Safety of COVID-19 vaccines, their components or their platforms for pregnant women: A rapid review

BACKGROUND

Pregnant women with COVID-19 are at an increased risk of severe COVID-19 illness as well as adverse pregnancy and birth outcomes. Many countries are vaccinating or considering vaccinating pregnant women with limited available data about the safety of this strategy. Early identification of safety concerns of COVID-19 vaccines, including their components, or their technological platforms is therefore urgently needed.

METHODS

We conducted a rapid systematic review, as the first phase of an ongoing full systematic review, to evaluate the safety of COVID-19 vaccines in pregnant women, including their components, and their technological platforms (whole virus, protein, viral vector or nucleic acid) used in other vaccines, following the Cochrane methods and the PRISMA statement for reporting (PROSPERO-CRD42021234185).We searched literature databases, COVID-19 and pregnancy registries from inception February 2021 without time or language restriction and explored the reference lists of relevant systematic reviews retrieved. We selected studies of any methodological design that included at least 50 pregnant women or pregnant animals exposed to the vaccines that were selected for review by the COVAX MIWG in August 2020 or their components or platforms included in the COVID-19 vaccines, and evaluated adverse events during pregnancy and the neonatal period.Pairs of reviewers independently selected studies through the COVIDENCE web software and performed the data extraction through a previously piloted online extraction form. Discrepancies were resolved by consensus.

RESULTS

We identified 6768 records, 256 potentially eligible studies were assessed by full-text, and 37 clinical and non-clinical studies (38 reports, involving 2,397,715 pregnant women and 56 pregnant animals) and 12 pregnancy registries were included.Most studies (89%) were conducted in high-income countries. The most frequent study design was cohort studies (n=21), followed by surveillance studies, randomized controlled trials, and registry analyses. Most studies (76%) allowed comparisons between vaccinated and unvaccinated pregnant women (n=25) or animals (n=3) and reported exposures during the three trimesters of pregnancy.The most frequent exposure was to AS03 adjuvant in the context of A/H1N1 pandemic influenza vaccines (n=24), followed by aluminum-based adjuvants (n=11). Aluminum phosphate was used in Respiratory Syncytial Virus Fusion candidate vaccines (n=3) and Tdap vaccines (n=3). Different aluminum-based adjuvants were used in hepatitis vaccines. The replication-deficient simian adenovirus ChAdOx1 was used for a Rift Valley fever vaccine. Only one study reported exposure to messenger RNA (mRNA) COVID-19 vaccines that also used lipid nanoparticles. Except for one preliminary report about A/H1N1 influenza vaccination (adjuvant AS03) - corrected by the authors in a more thorough analysis, all studies concluded that there were no safety concerns.

CONCLUSION

This rapid review found no evidence of pregnancy-associated safety concerns of COVID-19 vaccines that were selected for review by the COVAX MIWG or of their components or platforms when used in other vaccines. However, the need for further data on several vaccine platforms and components is warranted given their novelty. Our findings support current WHO guidelines recommending that pregnant women may consider receiving COVID-19 vaccines, particularly if they are at high risk of exposure or have comorbidities that enhance the risk of severe disease.

The pediatric solid organ transplant experience with COVID-19: An initial multi-center, multi-organ case series

The clinical course of COVID-19 in pediatric solid organ transplant recipients remains ambiguous. Though preliminary experiences with adult transplant recipients have been published, literature centered on the pediatric population is limited. We herein report a multi-center, multi-organ cohort analysis of COVID-19-positive transplant recipients ≤ 18 years at time of transplant. Data were collected via institutions' respective electronic medical record systems. Local review boards approved this cross-institutional study. Among 5 transplant centers, 26 patients (62% male) were reviewed with a median age of 8 years. Six were heart recipients, 8 kidney, 10 liver, and 2 lung. Presenting symptoms included cough (n = 12 (46%)), fever (n = 9 (35%)), dry/sore throat (n = 3 (12%)), rhinorrhea (n = 3 (12%)), anosmia (n = 2 (8%)), chest pain (n = 2 (8%)), diarrhea (n = 2 (8%)), dyspnea (n = 1 (4%)), and headache (n = 1 (4%)). Six patients (23%) were asymptomatic. No patient required supplemental oxygen, intubation, or ECMO. Eight patients (31%) were hospitalized at time of diagnosis, 3 of whom were already admitted for unrelated problems. Post-transplant immunosuppression was reduced for only 2 patients (8%). All symptomatic patients recovered within 7 days. Our multi-institutional experience suggests the prognoses of pediatric transplant recipients infected with COVID-19 may mirror those of immunocompetent children, with infrequent hospitalization and minimal treatment, if any, required.

