than 1 year who were born at term. There is a need for a strategy to universally protect young children from RSV infection, and thereby reduce the pressure that RSV places every year on RSV-infected children, their parents, and French healthcare systems. Potential strategies currently undergoing clinical investigation include passive immunisation via maternal vaccination or administration of long-acting monoclonal antibodies at or soon after birth, followed by vaccination later in infancy or childhood. An ongoing partnership and collaboration between parents, public health authorities, and frontline primary healthcare will need to be reinforced once these new RSV prevention strategies are available, to facilitate their use and ensure that all children receive adequate protection from the start of their first RSV season.

Overview of meningococcal epidemiology and national immunization programs in children and adolescents in 8 Western European countries.

Background: In Europe, meningococcal (Men) vaccines are available against 5 of the 6 serogroups responsible of nearly all cases of invasive meningococcal disease (IMD). Meningococcal vaccination has been introduced in the national immunization programs (NIPs) for children and adolescents of numerous European countries, but with no consistent strategy across countries. Objectives: To describe IMD epidemiology, NIPs, and vaccination coverage rates (VCRs) in children and adolescents in 8 Western European countries. Methods: Epidemiological data (from 1999 to 2019), NIPs regarding meningococcal vaccination status, and VCRs were collected from the European Centre for Disease Prevention and Control (ECDC) and/or national websites. Results: MenB was the most common serogroup. In Belgium, Spain, France, the Netherlands, the United Kingdom (UK), and Portugal, incidence was greater for MenW than MenC. In 2019, MenB risk was covered in 2 countries (Italy, UK). MenC risk was covered in all countries, via MenC only (countries: N = 3), MenACWY only (N = 2), or MenC (infants/children) and MenACWY (adolescents) (N = 3) vaccination. VCRs were higher in children than adolescents. Conclusion: Our study confirmed the diversity of NIPs, including in neighboring European countries with similar factors like economic resources and epidemiological risk, thus indicating that other factors underlie NIPs. Convergence toward a more common immunization program including MenACWY and MenB vaccination would promote equity and safe travel regarding infectious diseases for young people, and possibly improve the understanding of vaccination by patients and healthcare professionals.

Relay oral therapy in febrile urinary tract infections caused by extended spectrum beta-lactamase-producing Enterobacteriaceae in children: A French multicenter study.

OBJECTIVES: We need studies assessing therapeutic options for oral relay in febrile urinary tract infection (FUTI) due to ESBL-producing Enterobacteriaceae (ESBL-E) in children. Amoxicillin-clavulanate/cefixime (AC-cefixime) combination seems to be a suitable option. We sought to describe the risk of recurrence at 1 month after the end of treatment for FUTI due to ESBL-E according to the oral relay therapy used. MATERIALS AND METHODS: We retrospectively identified children <18 years who were included in a previous prospective observational multicentric study on managing FUTI due to ESBL-E between 2014 and 2017 in France. We collected whether children who received cotrimoxazole, ciprofloxacin or the AC-cefixime combination as the oral relay therapy reported a recurrence within the first month after the end of treatment. Then, we analyzed the susceptibility drug-testing of the strains involved. RESULTS: We included 199 children who received an oral relay therapy with cotrimoxazole (n = 72, 36.2%), ciprofloxacin (n = 38, 19.1%) or the AC-cefixime combination (n = 89, 44.7%). Nine (4.5%) patients had a recurrence within the first month after the end of treatment, with no difference between the 3 groups of oral relay (p = 0.8): 4 (5.6%) cotrimoxazole, 2 (5.3%) ciprofloxacin and 3 (3.4%) AC-cefixime combination. Phenotype characterization of 249 strains responsible for FUTI due to ESBL-E showed that 97.6% were susceptible to the AC-cefixime combination. CONCLUSIONS: The AC-cefixime combination represents an interesting therapeutic option for oral relay treatment of FUTI due to ESBL-E as the recurrence rate at 1 month after the end of treatment was the same when compared to cotrimoxazole and ciprofloxacin.

Clavulanate combinations with mecillinam, cefixime or cefpodoxime against ESBL-producing Enterobacterales frequently associated with blaOXA-1 in a paediatric population with febrile urinary tract infections.

