COVID-19 Bivalent Booster Vaccination Coverage and Intent to Receive Booster Vaccination Among Adolescents and Adults - United States, November-December 2022

Effectiveness and durability of mRNA-1273 BA.4/BA.5 bivalent vaccine (mRNA-1273.222) against SARS-CoV-2 BA.4/BA.5 and XBB sublineages

Emerging SARS-CoV-2 sublineages continue to cause serious COVID-19 disease, but most individuals have not received any COVID-19 vaccine for >1 year. Assessment of long-term effectiveness of bivalent COVID-19 vaccines against circulating sublineages is important to inform the potential need for vaccination with updated vaccines. In this test-negative study at Kaiser Permanente Southern California, sequencing-confirmed BA.4/BA.5- or XBB-related SARS-CoV-2-positive cases (September 1, 2022 to June 30, 2023), were matched 1:3 to SARS-CoV-2-negative controls. We assessed mRNA-1273 bivalent relative (rVE) and absolute vaccine effectiveness (VE) compared to ≥2 or 0 doses of original monovalent vaccine, respectively. The rVE analysis included 20,966 cases and 62,898 controls. rVE (95%CI) against BA.4/BA.5 at 14-60 days and 121-180 days was 52.7% (46.9-57.8%) and 35.5% (-2.8-59.5%) for infection, and 59.3% (49.7-67.0%) and 33.2% (-28.2-68.0%) for Emergency Department/Urgent Care (ED/UC) encounters. For BA.4/BA.5-related hospitalizations, rVE was 71.3% (44.9-85.1%) and 52.0% (-1.2-77.3%) at 14-60 days and 61-120 days, respectively. rVE against XBB at 14-60 days and 121-180 days was 48.8% (33.4-60.7%) and -3.9% (-18.1-11.3%) for infection, 70.7% (52.4-82.0%) and 15.7% (-6.0-33.2%) for ED/UC encounters, and 87.9% (43.8-97.4%) and 57.1% (17.0-77.8%) for hospitalization. VE and subgroup analyses (age, immunocompromised status, previous SARS-CoV-2 infection) results were similar to rVE analyses. rVE of mRNA-1273 bivalent vaccine against BA.4/BA.5 and XBB infections, ED/UC encounters, and hospitalizations waned over time. Periodic revaccination with vaccines targeting emerging variants may be important in reducing COVID-19 morbidity and mortality.

Changes in general and COVID-19 vaccine hesitancy among U.S. adults from 2021 to 2022

INTRODUCTION

Understanding changes in vaccine hesitancy, overall and by sociodemographic characteristics, may highlight sub-populations for whom more intensive efforts are needed to increase vaccine uptake and confidence.

METHODS

We analyzed data using the CDC's Research and Development Survey (RANDS), a nationally representative survey of U.S. adults ≥18 years, collected from 17 May 2021-30 June 2021 (n = 5,458) and 3 November 2022-12 December 2022 (n = 6,821). We assessed changes in vaccine hesitancy, changes in vaccine attitudes and attitudes, and factors associated with hesitancy toward both vaccines in general and COVID-19 vaccines among a nationally representative sample of U.S. adults.

RESULTS

Although COVID-19 vaccination (≥1 dose) increased from 67.2% (2021) to 74.7% (2022), COVID-19 vaccine hesitancy increased from 40.7% to 44.6% during the same period. During the same period, hesitancy toward both COVID-19 vaccines and vaccines in general increased among those who were aged ≥65 years and who were non-Hispanic White. However, COVID-19 vaccine hesitancy decreased among non-Hispanic Black adults. Current or former smokers were more hesitant toward vaccines in general (aPR = 1.13, 95%CI: 1.03-1.24) and toward COVID-19 vaccines (aPR = 1.08, 95%CI: 1.01-1.16) compared to never smokers. Among adults who did not receive any COVID-19 vaccines, COVID-19 vaccine hesitancy increased from 86.6% in 2021 to 92.4% in 2022. Furthermore, belief in the overall social benefit of the COVID-19 vaccine decreased from 47.5% to 25.1%.

CONCLUSION

This study highlights concerning trends in vaccine hesitancy and uptake of the COVID-19 and other recommended vaccines. We found that some high-risk groups (e.g. smokers) and population subgroups have become more vaccine hesitant, suggesting the need for improved and intensified strategies to increase vaccine confidence and uptake. Future research may focus on qualitative inquiry to understand specific concerns and determinants contributing to increased hesitancy among these groups to help inform interventions and communication campaigns to support vaccination.