Sensitive and Prolonged Detection of Dengue Virus RNA in Whole Blood

Molecular detection of dengue virus (DENV) RNA from serum or plasma provides an accurate acute-phase diagnostic (< 7 days after symptom onset). Detection may be prolonged in whole blood, although data are limited. We tested for DENV by real-time reverse transcription-PCR in 345 paired acute-phase plasma and whole blood samples from individuals with a Flavivirus-like illness in southwestern Guatemala. In 18/18 cases with detectable DENV RNA in plasma, whole blood samples were positive and yielded similar cycle threshold values. In seven individuals with convalescent samples obtained 2-3 weeks later, DENV RNA remained detectable in whole blood but not plasma. In three additional cases, DENV RNA was only detectable in whole blood at the acute visit. In two cases, whole blood detection was linked to a virologically confirmed DENV infection 6-11 weeks earlier. Whole blood DENV RNA detection is sensitive for acute dengue infection and may remain positive for weeks to months.

Efficacy and safety of influenza vaccination during pregnancy: realizing the potential of maternal influenza immunization

Introduction: Pregnant women are at higher risk of severe complications following influenza infection compared to the general population. Influenza vaccination during pregnancy can offer direct protection to pregnant women and passive immunity to infants up to 6 months of age via maternal antibodies. Pregnant women are a high priority group for influenza immunization.Areas covered: This review provides an overview of the basis for recommending influenza vaccine to pregnant women, current immunization policies, the evidence supporting the safety and effectiveness of maternal vaccination, and future research needed. We conducted a search of PubMed for articles describing the safety or efficacy of influenza vaccines administered during pregnancy. Published articles from inception to 17 November 2020 were reviewed.Expert opinion: Experimental and observational evidence support the efficacy, effectiveness and safety of influenza immunization during pregnancy. These data support the continued provision of inactivated influenza vaccine to pregnant women, as recommended by global immunization policies. To achieve success with maternal influenza immunization programs, further work is needed to inform policy development in low- and middle-income settings and implementation and promotion in high-income settings.

Infections Within the First Month After Pediatric Lung Transplantation: Epidemiology and Impact on Outcomes

BACKGROUND

Despite successes in lung transplantation, with infection as the leading cause of death in the first year following lung transplantation, there remains a lag in survival compared with other solid organ transplants. Infections that occur early after transplantation may impact short- and long-term outcomes in pediatric lung transplant recipients (LTRs).

METHODS

We performed a retrospective review of pediatric LTRs at a large quaternary-care hospital from January 2009 to March 2016 to evaluate both epidemiologic features of infection in the first 30 days post-transplantation and mortality outcomes. The 30 days were divided into early (0-7 days) and late (8-30 days) periods.

RESULTS

Among the 98 LTRs, there were 51 episodes of infections. Cystic fibrosis (CF) was associated with early bacterial infections (P = .004) while non-CF was associated with late viral (P = .02) infections. Infection after transplantation was associated with worse survival by Kaplan-Meier analysis (P value log rank test = .007). Viral infection in the late period was significantly associated with 3-year mortality after multivariable analysis (P = .02).

CONCLUSIONS

Infections in pediatric LTRs were frequent in the first 30 days after transplant, despite perioperative antimicrobial coverage. The association of 3-year mortality with late viral infections suggests a possible important role in post-transplant lung physiology and graft function. Understanding the epidemiology of early post-lung transplant infections can help guide post-operative management and interventions to reduce their incidence and the early- and long-term impact in this population.

Vaccine-associated enhanced disease: Case definition and guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration Case Definition of the term “Vaccine Associated Enhanced Disease” to be utilized in the evaluation of adverse events following immunization. The Case Definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2 vaccines and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected Expert Reviewers prior to submission.

