Respiratory Syncytial Virus-Associated Hospitalizations Among Children <5 Years Old: 2016 to 2020

BACKGROUND

Respiratory syncytial virus (RSV) is the leading cause of hospitalization in US infants. Accurate estimates of severe RSV disease inform policy decisions for RSV prevention.

METHODS

We conducted prospective surveillance for children <5 years old with acute respiratory illness from 2016 to 2020 at 7 pediatric hospitals. We interviewed parents, reviewed medical records, and tested midturbinate nasal ± throat swabs by reverse transcription polymerase chain reaction for RSV and other respiratory viruses. We describe characteristics of children hospitalized with RSV, risk factors for ICU admission, and estimate RSV-associated hospitalization rates.

RESULTS

Among 13 524 acute respiratory illness inpatients <5 years old, 4243 (31.4%) were RSV-positive; 2751 (64.8%) of RSV-positive children had no underlying condition or history of prematurity. The average annual RSV-associated hospitalization rate was 4.0 (95% confidence interval [CI]: 3.8-4.1) per 1000 children <5 years, was highest among children 0 to 2 months old (23.8 [95% CI: 22.5-25.2] per 1000) and decreased with increasing age. Higher RSV-associated hospitalization rates were found in premature versus term children (rate ratio = 1.95 [95% CI: 1.76-2.11]). Risk factors for ICU admission among RSV-positive inpatients included: age 0 to 2 and 3 to 5 months (adjusted odds ratio [aOR] = 1.97 [95% CI: 1.54-2.52] and aOR = 1.56 [95% CI: 1.18-2.06], respectively, compared with 24-59 months), prematurity (aOR = 1.32 [95% CI: 1.08-1.60]) and comorbid conditions (aOR = 1.35 [95% CI: 1.10-1.66]).

CONCLUSIONS

Younger infants and premature children experienced the highest rates of RSV-associated hospitalization and had increased risk of ICU admission. RSV prevention products are needed to reduce RSV-associated morbidity in young infants.

Seasonality, clinical characteristics, and outcomes of respiratory syncytial virus disease by subtype among children less than five years old, New Vaccine Surveillance Network, United States, 2016-2020

BACKGROUND

Respiratory syncytial virus (RSV) is a leading cause of acute respiratory illnesses (ARI) in children. RSV can be broadly categorized into two major subtypes (A and B). RSV subtypes have been known to co-circulate with variability in different regions of the world. Clinical associations with viral subtype have been studied among children with conflicting findings such that no conclusive relationships between RSV subtype and severity have been established.

METHODS

During 2016-2020, children <5 years old were enrolled in prospective surveillance in the emergency department (ED) or inpatient (IP) settings from seven U.S. pediatric medical centers. Surveillance data collection included parent/guardian interviews, chart reviews, and collection of mid-turbinate nasal +/- throat swabs for RSV (RSV-A, RSV-B, and Untyped) by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Among 6398 RSV-positive children <5 years old, 3424 (54%) had subtype RSV-A infections, 2602 (41%) had subtype RSV-B infections, and 272 (5%) were not typed, inconclusive, or mixed infections. In both adjusted and unadjusted analyses, RSV-A-positive children were more likely to be hospitalized, as well as when restricted to <1 year. By season, RSV-A and RSV-B co-circulated in varying levels, with one subtype dominating proportionally.

CONCLUSION

Findings indicate that RSV-A and RSV-B may only be marginally clinically distinguishable but both subtypes are associated with medically attended illness in children <5 years old. Furthermore, circulation of RSV subtypes varies substantially each year, seasonally and geographically. With introduction of new RSV prevention products, this highlights the importance of continued monitoring of RSV-A and RSV-B subtypes.