Canadian health care providers' and education workers' hesitance to receive original and bivalent COVID-19 vaccines

BACKGROUND

The demand for COVID-19 vaccines has diminished as the pandemic lingers. Understanding vaccine hesitancy among essential workers is important in reducing the impact of future pandemics by providing effective immunization programs delivered expeditiously.

METHOD

Two surveys exploring COVID-19 vaccine acceptance in 2021 and 2022 were conducted in cohorts of health care providers (HCP) and education workers participating in prospective studies of COVID-19 illnesses and vaccine uptake. Demographic factors and opinions about vaccines (monovalent and bivalent) and public health measures were collected in these self-reported surveys. Modified multivariable Poisson regression was used to determine factors associated with hesitancy.

RESULTS

In 2021, 3 % of 2061 HCP and 6 % of 3417 education workers reported hesitancy (p < 0.001). In December 2022, 21 % of 868 HCP and 24 % of 1457 education workers reported being hesitant to receive a bivalent vaccine (p = 0.09). Hesitance to be vaccinated with the monovalent vaccines was associated with earlier date of survey completion, later receipt of first COVID-19 vaccine dose, no influenza vaccination, and less worry about becoming ill with COVID-19. Factors associated with hesitance to be vaccinated with a bivalent vaccine that were common to both cohorts were receipt of two or fewer previous COVID-19 doses and lower certainty that the vaccines were safe and effective.

CONCLUSION

Education workers were somewhat more likely than HCP to report being hesitant to receive COVID-19 vaccines but reasons for hesitancy were similar. Hesitancy was associated with non-receipt of previous vaccines (i.e., previous behaviour), less concern about being infected with SARS-CoV-2, and concerns about the safety and effectiveness of vaccines for both cohorts. Maintaining inter-pandemic trust in vaccines, ensuring rapid data generation during pandemics regarding vaccine safety and effectiveness, and effective and transparent communication about these data are all needed to support pandemic vaccination programs.

Engaging Trusted Messengers to Increase COVID-19 Pediatric Vaccine Uptake in Philadelphia: Lessons from the VaxUpPhillyFamilies program

INTRODUCTION

Communities of color had higher rates of Coronavirus (COVID-19) infection and lower rates of COVID-19 vaccination during the pandemic. Parental concern about the safety and necessity of pediatric COVID-19 vaccines contribute to low childhood vaccination. Enlisting parents and caregivers as trusted messengers is an evidence-based approach to mitigate this challenge. VaxUpPhillyFamilies was formed to engage parents and caregivers as vaccine ambassadors to increase vaccination rates in children of color. This study aimed to understand the key benefits, challenges, and lessons learned from the VaxUpPhillyFamilies program.

METHODS

Three online debriefing sessions with ambassadors were conducted between September 7 and October 24, 2022, to share best practices, address challenges, receive emerging vaccine information, and provide support. Thematic analysis was utilized to develop broad themes and subthemes.

RESULTS

Four themes with corresponding subthemes were identified: 1) Motivations to Become an Ambassador: a) improving the health of the community and b) personal satisfaction; 2) Defining Success: a) community interactions and b) influencing opinions; 3) Best Approaches: a) being mentally prepared with facts, b) addressing community health needs beyond COVID-19, c) demonstrating empathy, d) "meeting them where they're at" by motivational interviewing, and e) building trust and connection; 4) Challenges: a) changes in vaccine guidelines, b) vaccine misinformation, c) varied perceptions of severity of COVID-19 illness and benefits of the vaccine, d) breakdown of communication from trusted sources, and e) structural barriers to engagement.

CONCLUSION

Parents and caregivers were a resource for delivering evidence-based messaging about COVID-19 and other health challenges. To effectively equip parents and caregivers as public health ambassadors, it is critical to offer training in engagement strategies, to identify and combat misinformation, and to provide support in navigating challenges. VaxUpPhillyFamilies program is a model for future public health campaigns.