Parent Report of Health Related Quality of Life in Young Children in Rural Guatemala: Implementation, Reliability, and Validity of the PedsQL in Stunting and Wasting

In this study, we review the implementation, reliability, and validity of the Pediatric Quality of Life Inventory (PedsQL), a measure of health-related quality of life, in young children in rural Guatemala. Mothers of 842 children (age range = 1-60 months) completed the PedsQL Generic Core Scales 4.0 serially for 1 year. Low (Pearson’s r = 0.28, P < .0001) to moderate (Pearson’s r = 0.65, P < .0001) consistency in responding over time was shown. The PedsQL did not discriminate reliably between healthy children and those with stunting or wasting. PedsQL scores were not lower during the time of an acute illness. While we found low to moderate evidence for the reliability of the PedsQL in healthy children, it did not discriminate between healthy children and those with stunting, wasting or other acute illness.

Vaccines and routine immunization strategies during the COVID-19 pandemic

Severe acute respiratory syndrome coronavirus 2 related disease (COVID-19) is now responsible for one of the most challenging and concerning pandemics. By August 2020, there were almost 20 million confirmed cases worldwide and well over half-million deaths. Since there is still no effective treatment or vaccine, non-pharmaceutical interventions have been implemented in an attempt to contain the spread of the virus. During times of quarantine, immunization practices in all age groups, especially routine childhood vaccines, have also been interrupted, delayed, re-organized, or completely suspended. Numerous high-income as well as low- and middle-income countries are now experiencing a rapid decline in childhood immunization coverage rates. We will, inevitably, see serious consequences related to suboptimal control of vaccine-preventable diseases (VPDs) in children concurrent with or following the pandemic. Routine pediatric immunizations of individual children at clinics, mass vaccination campaigns, and surveillance for VPDs must continue as much as possible during pandemic.

Acute respiratory distress syndrome (ARDS) as an adverse event following immunization: Case definition & guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration Case Definition of the term “Acute Respiratory Distress Syndrome – ARDS” to be utilized in the evaluation of adverse events following immunization. The Case Definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for SARS-CoV-2 vaccines and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and defined levels of certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network and by selected Expert Reviewers prior to submission. The comments of the reviewers were taken into consideration and edits incorporated in this final manuscript.

The Fifth International Neonatal and Maternal Immunization Symposium (INMIS 2019): Securing Protection for the Next Generation

Despite significant progress in reaching some milestones of the United Nations Sustainable Development Goals, neonatal and early infant morbidity and mortality remain high, and maternal health remains suboptimal in many countries. Novel and improved preventative strategies with the potential to benefit pregnant women and their infants are needed, with maternal and neonatal immunization representing effective approaches. Experts from immunology, vaccinology, infectious diseases, clinicians, industry, public health, and vaccine-related social sciences convened at the 5th International Neonatal and Maternal Immunization Symposium (INMIS) in Vancouver, Canada, from 15 to 17 September 2019. We critically evaluated the lessons learned from recent clinical studies, presented cutting-edge scientific progress in maternal and neonatal immunology and vaccine development, and discussed maternal and neonatal immunization in the broader context of infectious disease epidemiology and public health. Focusing on practical aspects of research and implementation, we also discussed the safety, awareness, and perception of maternal immunization as an existing strategy to address the need to improve maternal and neonatal health worldwide. The symposium provided a comprehensive scientific and practical primer as well as an update for all those with an interest in maternal and neonatal infection, immunity, and vaccination. The summary presented here provides an update of the current status of progress in maternal and neonatal immunization.

Human Herpesvirus 6 Infection in Pediatric Liver Transplantation: Single-Center Study of Incidence, Outcomes, and Management

BACKGROUND

Distinctions between HHV-6 primary infection in seronegative patients and HHV-6 reactivation in seropositive patients remains largely undescribed in pediatric liver transplant (LT) recipients.

METHODS

We implemented pretransplant serology testing of HHV-6 in a large pediatric hospital and retrospectively assessed the incidence, manifestations and outcomes of HHV-6 infections over a 3-year period.