Effectiveness of Pfizer-BioNTech COVID-19 vaccine as evidence for policy action: A rapid systematic review and meta-analysis of non-randomized studies

In December 2020, an interim recommendation for the use of Pfizer-BioNTech COVID-19 vaccine in persons aged ≥16 years was made under Food and Drug Administration's Emergency Use Authorization. In preparation for Biologics License Application approval, we conducted a systematic review and meta-analysis to inform the U.S. Centers for Disease Control and Prevention's Advisory Committee for Immunization Practice's (ACIP) decision-making for a standard recommendation. We conducted a rapid systematic review and meta-analysis of Pfizer-BioNTech vaccine effectiveness (VE) against symptomatic COVID-19, hospitalization due to COVID-19, death due to COVID-19, and asymptomatic SARS-CoV-2 infection. We identified studies through August 20, 2021 from an ongoing systematic review conducted by the International Vaccine Access Center and the World Health Organization. We evaluated each study for risk of bias using the Newcastle-Ottawa Scale. Pooled estimates were calculated using meta-analysis. The body of evidence for each outcome was assessed using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. We identified 80 articles, selected 35 for full-text review, and included 26. The pooled VE of Pfizer-BioNTech COVID-19 vaccine was 92.4% (95% CI: 87.5%-95.3%) against symptomatic COVID-19 with moderate evidence certainty (eight studies), 94.3% (95% CI: 87.9%-97.3%) against hospitalization due to COVID-19 with moderate certainty (eight studies), 96.1% (95% CI: 91.5%-98.2%) against death due to COVID-19 with moderate certainty (four studies), and 89.3% (88.4%-90.1%) against asymptomatic SARS-CoV-2 infection with very low certainty (two studies). The Pfizer-BioNTech COVID-19 vaccine demonstrated high effectiveness in all pre-specified outcomes and extended knowledge of the vaccine's benefits to outcomes and populations not informed by the RCTs. Use of an existing systematic review facilitated a rapid meta-analysis to inform an ACIP policy decision. This approach can be utilized as additional COVID-19 vaccines are considered for standard recommendations by ACIP.

The Advisory Committee on Immunization Practices' Interim Recommendations for Additional Primary and Booster Doses of COVID-19 Vaccines - United States, 2021

Three COVID-19 vaccines are currently approved under a Biologics License Application (BLA) or authorized under an Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA) and recommended for primary vaccination by the Advisory Committee on Immunization Practices (ACIP) in the United States: the 2-dose mRNA-based Pfizer-BioNTech/Comirnaty and Moderna COVID-19 vaccines and the single-dose adenovirus vector-based Janssen (Johnson & Johnson) COVID-19 vaccine (1,2) (Box 1). In August 2021, FDA amended the EUAs for the two mRNA COVID-19 vaccines to allow for an additional primary dose in certain immunocompromised recipients of an initial mRNA COVID-19 vaccination series (1). During September-October 2021, FDA amended the EUAs to allow for a COVID-19 vaccine booster dose following a primary mRNA COVID-19 vaccination series in certain recipients aged ≥18 years who are at increased risk for serious complications of COVID-19 or exposure to SARS-CoV-2 (the virus that causes COVID-19), as well as in recipients aged ≥18 years of Janssen COVID-19 vaccine (1) (Table). For the purposes of these recommendations, an additional primary (hereafter additional) dose refers to a dose of vaccine administered to persons who likely did not mount a protective immune response after initial vaccination. A booster dose refers to a dose of vaccine administered to enhance or restore protection by the primary vaccination, which might have waned over time. Health care professionals play a critical role in COVID-19 vaccination efforts, including for primary, additional, and booster vaccination, particularly to protect patients who are at increased risk for severe illness and death.

Use of Pfizer-BioNTech COVID-19 Vaccine in Persons Aged ≥16 Years: Recommendations of the Advisory Committee on Immunization Practices - United States, September 2021