OBJECTIVES: Oral treatment of febrile urinary tract infections (FUTIs) can be impaired by MDR Enterobacterales often combining ESBL and inhibitor-resistant genes. We studied the impact of ß-lactamases and Enterobacterales' genotypes on the cefixime, cefpodoxime and mecillinam ± amoxicillin/clavulanate MICs. MATERIALS AND METHODS: In this multicentric study, we included 251 previously whole-genome-sequenced ESBL-producing Enterobacterales, isolated in French children with FUTIs. The MICs of cefixime, cefpodoxime, mecillinam alone and combined with amoxicillin/clavulanate were determined and analysed with respect to genomic data. We focused especially on the isolates' ST and their type of ß-lactamases. Clinical outcomes of patients who received cefixime + amoxicillin/clavulanate were also analysed. RESULTS: All isolates were cefixime and cefpodoxime resistant. Disparities depending on blaCTX-M variants were observed for cefixime. The addition of amoxicillin/clavulanate restored susceptibility for cefixime and cefpodoxime in 97.2% (MIC50/90 of 0.38/0.75 mg/L) and 55.4% (MIC50/90 of 1/2 mg/L) of isolates, respectively, whatever the ST, the blaCTX-M variants or the association with inhibitor-resistant ß-lactamases (34.2%). All isolates were susceptible to mecillinam + amoxicillin/clavulanate with MIC50/90 of 0.19/0.25 mg/L, respectively. Neither therapeutic failure nor any subsequent positive control urine culture were reported for patients who received cefixime + amoxicillin/clavulanate as an oral relay therapy (n = 54). CONCLUSIONS: Despite the frequent association of ESBL genes with inhibitor-resistant ß-lactamases, the cefixime + amoxicillin/clavulanate MICs remain low. The in vivo efficacy of this combination was satisfying even when first-line treatment was ineffective. Considering the MIC distributions and pharmacokinetic parameters, mecillinam + amoxicillin/clavulanate should also be an alternative to consider when treating FUTIs in children.

Malignant pertussis in infants: factors associated with mortality in a multicenter cohort study.

BACKGROUND: Malignant pertussis (MP) affects young infants and is characterized by respiratory distress, perpetual tachycardia and hyperleukocytosis up to 50 G/l, leading to multiple organ failure and death in 75% of cases. Leukodepletion may improve prognosis. A therapeutic strategy based on leukodepletion and extracorporeal life support (ECLS) according to different thresholds of leucocytes has been proposed by Rowlands and colleagues. We aimed at identifying factors associated with death and assess whether the respect of the Rowlands' strategy is associated with survival. METHODS: We reviewed all MP infants hospitalized in eight French pediatric intensive care units from January 2008 to November 2013. All infants younger than 3 months of age, admitted for respiratory distress with a diagnosis of pertussis and WBC count ≥ 50 G/l were recorded. Evolution of WBC was analyzed and an optimal threshold for WBC growth was obtained using the ROC-curve method. Clinical and biological characteristics of survivors and non-survivors were compared. Therapeutic management (leukodepletion and/or ECLS) was retrospectively assessed for compliance with Rowlands' algorithm (indication and timing of specific treatments). RESULTS: Twenty-three infants were included. Nine of 23 (40%) died: they presented more frequently cardiovascular failure (100% vs 36%, p = 0.003) and pulmonary hypertension (PHT; 100% vs 29%, p = 0.002) than survivors and the median [IQR] WBC growth was significantly faster among them (21.3 [9.7-28] G/l/day vs 5.9 [3.0-6.8] G/l/day, p = 0.007). WBC growth rate > 12 G/l/day and lymphocyte/neutrophil ratio < 1 were significantly associated with death (p = 0.001 and p = 0.003, respectively). Ten infants (43%) underwent leukodepletion, and seven (30%) underwent ECLS. Management following Rowlands' strategy was associated with survival (100% vs 0%; p < 0.001, relative risk of death = 0.18, 95%-CI [0.05-0.64]). CONCLUSIONS: A fast leukocyte growth and leukocytosis with neutrophil predominance during acute pertussis infection were associated with death. These findings should prompt clinicians to closely monitor white blood cells in order to early identify infants at risk of fatal outcome during the course of malignant pertussis. Such an early signal in infants at high risk of death would increase feasibility of compliant care to Rowlands' strategy, with the expectation of a better survival.

SARS-CoV-2 transmission among children and staff in daycare centres during a nationwide lockdown in France: a cross-sectional, multicentre, seroprevalence study.