COVID-19 vaccine uptake in a predominantly minoritized cohort hospitalized during the early pandemic in New York City

BACKGROUND

Minoritized communities in the United States have had higher COVID-19 mortality and lower vaccine uptake. The influence of previous SARS-CoV-2 infection, initial disease severity, and persistent symptoms on COVID-19 vaccine uptake in Black and Latinx communities has not been examined.

OBJECTIVE

To investigate whether initial COVID-19 severity, persistent symptoms, and other correlates affected vaccine uptake in a predominantly minoritized cohort hospitalized for COVID-19 during the early pandemic in New York City.

DESIGN

In this historical cohort study, we abstracted electronic health record data on demographics, comorbidities, hospital oxygen requirements, symptoms at 3 and 6 months post-admission, COVID-19 vaccinations through November 2022, and influenza vaccinations during the 2018-2019 through 2021-2022 seasons. Unadjusted and adjusted odds ratios were estimated through logistic regression analyses of correlates of COVID-19 vaccination, on-time vaccination, and boosting.

PARTICIPANTS

Survivors among the first 1186 adult patients hospitalized for COVID-19 between March 1 and April 8, 2020 at a large quaternary care medical center in Northern Manhattan.

MAIN MEASURES

Uptake of at least one COVID-19 vaccine dose, uptake of at least one booster, and on-time vaccination.

KEY RESULTS

The 890 surviving individuals were predominantly Latinx (54%) and Non-Hispanic Black (15%). Most had one or more comorbidities (67%), and received at least one COVID-19 vaccine dose (78%). Among those vaccinated, 57% received at least one booster, and 31% delayed vaccination. 67% experienced persistent symptoms. Multiple logistic regression showed no association between vaccine uptake and disease severity or symptom persistence. However, older age and influenza vaccination during the COVID-19 era were associated with increased vaccination, booster uptake, and on-time vaccination.

CONCLUSIONS

Pinpointing drivers of vaccine uptake and hesitancy is critical to increasing and sustaining COVID-19 vaccination as the field transitions to annual boosters. The association between influenza vaccination and increased vaccine uptake suggests that bundling vaccines for adults may be an effective delivery strategy.

Impact of waning immunity against SARS-CoV-2 severity exacerbated by vaccine hesitancy

The SARS-CoV-2 pandemic has generated a considerable number of infections and associated morbidity and mortality across the world. Recovery from these infections, combined with the onset of large-scale vaccination, have led to rapidly-changing population-level immunological landscapes. In turn, these complexities have highlighted a number of important unknowns related to the breadth and strength of immunity following recovery or vaccination. Using simple mathematical models, we investigate the medium-term impacts of waning immunity against severe disease on immuno-epidemiological dynamics. We find that uncertainties in the duration of severity-blocking immunity (imparted by either infection or vaccination) can lead to a large range of medium-term population-level outcomes (i.e. infection characteristics and immune landscapes). Furthermore, we show that epidemiological dynamics are sensitive to the strength and duration of underlying host immune responses; this implies that determining infection levels from hospitalizations requires accurate estimates of these immune parameters. More durable vaccines both reduce these uncertainties and alleviate the burden of SARS-CoV-2 in pessimistic outcomes. However, heterogeneity in vaccine uptake drastically changes immune landscapes toward larger fractions of individuals with waned severity-blocking immunity. In particular, if hesitancy is substantial, more robust vaccines have almost no effects on population-level immuno-epidemiology, even if vaccination rates are compensatorily high among vaccine-adopters. This pessimistic scenario for vaccination heterogeneity arises because those few individuals that are vaccine-adopters are so readily re-vaccinated that the duration of vaccinal immunity has no appreciable consequences on their immune status. Furthermore, we find that this effect is heightened if vaccine-hesitants have increased transmissibility (e.g. due to riskier behavior). Overall, our results illustrate the necessity to characterize both transmission-blocking and severity-blocking immune time scales. Our findings also underline the importance of developing robust next-generation vaccines with equitable mass vaccine deployment.