RESULTS

Among 101 pediatric LT recipients, 96 had pretransplant HHV-6 serologies; 34 (35.4%) were seronegative and 62 (64.6%) seropositive. Posttransplantation, 8/25 (32%) seronegative patients had HHV-6 DNAemia (primary infection) compared to 2/48 (4%) seropositive patients (p=0.002). Compared to seropositive patients, seronegative patients with HHV-6 DNAemia were younger, and had symptoms of fever and/or elevated aminotransferases in association with higher viral loads, in the first month post-transplant. More than 90% of seronegative patients and 77.8% of seropositive patients had HHV-6 detected by PCR in liver biopsy obtained for concerns of allograft rejection, but most had no detectable concomitant DNAemia. Active replication of virus in the liver was confirmed by in situ hybridization in select cases. While HHV-6 infection occurred among patients on prophylaxis doses of antivirals for CMV, HHV-6 DNAemia and presenting symptoms resolved on treatment doses.

CONCLUSIONS

HHV-6 DNA-emia occurred more frequently in seronegative pediatric LT recipients, usually in the early posttransplant period, and was subsequently detected in allograft biopsies. HHV-6 cannot be ruled out as a cause of hepatitis in the absence of allograft tissue testing and specialized virological assays, as HHV-6 may disrupt local allograft immune homeostasis while evading traditional screening methods using blood or plasma. The assessment of pre-transplant HHV-6 serological status may be important for risk stratification and post-transplant management of pediatric LT recipients.

757. Association between cumulative febrile, respiratory and diarrheal illness in the first year of life and neurodevelopmental and growth outcomes among a cohort of children in rural Guatemala

Background

Recurrent infections are associated with neurodevelopmental (ND) delay in infants, but the primary drivers are poorly understood. Leveraging an infant cohort from rural Guatemala designed to evaluate the effects of post-natal Zika virus on ND (DMID 16-0057), we evaluated the association between cumulative illness and ND delay and stunting.

Methods

Infants enrolled at 0-3 months of age underwent weekly at-home surveillance for caregiver-reported syndromic illness, including cough, fever and vomiting/diarrhea for a 12-month period. Anthropometric assessments and ND testing by Guatemalan psychologists using the Mullen Scales of Early Learning (MSEL) were perforrmed at 12-15 months of age. Multivariable generalized linear regression models were used to test associations between syndromic illness in infancy, 12-15-month MSEL Early Learning Composite (ELC) Score, and stunting (height-for-age &lt; -2 SD) at 12-15 months.

Results

The cohort (n=425) had a mean enrollment age of 1.3 months; 202 (48%) were female, 387 (91%) self-reported a literate mother, and 301 (71%) were breastfeeding at study completion. Infants had reported illness for a median of 16 weeks during the surveillance period; cough was reported most frequently (median=11 weeks, range=0-37 weeks). Lower maternal education (p=0.007) and literacy (p=0.002) as well as infant age (p=0.007) and male gender (p=0.004) were associated with MSEL ELC Score &lt;85 (-1 SD). After adjusting for gender, breastfeeding, age, and maternal literacy, the cumulative number of weeks with reported cough (p=0.0009), fever (p=0.0001), or any syndromic illness (p=0.0007) were associated with decreased 12-month MSEL ECL Score; there was no association with diarrhea/vomiting (p=0.36). There was no association between caregiver-reported syndromic illnesses (any type) and stunting at final study visit.

Conclusion

In a cohort of Guatemalan infants, cumulative fever and cough episodes were significantly associated with lower MSEL ELC Score, whereas there was no association with diarrhea/vomiting. In this low-resource community, these findings highlight the potential negative ND consequences of febrile illness and persistent cough in the first year of life. NIAID Contract HHSN272201300015I Task Order HHSN27200013 (Co-PIs: FMM and EJA).

Disclosures

Molly Lamb, PhD, BioFire (Grant/Research Support) Evan J. Anderson, MD, Sanofi Pasteur (Scientific Research Study Investigator)

1084. Epidemiology and Long-term Outcomes of Cytomegalovirus (CMV) in Pediatric Liver Transplant Recipients (PLTR) at Texas Children’s Hospital (TCH)

Background

Despite widespread use of prevention strategies, CMV DNAemia remains common in PLTR. Contemporary data, however, is limited. We sought to determine the frequency of, risk factors for, and long term outcomes of CMV DNAemia in a large, single center cohort of PLTR.