The Pfizer-BioNTech COVID-19 vaccine (BNT162b2) is a lipid nanoparticle-formulated, nucleoside mRNA vaccine encoding the prefusion spike glycoprotein of SARS-CoV-2, the virus that causes COVID-19. Vaccination with the Pfizer-BioNTech COVID-19 vaccine consists of 2 intramuscular doses (30 μg, 0.3 mL each) administered 3 weeks apart. In December 2020, the vaccine was granted Emergency Use Authorization (EUA) by the Food and Drug Administration (FDA) as well as an interim recommendation for use among persons aged ≥16 years by the Advisory Committee on Immunization Practices (ACIP) (1). In May 2021, the EUA and interim ACIP recommendations for Pfizer-BioNTech COVID-19 vaccine were extended to adolescents aged 12-15 years (2). During December 14, 2020-September 1, 2021, approximately 211 million doses of Pfizer-BioNTech COVID-19 vaccine were administered in the United States.* On August 23, 2021, FDA approved a Biologics License Application for use of the Pfizer-BioNTech COVID-19 vaccine, Comirnaty (Pfizer, Inc.), in persons aged ≥16 years (3). The ACIP COVID-19 Vaccines Work Group's conclusions regarding the evidence for the Pfizer-BioNTech COVID-19 vaccine were presented to ACIP at a public meeting on August 30, 2021. To guide its deliberations regarding the Pfizer-BioNTech COVID-19 vaccine, ACIP used the Evidence to Recommendation (EtR) Framework,† and incorporated a Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.§ In addition to initial clinical trial data, ACIP considered new information gathered in the 8 months since issuance of the interim recommendation for Pfizer-BioNTech COVID-19 vaccine, including additional follow-up time in the clinical trial, real-world vaccine effectiveness studies, and postauthorization vaccine safety monitoring. The additional information increased certainty that benefits from prevention of asymptomatic infection, COVID-19, and associated hospitalization and death outweighs vaccine-associated risks. On August 30, 2021, ACIP issued a recommendation¶ for use of the Pfizer-BioNTech COVID-19 vaccine in persons aged ≥16 years for the prevention of COVID-19.

Case Report: Chorioamnionitis Attributed to Streptococcus thoraltensis

Streptococcus thoraltensis is a recently described species, isolated from the intestinal and genital tracts of swine and from rabbit feces. We describe here a case of chorioamnionitis, with paternal swine exposure, potentially attributable to S. thoraltensis. To our knowledge, this is the first reported human infection by this organism.

Tobacco use among South Dakotans

Tobacco use is the leading cause of preventable deaths in the United States and in South Dakota. Reducing tobacco use among South Dakotans is critical to alleviate the heavy burden of preventable deaths, illnesses and excessive health care costs that result from using tobacco products. The South Dakota Department of Health's Tobacco Control Program has collaborated with various agencies and coalitions to discourage people from starting to smoke, to help current smokers quit and to protect all people from exposure to secondhand smoke. The South Dakota Behavioral Risk Factor Surveillance System (BRFSS), the South Dakota Youth Tobacco Survey (YTS), the South Dakota Youth Risk Behavior Survey (YRBS), South Dakota Vital Statistics and the South Dakota Perinatal Health Risk Assessment Survey are the primary instruments used to measure progress toward achieving the goals and objectives of South Dakota's tobacco control effort. Since 2001, the South Dakota Department of Health's Tobacco Control Program has been implementing comprehensive statewide programs to reduce tobacco use and exposure to secondhand smoke. Concurrent with the comprehensive tobacco control program implementation, the prevalence of cigarette smoking declined significantly from its peak of 27.2 percent in 1998 to its current low of 19.8 percent in 2007, which is equal to the national average of 19.8 percent. Use of spit tobacco among adult South Dakotans also has declined from 6.8 percent in 2003 to 5.8 percent in 2007. There also has been a reduction in the number of high school students that are current smokers, i.e., having smoked cigarettes on one or more of the past 30 days, from 33 percent in 2001 to 25 percent in 2007.2 The prevalence of current smokers among middle school-aged South Dakotans has decreased from 8 percent in 2005 to 6 percent in 2007. Important shifts have occurred in the struggle to quit smoking: In South Dakota, 57.2 percent of current smokers are trying to quit. In addition, 80.8 percent of respondents report that smoking is not allowed in any work area. Positive changes have taken place in South Dakotans' attitudes toward exposure to secondhand smoke. There is widespread awareness of the harm of secondhand smoke, with 83 percent of respondents indicating that they believed secondhand smoke causes lung cancer. These positive trends across a multitude of indicators suggest that the comprehensive tobacco control effort in South Dakota is having an effect in reducing the harms of tobacco. The decreases in smoking prevalence among South Dakota adults and youth are some of the most encouraging findings. However, challenges remain. The tobacco industry is well aware of efforts to reduce tobacco use and continues to develop and promote new products. Despite decreasing cigarette use among all adults in South Dakota, 18- to 24-year-olds still have the highest smoking rate, at 29.3 percent. Surveillance will continue to monitor tobacco use trends in South Dakota and assess the impact of tobacco control efforts. Some of the most important findings are summarized in the following report.