Public Willingness to Mask and Vaccinate in the Future: Results From a 2023 Nationally Representative Survey of US Adults

The enduring spread of COVID-19 and other respiratory viruses highlights a need for greater focus on long-term public willingness to perform protective behaviors. Although COVID-19 is no longer considered a public health emergency of international concern, it is unknown whether people in the United States plan to continue protective behaviors to protect themselves and others against infection. To inform planning and communications, we used a nationally representative survey of 1,936 US adults to examine attitudes and intentions toward future vaccination and mask-wearing. A majority believed COVID-19 vaccines were safe (73%) and effective in protecting against serious illness (72%). One-third (33%) had strong intentions to get an updated COVID-19 vaccine most years in the future. Among those with weaker intentions (n=1,287), many cited concerns about safety (71%) and efficacy (64%), lack of trust in institutions (64%), or beliefs that prior vaccination or infection protected them (62%). Approximately two-thirds (69%) of respondents believed masks were effective in protecting the wearer from getting COVID-19, and a majority appeared moderately receptive to future public mask-wearing, particularly when there was proximate risk of infection from COVID-19 (67%) or other respiratory viruses (59%). Men, non-Hispanic White adults, younger adults, rural residents, and adults with higher incomes, without college degrees, and without serious medical conditions or physical limitations were more likely to indicate resistance toward future COVID-19 vaccination and/or mask-wearing. Findings support tailored messaging to address concerns and opportunities among different populations, as well as support for communications programs and community engagement to motivate future uptake.

A health equity science approach to assessing drivers of COVID-19 vaccination coverage disparities over the course of the COVID-19 pandemic, United States, December 2020-December 2022

INTRODUCTION

Health equity science examines underlying social determinants, or drivers, of health inequities by building an evidence base to guide action across programs, public health surveillance, policy, and communications efforts. A Social Vulnerability Index (SVI) was utilized during the COVID-19 response to identify areas where inequities exist and support communities with vaccination. We set out to assess COVID-19 vaccination coverage by two SVI themes, Racial and Ethnicity Minority Status and Housing Type and Transportation to examine disparities.

METHODS

US county-level COVID-19 vaccine administration data among persons aged 5 years and older reported to the Centers for Disease Control and Prevention from December 14, 2020 to December 14, 2022, were analyzed. Counties were categorized 1) into tertiles (low, moderate, high) according to each SVI theme's level of vulnerability or 2) dichotomized by urban or rural classification. Primary series vaccination coverage per age group were assessed for SVI social factors by SVI theme tertiles or urbanicity.

RESULTS

Older adults aged 65 years and older had the highest vaccination coverage across all vulnerability factors compared with children aged 5-17 years and adults aged 18-64 years. Overall, children and adults had higher vaccination coverage in counties of high vulnerability. Greater vaccination coverage differences were observed by urbanicity as rural counties had some of the lowest vaccination coverage for children and adults.

CONCLUSION

COVID-19 vaccination efforts narrowed gaps in coverage for adults aged 65 years and older but larger vaccination coverage differences remained among younger populations. Moreover, greater disparities in coverage existed in rural counties. Health equity science approaches to analyses should extend beyond identifying differences by basic demographics such as race and ethnicity and include factors that provide context (housing, transportation, age, and geography) to assist with prioritization of vaccination efforts where true disparities in vaccination coverage exist.

Evolution of the Antigenic Landscape in Children and Young Adults with COVID-19 and MIS-C

There is minimal knowledge regarding the durability of neutralization capacity and level of binding antibody generated against the highly transmissible circulating Omicron subvariants following SARS-CoV-2 infection in children with acute COVID-19 and those diagnosed with multisystem inflammatory syndrome in children (MIS-C) in the absence of vaccination. In this study, SARS-CoV-2 neutralization titers against the ancestral strain (WA1) and Omicron sublineages were evaluated in unvaccinated children admitted for COVID-19 (n = 32) and MIS-C (n = 32) at the time of hospitalization (baseline) and at six to eight weeks post-discharge (follow-up) between 1 April 2020, and 1 September 2022. In addition, antibody binding to the spike receptor binding domain (RBD) from WA1, BA.1, BA.2.75, and BA.4/BA.5 was determined using surface plasmon resonance (SPR). At baseline, the children with MIS-C demonstrated two-fold to three-fold higher binding and neutralizing antibodies against ancestral WA1 compared to those with COVID-19. Importantly, in children with COVID-19, the virus neutralization titers against the Omicron subvariants at six to eight weeks post-discharge reached the same level as those with MIS-C had at baseline but were higher than titers at 6-8 weeks post-discharge for MIS-C cases. Cross-neutralization capacity against recently emerged Omicron BQ.1, BQ.1.1, and XBB.1 variants was very low in children with either COVID-19 or MIS-C at all time points. These findings about post-infection immunity in children with either COVID-19 or MIS-C suggest the need for vaccinations in children with prior COVID-19 or MIS-C to provide effective protection from emerging and circulating SARS-CoV-2 variants.