Methods

A retrospective cohort study of PLTR < 22 yrs of age transplanted from 2011-2018 was completed. Per protocol, CMV prophylaxis with ganciclovir/valganciclovir was universally implemented; high risk (HR)(D+/R-) and intermediate risk (IR)(R+) patients received 6 months while low risk (LR)(D-/R-) patients received 3 months. Primary outcomes included any CMV DNAemia, CMV DNAemia >1000 IU/mL and long term outcomes including rejection, graft failure, hepatic steatosis (HS), and de novo autoimmune hepatitis (AIH). Associations with CMV DNAemia were measured using Fisher exact and multivariate regression. Survival analysis, time to CMV infection, and time to PLTR long term outcomes were assessed using Kaplan-Meier plots.

Results

Among 270 PLTR, 81 (30%) had quantifiable CMV DNAemia; 36 (13%) had CMV DNAemia >1000 IU/mL. Fifty (19%) developed CMV DNAemia while on prophylaxis. Median time (range) to CMV DNAemia was 162 days (5-2213). HR (OR 4.18; 95% CI 1.84-9.49, p< 0.01) status was associated with CMV DNAemia and time to CMV DNAemia. CMV DNAemia was not associated with age at transplantation or cold ischemic time.

Eight PLTR (3%) developed CMV syndrome (4 HR, 3 IR, 1 LR), the median peak (range) DNAemia was 2133 IU/mL (202-58000) for these patients. No PLTR developed CMV tissue invasive disease.

CMV DNAemia was not associated with rejection (15% vs. 33%, p=0.62), graft failure (7% vs. 13%, p=0.17), HS (8% vs. 12%, p=0.32), or AIH (10% vs. 8%, p= 0.68). CMV DNAemia was associated with a longer time to rejection (p=0.02). Time to development of graft failure, HS, and AIH were not associated with CMV DNAemia (Figure 1). Finally, there was no difference in survival during the study follow-up period (1 – 9 yrs) for PLTR with vs. without CMV DNAemia (p=0.58).

Figure 1

Conclusion

This large cohort of PLTR demonstrates high rates of CMV DNAemia but low rates of CMV disease. HR status remains associated with CMV DNAemia. CMV DNAemia did not increase the risk of long term adverse outcomes such as rejection, graft failure, HS, and AIH.

Disclosures

All Authors: No reported disclosures

1407. Cytomegalovirus (CMV) infection in the first year of life in a cohort of infants in rural Guatemala

Background

Little is known about the epidemiology of Cytomegalovirus (CMV) infection in low resource countries. We evaluated the frequency and effects of post-natal CMV infection in infants from a prospective cohort study designed to assess the effects of post-natal Zika on neurodevelopment (ND) in rural Guatemala.

Infants with CMV infection (blue bars) were older compared CMV-negative (red bars) infants.

Methods

Infants were evaluated for CMV infection by PCR using urine samples collected at 0-3 months of age. ND testing was conducted by local psychologists using a culturally adapted Mullen Scales of Early Learning (MSEL). We explored associations between CMV infection and microcephaly, neurological, visual and hearing deficits, malnutrition and ND outcomes at 1 year of age.

Results

The infant cohort (N = 469) had a mean age at enrollment of 1.5 (SD 0.75) months; 47% were female and 71% were breastfeeding at 1 year. A total of 103 (22%) were CMV positive and the majority of these (97%) were > 4 weeks of age at testing. Infants > 4 weeks of age were more likely to be CMV positive (P < 0.0001) (Figure). Gender was not correlated with CMV positivity. Among children with head circumference (HC) measurements, microcephaly (HC < 2 SD) was present in 9/87 (10.3%) CMV positive and 35/338 (10.4%) CMV negative infants at 0-3 months of age (p =0.99). Among 438 infants who underwent screening for hearing deficits and a complete ophthalmologic evaluation, none of the CMV positive children had abnormal vision or hearing. Abnormal neurological exams in the first year of life occurred in 50/100 (50%) CMV positive and 166/365 (45.5%) CMV negative infants (p =0.56). There was no association between CMV infection at 0-3 months and MSEL overall or subdomain scores at 1 year (overall Relative risk (RR) 1.02, 95% CI 0.99-1.05, p=0.16). Malnutrition at 0-3 months (RR: 1.53, 95% CI 0.89-2.66, p = 0.13) and 1 year (RR: 1.10, 95% CI 0.77-1.58, p=0.59) was not associated with CMV infection at 0-3 months.