BACKGROUND: The extent to which very young children contribute to the transmission of SARS-CoV-2 is unclear. We aimed to estimate the seroprevalence of antibodies against SARS-CoV-2 in daycare centres that remained open for key workers' children during a nationwide lockdown in France. METHODS: Children and staff who attended one of 22 daycare centres during a nationwide lockdown in France (between March 15 and May 9, 2020) were included in this cross-sectional, multicentre, seroprevalence study. Hospital staff not occupationally exposed to patients with COVID-19, or to children, were enrolled in a comparator group. The primary outcome was SARS-CoV-2 seroprevalence in children, daycare centre staff, and the comparator group. The presence of antibodies against SARS-CoV-2 in capillary whole blood was measured with a rapid chromatographic immunoassay. We computed raw prevalence as the percentage of individuals with a positive IgG or IgM test, and used Bayesian smoothing to account for imperfect sensitivity and specificity of the assay. This study is registered with ClinicalTrials.gov, NCT04413968. FINDINGS: Between June 4 and July 3, 2020, we enrolled 327 children (mean age 1·9 [SD 0·9] years; range 5 months to 4·4 years), 197 daycare centre staff (mean age 40 [12] years), and 164 adults in the comparator group (42 [12] years). Positive serological tests were observed for 14 children (raw seroprevalence 4·3%; 95% CI 2·6-7·1) and 14 daycare centre staff (7·7%; 4·2-11·6). After accounting for imperfect sensitivity and specificity of the assay, we estimated that 3·7% (95% credible interval [95% CrI] 1·3-6·8) of the children and 6·8% (3·2-11·5) of daycare centre staff had SARS-CoV-2 infection. The comparator group fared similarly to the daycare centre staff; nine participants had a positive serological test (raw seroprevalence 5·5%; 95% CI 2·9-10·1), leading to a seroprevalence of 5·0% (95% CrI 1·6-9·8) after accounting for assay characteristics. An exploratory analysis suggested that seropositive children were more likely than seronegative children to have been exposed to an adult household member with laboratory-confirmed COVID-19 (six [43%] of 14 vs 19 [6%] of 307; relative risk 7·1 [95% CI 2·2-22·4]). INTERPRETATION: According to serological test results, the proportion of young children in our sample with SARS-CoV-2 infection was low. Intrafamily transmission seemed more plausible than transmission within daycare centres. Further epidemiological studies are needed to confirm this exploratory hypothesis. FUNDING: Assistance Publique-Hôpitaux de Paris; Mairie de Paris, Conseil Départemental de Seine Saint Denis. TRANSLATIONS: For the French translation of the abstract see Supplementary Materials section.

Diversity and trends in population structure of ESBL-producing Enterobacteriaceae in febrile urinary tract infections in children in France from 2014 to 2017.

BACKGROUND: The population structure of extraintestinal pathogenic Escherichia coli evolves over time, notably due to the emergence of antibiotic-resistant clones such as ESBL-producing Enterobacteriaceae (ESBL-E). OBJECTIVES: To analyse by WGS the genetic diversity of a large number of ESBL-E isolated from urinary tract infections in children from paediatric centres across France between 2014 and 2017 and collected by the National Observatory of febrile urinary tract infection (FUTI) caused by ESBL-E. METHODS: A total of 40 905 Enterobacteriaceae-positive urine cultures were identified. ESBL-E were found in 1983 samples (4.85%). WGS was performed on 251 ESBL-E causing FUTI. STs, core genome MLST (cgMLST), serotype, fimH allele, ESBL genes and presence of papGII key virulence factor were determined. RESULTS: E. coli and Klebsiella pneumoniae were found in 86.9% (218/251) and 11.2% (28/251) of cases, respectively. Several STs predominate among E. coli such as ST131, ST38, ST69, ST73, ST95, ST405, ST12 and ST1193, while no ST emerged in K. pneumoniae. E. coli ST131, ST38 and ST1193 increased during the study period, with a heterogeneity in papGII prevalence (64.5%, 35% and 20% respectively). Most isolates harboured the CTX-M type (97%) with a predominance of blaCTX-M-15. blaCTX-M-27, an emerging variant in E. coli, is found in various STs. cgMLST enabled discrimination of clusters within the main STs. CONCLUSIONS: The predominance of ST131, and the emergence of other STs such as ST38 and ST1193 combined with ESBL genes deserves close epidemiological surveillance considering their high threat in infectious disease. cgMLST could be a discriminant complementary tool for the analyses.