Life expectancy among Native Americans during the COVID-19 pandemic: estimates, uncertainty, and obstacles

Few reliable estimates have been available for assessing the impact of the COVID-19 pandemic on mortality among Native Americans. Using deidentified publicly available data on deaths and populations by age, we estimated life expectancy for the years 2019-2022 for single-race non-Hispanic Native Americans. Life expectancy in 2022 was 67.8 years, 2.3 years higher than in 2021 but a huge 4-year loss from 2019. Although our life expectancy estimates for 2022 varied under different assumptions about racial/ethnic classification and age misreporting errors, all estimates were lower than the average for middle-income countries. Estimates of losses and gains in life expectancy were consistent across assumptions. Large reductions in COVID-19 death rates between 2021 and 2022 were largely offset by increases in rates of death from unintentional injuries (particularly drug overdoses), chronic liver disease, diabetes, and heart disease, underscoring the difficulties facing Native Americans in achieving reductions in mortality, let alone returning to levels of mortality prior to the pandemic. Serious data problems have persisted for many years, but the scarcity and inadequacy of estimates during the pandemic have underscored the urgent need for timely and accurate demographic data on the Native American population.

New variants of COVID-19 (XBB.1.5 and XBB.1.16, the "Arcturus"): A review of highly questioned concerns, a brief comparison between different peaks in the COVID-19 pandemic, with a focused systematic review on expert recommendations for prevention, vaccination, and treatment measures in the general population and at-risk groups

INTRODUCTION

The COVID-19 pandemic has taken many forms and continues to evolve, now around the Omicron wave, raising concerns over the globe. With COVID-19 being declared no longer a "public health emergency of international concern (PHEIC)," the COVID pandemic is still far from over, as new Omicron subvariants of interest and concern have risen since January of 2023. Mainly with the XBB.1.5 and XBB.1.16 subvariants, the pandemic is still very much "alive" and "breathing."

METHODS

This review consists of five highly concerning questions about the current state of the COVID Omicron peak. We searched four main online databases to answer the first four questions. For the last one, we performed a systematic review of the literature, with keywords "Omicron," "Guidelines," and "Recommendations."

RESULTS

A total of 31 articles were included. The main symptoms of the current Omicron wave include a characteristically high fever, coughing, conjunctivitis (with itching eyes), sore throat, runny nose, congestion, fatigue, body ache, and headache. The median incubation period of the symptoms is shorter than the previous peaks. Vaccination against COVID can still be considered effective for the new subvariants.

CONCLUSION

Guidelines recommend continuation of personal protective measures, third and fourth dose boosters, along with administration of bivalent messenger RNA vaccine boosters. The consensus antiviral treatment is combination therapy using Nirmatrelvir and Ritonavir, and the consensus for pre-exposure prophylaxis is Tixagevimab and Cilgavimab combination. We hope the present paper raises awareness for the continuing presence of COVID and ways to lower the risks, especially for at-risk groups.

Comparative safety profile of bivalent and original COVID-19 mRNA vaccines regarding myocarditis/pericarditis: A pharmacovigilance study

OBJECTIVES

Bivalent COVID-19 mRNA vaccines, which contain two different components, were authorized to provide protection against both the original strain of SARS-CoV-2 and the Omicron variant as a measure to address the COVID-19 pandemic. Concerns regarding the risk of myocarditis/pericarditis associated with bivalent vaccination have been raised due to the observed superior neutralizing antibody responses. This study aimed to investigate the risk of myocarditis/pericarditis following bivalent COVID-19 mRNA vaccination compared to monovalent vaccination.

METHODS

The CDC COVID Data Tracker and the Vaccines Adverse Event Reporting System (VAERS) were analyzed between December 13, 2020 to March 8, 2023. Reporting rates were determined by dividing the number of myocarditis/pericarditis cases by the total number of vaccine doses administered. Disproportionality patterns regarding myocarditis/pericarditis were evaluated for various COVID-19 mRNA vaccinations using reporting odds ratios (RORs).