Conclusion

In a cohort of Guatemalan infants, postnatal CMV infection was common (22%) and more likely to occur after the neonatal period. There was no correlation between CMV infection and microcephaly at 0-3 months or at 1 year of age, nor with abnormal nutritional, neurologic, ophthalmologic, hearing or ND deficits at 1 year of age. This is the first epidemiologic report on CMV infection in early life in rural Guatemala.

Disclosures

Molly Lamb, PhD, BioFire (Grant/Research Support)

Suptavumab for the Prevention of Medically Attended Respiratory Syncytial Virus Infection in Preterm Infants

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of childhood medically attended respiratory infection (MARI).

METHODS

We conducted a randomized, double-blind, placebo-controlled phase 3 trial in 1154 preterm infants of 1 or 2 doses of suptavumab, a human monoclonal antibody that can bind and block a conserved epitope on RSV A and B subtypes, for the prevention of RSV MARI. The primary endpoint was proportion of subjects with RSV-confirmed hospitalizations or outpatient lower respiratory tract infection (LRTI).

RESULTS

There were no significant differences between primary endpoint rates (8.1%, placebo; 7.7%, 1-dose; 9.3%, 2-dose). Suptavumab prevented RSV A infections (relative risks, .38; 95% confidence interval [CI], .14-1.05 in the 1-dose group and .39 [95% CI, .14-1.07] in the 2-dose group; nominal significance of combined suptavumab group vs placebo; P = .0499), while increasing the rate of RSV B infections (relative risk 1.36 [95% CI, .73-2.56] in the 1-dose group and 1.69 [95% CI, .92-3.08] in the 2-dose group; nominal significance of combined suptavumab group vs placebo; P = .12). Sequenced RSV isolates demonstrated no suptavumab epitope changes in RSV A isolates, while all RSV B isolates had 2-amino acid substitution in the suptavumab epitope that led to loss of neutralization activity. Treatment emergent adverse events were balanced across treatment groups.

CONCLUSIONS

Suptavumab did not reduce overall RSV hospitalizations or outpatient LRTI because of a newly circulating mutant strain of RSV B. Genetic variation in circulating RSV strains will continue to challenge prevention efforts.

CLINICAL TRIALS REGISTRATION

NCT02325791. https://clinicaltrials.gov/ct2/show/NCT02325791.

Respiratory Syncytial Virus Vaccination during Pregnancy and Effects in Infants

BACKGROUND

Respiratory syncytial virus (RSV) is the dominant cause of severe lower respiratory tract infection in infants, with the most severe cases concentrated among younger infants.

METHODS

Healthy pregnant women, at 28 weeks 0 days through 36 weeks 0 days of gestation, with an expected delivery date near the start of the RSV season, were randomly assigned in an overall ratio of approximately 2:1 to receive a single intramuscular dose of RSV fusion (F) protein nanoparticle vaccine or placebo. Infants were followed for 180 days to assess outcomes related to lower respiratory tract infection and for 364 days to assess safety. The primary end point was RSV-associated, medically significant lower respiratory tract infection up to 90 days of life, and the primary analysis of vaccine efficacy against the primary end point was performed in the per-protocol population of infants (prespecified criterion for success, lower bound of the 97.52% confidence interval [CI] of ≥30%).

RESULTS

A total of 4636 women underwent randomization, and there were 4579 live births. During the first 90 days of life, the percentage of infants with RSV-associated, medically significant lower respiratory tract infection was 1.5% in the vaccine group and 2.4% in the placebo group (vaccine efficacy, 39.4%; 97.52% CI, -1.0 to 63.7; 95% CI, 5.3 to 61.2). The corresponding percentages for RSV-associated lower respiratory tract infection with severe hypoxemia were 0.5% and 1.0% (vaccine efficacy, 48.3%; 95% CI, -8.2 to 75.3), and the percentages for hospitalization for RSV-associated lower respiratory tract infection were 2.1% and 3.7% (vaccine efficacy, 44.4%; 95% CI, 19.6 to 61.5). Local injection-site reactions among the women were more common with vaccine than with placebo (40.7% vs. 9.9%), but the percentages of participants who had other adverse events were similar in the two groups.