Educational and health outcomes associated with bronchopulmonary dysplasia in 15-year-olds born preterm.

INTRODUCTION: To evaluate the consequences of bronchopulmonary dysplasia (BPD) on academic outcomes and healthcare use in adolescents born very preterm. METHODS: This cohort study included 15-year-old adolescents born very preterm (< 32 weeks) between 2011 and 2013, with and without BPD, and controls born full term. Data regarding academic performance, current medical follow-up, and family characteristics were collected. Multivariate logistic regression was used to quantify relationships between academic outcomes and BPD. RESULTS: From the 1341 children included in the initial cohort, 985 adolescents were eligible and 351 included (55 preterms with a history of BPD, 249 without, and 47 controls). Among adolescents born very preterm, a history of BPD was associated with a higher risk to attend a school for children with special needs (p < 0.05) and to have repeated a grade (p = 0.01). It was also associated with an increased number of medical and paramedical consultations. A history of BPD was not associated with the parents' employment status, family structure, or the presence of younger siblings. CONCLUSION: This study highlights that a history of BPD is associated with poorer academic outcomes and high healthcare use in adolescence.

Sequelae of Congenital Cytomegalovirus Following Maternal Primary Infections Are Limited to Those Acquired in the First Trimester of Pregnancy.

BACKGROUND: The known relationship between the gestational age at maternal primary infection an the outcome of congenital CMV is based on small, retrospective studies conducted between 1980 and 2011. They reported that 32% and 15% of cases had sequelae following a maternal primary infection in the first and second or the third trimester, respectively. We aimed to revisit this relationship prospectively between 2011 and 2017, using accurate virological tools. METHODS: We collected data on women with a primary infection and an infected child aged at least 1 year at the time of analysis. An accurate determination of the timing of the primary infection was based upon serial measurements of immunoglobulin (Ig) M and IgG and on IgG avidity in sera collected at each trimester. The case outcome was assessed according to a structured follow-up between birth and 48 months. RESULTS: We included 255 women and their 260 fetuses/neonates. The dating of the maternal infection was prospective in 86% of cases and retrospective in 14%. At a median follow-up of 24 months, the proportion of sensorineural hearing loss and/or neurologic sequelae were 32.4% (95% confidence interval [CI] 23.72-42.09) after a maternal primary infection in the first trimester, 0 (95% CI 0-6.49) after an infection in the second trimester, and 0 (95% CI 0-11.95) after an infection in the third trimester (P < .0001). CONCLUSIONS: These results suggest that a cytomegalovirus infection can be severe only when the virus hits the fetus in the embryonic or early fetal period. Recent guidelines recommend auditory follow-ups for at least 5 years for all infected children. This raises parental anxiety and generates significant costs. We suggest that auditory and specialized neurologic follow-ups may be recommended only in cases of a maternal infection in the first trimester.

Association between asthma and lung function in adolescents born very preterm: results of the EPIPAGE cohort study.

Prematurity and bronchopulmonary dysplasia (BPD) affect long-term lung function. We studied the respiratory outcome of adolescents born very preterm and controls from the Etude EPIdémiologique sur les Petits Ages Gestationnels cohort and analysed their current lung function in relation to asthma symptoms (categorised in three age groups) from birth. In models including BPD, asthma at each age and confounding factors in the preterm group, BPD and preschool wheeze were the only independent variables associated with FEV1 Preschool wheeze is an independent factor associated with FEV1 impairment in adolescents born very preterm. These results highlight the need for optimal management of early respiratory symptoms in preterm-born infants. TRIAL REGISTRATION NUMBER: Results, NCT01424553.

Immunization of preterm infants.

Vaccinations of premature infants are often delayed despite being at an increased risk of contracting vaccine preventable diseases. This article reviews the current knowledge on the immune response to widely used vaccines, on the protection derived from routine immunization and on vaccine safety and tolerability in a population of preterm infants. Available data evaluating the immune response of preterm infants support early immunization without correction for gestational age. For a number of antigens, the antibody response to initial doses of vaccines may be lower than that of term infants, but protective concentrations are often achieved and memory successfully induced. Vaccines are immunogenic, safe and well tolerated in preterm infants. Preterm infants should be vaccinated using the same schedules as those usually recommended for full-term infants, with the exception of the hepatitis B vaccine, where additional doses should be administered in infants receiving the first dose during the first days of life if they weighed less than 2000 g because of a documented reduced immune response.