Planning for the future of maternal immunization: Building on lessons learned from the COVID-19 pandemic.

As the worldwide COVID-19 pandemic unfolded, the clinical and public health community raced to understand SARS-CoV-2 infection and develop life-saving vaccines. Pregnant persons were disproportionately impacted, experiencing more severe illness and adverse pregnancy outcomes. And yet, when COVID-19 vaccines became available in late 2020, safety and efficacy data were not available to inform their use during pregnancy because pregnant persons were excluded from pre-authorization clinical trials. Concerns about vaccine safety during pregnancy and misinformation linking vaccination and infertility circulated widely, creating a lack of vaccine confidence. Many pregnant people initially chose not to get vaccinated, and while vaccination rates rose after safety and effectiveness data became available, COVID-19 vaccine acceptance was suboptimal and varied across racial and ethnic distribution of the pregnant population. The COVID-19 pandemic experience provided valuable insights that can inform current and future approaches to maternal vaccination against.

Strengthening COVID-19 vaccine confidence & demand during the US COVID-19 emergency response.

In October 2020, the CDC's Vaccinate with Confidence strategy specific to COVID-19 vaccines rollout was published. Adapted from an existing vaccine confidence framework for childhood immunization, the Vaccinate with Confidence strategy for COVID-19 aimed to improve vaccine confidence, demand, and uptake of COVID-19 vaccines in the US. The objectives for COVID-19 were to 1. build trust, 2. empower healthcare personnel, and 3. engage communities and individuals. This strategy was implemented through a dedicated unit, the Vaccine Confidence and Demand (VCD) team, which collected behavioral insights; developed and disseminated toolkits and best practices in collaboration with partners; and collaborated with health departments and community-based organizations to engage communities and individuals in behavioral interventions to strengthen vaccine demand and increase COVID-19 vaccine uptake. The VCD team collected and used social and behavioral data through establishing the Insights Unit, implementing rapid community assessments, and conducting national surveys. To strengthen capacity at state and local levels, the VCD utilized "Bootcamps," a rapid training of trainers on vaccine confidence and demand, "Confidence Consults", where local leaders could request tailored advice to address local vaccine confidence challenges from subject matter experts, and utilized surge staffing to embed "Vaccine Demand Strategists" in state and local public health agencies. In addition, collaborations with Prevention Research Centers, the Institute of Museum and Library Services, and the American Psychological Association furthered work in behavioral science, community engagement, and health equity. The VCD team operationalized CDC's COVID-19 Vaccine with Confidence strategy through behavioral insights, capacity building opportunities, and collaborations to improve COVID-19 vaccine confidence, demand, and uptake in the US. The inclusion of applied behavioral science approaches were a critical component of the COVID-19 vaccination program and provides lessons learned for how behavioral science can be integrated in future emergency responses.

Pregnancy and infant outcomes following SARS-CoV-2 infection in pregnancy during delta variant predominance - Surveillance for Emerging Threats to Pregnant People and Infants.

BACKGROUND: SARS-CoV-2 infection in pregnancy is associated with an increased risk of adverse birth outcomes such as preterm birth, stillbirth, and maternal and infant complications. Previous research suggests an increased risk of severe COVID-19 illness and stillbirth in pregnant people during delta variant predominance in 2021; however, those studies did not assess timing of infection during pregnancy, and few of them described COVID-19 vaccination status. OBJECTIVE: Using a large population-based cohort, this study compared pregnancy and infant outcomes and described demographic and clinical characteristics of pregnant people with SARS-CoV-2 infection prior to and during the delta variant period. STUDY DESIGN: This retrospective cohort analysis included persons with confirmed SARS-CoV-2 infection in pregnancy from 6 US jurisdictions reporting to the Surveillance for Emerging Threats to Pregnant People and Infants Network. Data were collected through case reports of polymerase chain reaction-positive pregnant persons and linkages to birth certificates, fetal death records, and immunization records. We described clinical characteristics and compared frequency of spontaneous abortion (<20 weeks of gestation), stillbirth (≥20 weeks), preterm birth (<37 weeks), small for gestational age, and term infant neonatal intensive care unit admission between the time periods of pre-delta and delta variant predominance. Study time periods were determined by when variants constituted more than 50% of sequences isolated according to regional SARS-CoV-2 genomic surveillance data, with time periods defined for pre-delta (March 3, 2020-June 25, 2021) and Delta (June 26, 2021-December 25, 2021). Adjusted prevalence ratios were estimated for each outcome measure using Poisson regression and were adjusted for continuous maternal age, race and ethnicity, and insurance status at delivery. RESULTS: Among 57,563 pregnancy outcomes, 57,188 (99.3%) were liveborn infants, 65 (0.1%) were spontaneous abortions, and 310 (0.5%) were stillbirths. Most pregnant persons were unvaccinated at the time of SARS-CoV-2 infection, with a higher proportion in pre-delta (99.4%) than in the delta period (78.4%). Of those with infections during delta and who were previously vaccinated, the timing from last vaccination to infection was a median of 183 days. Compared to pre-delta, infections during delta were associated with a higher frequency of stillbirths (0.7% vs 0.4%; adjusted prevalence ratio, 1.55; 95% confidence interval, 1.14-2.09) and preterm births (12.8% vs 11.9%; adjusted prevalence ratio, 1.14; 95% confidence interval, 1.07-1.20). The delta period was associated with a lower frequency of neonatal intensive care unit admission (adjusted prevalence ratio, 0.74; 95% confidence interval, 0.67-0.82) than in the pre-delta period. During the delta period, infection during the third trimester was associated with a higher frequency of preterm birth (adjusted prevalence ratio, 1.41; 95% confidence interval, 1.28-1.56) and neonatal intensive care unit admission (adjusted prevalence ratio, 1.21; 95% confidence interval, 1.01-1.45) compared to the first and second trimester combined. CONCLUSION: In this US-based cohort of persons with SARS-CoV-2 infection in pregnancy, the majority were unvaccinated, and frequencies of stillbirth and preterm birth were higher during the delta variant predominance period than in the pre-delta period. During the delta period, frequency of preterm birth and neonatal intensive care unit admission was higher among infections occurring in the third trimester vs those earlier in pregnancy. These findings demonstrate population-level increases of adverse fetal and infant outcomes, specifically in the presence of a COVID-19 variant with more severe presentation.

Development of COVID-19 vaccine policy - United States, 2020-2023.

COVID-19 vaccines represent a great scientific and public health achievement in the face of overwhelming pressures from a global pandemic, preventing millions of hospitalizations and deaths due to COVID-19 vaccines in the United States. Over 675 million doses of COVID-19 vaccines have been administered in the United States, and over 80% of the U.S. population has had at least 1 dose of a COVID-19 vaccine. Over the course of the COVID-19 pandemic in the United States, over one million people died from COVID-19, and over six million were hospitalized. It has been estimated that COVID-19 vaccines prevented more than 18 million additional hospitalizations and more than 3 million additional deaths due to COVID-19 in the United States. From the beginning of the COVID-19 pandemic in 2020 through June 2023, ACIP had 35 COVID-19 focused meetings and 24 votes for COVID-19 vaccine recommendations. ACIP had the critical task of rapidly and thoroughly reviewing emerging and evolving data on COVID-19 epidemiology and vaccines, as well as making comprehensive population-based recommendations for vaccine policy and considerations for implementation through a transparent and evidence-based framework. Safe and effective COVID-19 vaccines, recommended through transparent policy discussions with ACIP, remain the best tool we have to prevent serious illness, hospitalization and death from COVID-19.