CONCLUSIONS

RSV F protein nanoparticle vaccination in pregnant women did not meet the prespecified success criterion for efficacy against RSV-associated, medically significant lower respiratory tract infection in infants up to 90 days of life. The suggestion of a possible benefit with respect to other end-point events involving RSV-associated respiratory disease in infants warrants further study. (Funded by Novavax and the Bill and Melinda Gates Foundation; ClinicalTrials.gov NCT02624947.).

Safety and immunogenicity of three seasonal inactivated influenza vaccines among pregnant women and antibody persistence in their infants

OBJECTIVE

Inactivated influenza virus vaccines (IIVs) are recommended for all pregnant women in the United States. We conducted a prospective, randomized, double blind study of three licensed seasonal trivalent IIVs (IIV3s) to assess their safety and immunogenicity in pregnant women and determine the level and persistence of passively transferred maternal antibody in infants.

STUDY DESIGN

139 pregnant women ages 18-39 years and 14-33 weeks' gestation, and 44 non-pregnant women, were randomized 1:1:1 to receive a single intramuscular dose of one of three licensed IIV3s (Agriflu®, Fluzone®, or Fluarix®) prior to the 2010-2011 influenza season. Reactogenicity, adverse events (AEs) and pregnancy outcomes were documented. Serum samples for hemagglutination inhibition (HAI) and neutralization antibody assays were collected prior to and 28 and 180 days after immunization. Maternal sera and cord blood were collected at the time of delivery and sera were obtained from 44 infants at 6 weeks of age.

RESULTS

Pregnant and non-pregnant women experienced similar frequency of injection site (92% and 86%, respectively) and systemic (95% and 87%, respectively) reactions, the majority of which were mild. There were no vaccine-associated maternal or infant serious AEs. Antibody responses to the three vaccine antigens were not different between pregnant and non-pregnant women. The ratios of cord blood (infant) to maternal HAI antibody titers at delivery ranged between 1.1 and 1.7 for each of the vaccine antigens. Influenza antibody concentrations in infants were 70-40% of the birth titer by 6 weeks of age.

CONCLUSIONS

The three IIV3s were well tolerated in pregnant women. Antibody responses were comparable in pregnant and non-pregnant women, and after second or third trimester vaccination. Transplacental transfer of maternal antibodies to the infant was efficient. However, antibody titers decline rapidly in the first 6 weeks of life.

Respiratory Syncytial Virus-Associated Hospitalizations Among Young Children: 2015-2016

BACKGROUND

Respiratory syncytial virus (RSV) is a major cause of hospitalized acute respiratory illness (ARI) among young children. With RSV vaccines and immunoprophylaxis agents in clinical development, we sought to update estimates of US pediatric RSV hospitalization burden.

METHODS

Children <5 years old hospitalized for ARI were enrolled through active, prospective, population-based surveillance from November 1, 2015, to June 30, 2016, at 7 US pediatric hospital sites. Clinical information was obtained from parent interviews and medical records. Midturbinate nasal and throat flocked swabs were collected and tested for RSV by using molecular diagnostic assays at each site. We conducted descriptive analyses and calculated population-based rates of RSV-associated hospitalizations.

RESULTS

Among 2969 hospitalized children included in analyses, 1043 (35%) tested RSV-positive; 903 (87%) children who were RSV-positive were <2 years old, and 526 (50%) were <6 months old. RSV-associated hospitalization rates were 2.9 per 1000 children <5 years old and 14.7 per 1000 children <6 months old; the highest age-specific rate was observed in 1-month-old infants (25.1 per 1000). Most children who were infected with RSV (67%) had no underlying comorbid conditions and no history of preterm birth.

CONCLUSIONS

During the 2015-2016 season, RSV infection was associated with one-third of ARI hospitalizations in our study population of young children. Hospitalization rates were highest in infants <6 months. Most children who were RSV-positive had no history of prematurity or underlying medical conditions, suggesting that all young children could benefit from targeted interventions against RSV.

Coronavirus Disease 2019 in Children Cared for at Texas Children's Hospital: Initial Clinical Characteristics and Outcomes

We describe the clinical course of 57 children with coronavirus disease 2019 (COVID-19) cared for through a single hospital system. Most children were mildly symptomatic, and only a few patients with underlying medical conditions required hospitalization. Systemwide patient evaluation processes allowed for prompt identification and management of patients with COVID-19.

Infectious and Autoimmune Causes of Encephalitis in Children

BACKGROUND AND OBJECTIVES

Encephalitis can result in neurologic morbidity and mortality in children. Newly recognized infectious and noninfectious causes of encephalitis have become increasingly important over the past decade.

METHODS

We retrospectively reviewed medical records from pediatric patients in Houston diagnosed with encephalitis in both an urban and rural catchment area between 2010 and 2017. We conducted an investigation to understand the etiology, clinical characteristics, and diagnostic testing practices in this population.

RESULTS

We evaluated 231 patients who met the case definition of encephalitis, among which 42% had no recognized etiology. Among those with an identified etiology, the most common were infectious (73; 31%), including viral (n = 51; 22%), with the most frequent being West Nile virus (WNV; n = 12), and bacterial (n = 19; 8%), with the most frequent being Bartonella henselae (n = 7). Among cases of autoimmune encephalitis (n = 60; 26%), the most frequent cause was anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis (n = 31). Autoimmune causes were seen more commonly in female (P < .01) patients. Testing for herpes simplex virus and enterovirus was nearly universal; testing for anti-NMDAR encephalitis, WNV, and Bartonella was less common.

CONCLUSIONS

WNV was the most common infectious cause of encephalitis in our pediatric population despite lower testing frequency for WNV than herpes simplex virus or enterovirus. Increasing testing for anti-NMDAR encephalitis resulted in frequent identification of cases. Increased awareness and testing for WNV and Bartonella would likely result in more identified causes of pediatric encephalitis. Earlier etiologic diagnosis of encephalitides may lead to improve clinical outcomes.

Sensorineural hearing loss (SNHL) as an adverse event following immunization (AEFI): Case definition & guidelines for data collection, analysis, and presentation of immunization safety data

This is a Brighton Collaboration case definition of the term "Sensorineural Hearing Loss" to be utilized in the evaluation of adverse events following immunization. The case definition was developed by a group of experts convened by the Coalition for Epidemic Preparedness Innovations (CEPI) in the context of active development of vaccines for Lassa Fever and other emerging pathogens. The case definition format of the Brighton Collaboration was followed to develop a consensus definition and define levels of diagnostic certainty, after an exhaustive review of the literature and expert consultation. The document underwent peer review by the Brighton Collaboration Network.

Obstetrics risk Assessment: Evaluation of selection criteria for vaccine research studies in pregnant women

Vaccines designed for use in pregnancy and vaccine trials specifically involving pregnant women are rapidly expanding. One of the key challenges in designing maternal immunization trials is that developing exclusion criteria requires understanding and quantifying the background risk for adverse pregnancy outcomes in the pregnancy being studied, which can occur independent of any intervention and be unrelated to vaccine administration. The Global Alignment of Immunization Safety Assessment in Pregnancy (GAIA) project has developed and published case definitions and guidelines for data collection, analysis, and evaluation of maternal immunization safety in trials involving pregnant women. Complementing this work, we sought to understand how to best assess obstetric risk of adverse outcomes and differentiate it from the assessment of vaccine safety. Quantification of obstetric risk is based on prior and current obstetric, and maternal medical history. We developed a step-wise approach to evaluate and quantify obstetric and maternal risk factors in pregnancy based on review of published literature and guidelines, and critically assessed these factors in the context of designing inclusion and exclusion criteria for maternal vaccine studies. We anticipate this risk assessment evaluation may assist clinical trialists with study design decisions, including selection of exclusion criteria for vaccine trials involving pregnant women, consideration of sub-group classification, such as high or low risk subjects, or schedule considerations, such as preferred trimester of gestation for an intervention during pregnancy. Additionally, this tool may be utilized in data stratification at time of study analyses.