RESULTS

The reporting rate for myocarditis/pericarditis following original monovalent COVID-19 mRNA vaccination was 6.91 (95 % confidence interval [95 %CI] 6.71-7.12) per million doses, while the reporting rate for bivalent vaccination was significantly lower (1.24, 95%CI 0.96-1.58). Disproportionality analysis revealed a higher reporting of myocarditis/pericarditis following original vaccination with a ROR of 2.21 (95 %CI 2.00-2.43), while bivalent COVID-19 mRNA vaccination was associated with fewer reports of myocarditis/pericarditis (ROR 0.57, 95 %CI 0.45-0.72). Sub-analyses based on symptoms, sex, age and manufacturer further supported these findings.

CONCLUSION

This population-based study provides evidence that bivalent COVID-19 mRNA vaccination is not associated with risk of myocarditis/pericarditis. These findings provide important insights into the safety profile of bivalent COVID-19 mRNA vaccines and support their continued use as updated boosters.

Who is getting COVID-19 boosters? A latent class analysis in a nationally representative sample of Mexican adults 60 years and over

OBJECTIVE

Estimate COVID-19 vaccine booster uptake and identify sociodemographic profiles associated with vaccine booster uptake in Mexican adults aged 60 and older.

METHODS

Using data from the 2022 National Health and Nutrition Survey, we estimated COVID-19 booster uptake in Mexican adults 60 and older. We conducted a latent class analysis using sociodemographic characteristics and then estimated group-specific booster prevalence.

RESULTS

Adults aged 60 and older with a completed vaccination schedule had 80.3% booster coverage. Two groups showed the lowest coverage: 1) unemployed and informal working men with elementary education with low socioeconomic status (73.8% boosted), and 2) female homekeepers with elementary education or less living in rural areas (77.0% boosted).

CONCLUSIONS

Our analysis points to the need to reach out to men and women with elementary education or less who live in rural areas to strengthen booster campaigns in the future.

Association between COVID-19 Booster Vaccination and COVID-19 Outcomes among U.S. Adults

Understanding the association between booster vaccination and COVID-19 outcomes can help strengthen post-pandemic messaging and strategies to increase vaccination and reduce severe and long-term consequences of COVID-19. Using the Household Pulse Survey data collected from U.S. adults from 9 December 2022 to 13 February 2023 (n = 214,768), this study assessed the relationship between COVID-19 booster vaccination and COVID-19 outcomes (testing positive for COVID-19, moderate/severe COVID-19, and long COVID). Disparities were found in COVID-19 outcomes (e.g., testing positive for COVID-19, moderate/severe COVID-19, and long COVID) by sociodemographic characteristics, region of residence, food insecurity status, mental health status, disability status, and housing type. Receipt of a COVID-19 booster vaccination was negatively associated with testing positive for COVID-19 (aOR = 0.75, 95%CI: 0.72,0.79), having moderate/severe COVID-19 (aOR = 0.92, 95%CI: 0.88, 0.97), or having long COVID (aOR = 0.86 (0.80, 0.91)). Even among those who tested positive for COVID-19, those who received the booster vaccine were less likely to have moderate/severe COVID-19 and less likely to have long COVID. Communicating the benefits of COVID-19 booster vaccination, integrating vaccination in patient visits, and reducing access barriers can increase vaccination uptake and confidence for all individuals and protect them against the severe negative outcomes of COVID-19.

Social and demographic factors associated with receipt of a COVID-19 vaccine initial booster dose and with interval between primary series completion and initial booster dose uptake among persons aged ≥ 12 years, United States, August 2021-October 2022

COVID-19 booster dose vaccination has been crucial in ensuring protection against COVID-19 including recently predominant Omicron variants. Because vaccines against newer SARS-CoV- 2 variants are likely to be recommended in future, it will be valuable to understand past booster dose uptake among different demographic groups. Using U.S. vaccination data, this study examined intervals between primary series completion and receipt of first booster dose (monovalent or bivalent) during August 2021 - October 2022 among persons ≥12 years of age who had completed a COVID-19 vaccine primary series by October 2021. Sub-populations who were late booster recipients (received a booster dose ≥12 months after the primary series) or received no booster dose included persons <35 years old, Johnson & Johnson/Janssen vaccine primary dose recipients, persons in certain racial and ethnic groups, and persons living in rural and more socially vulnerable areas, and in the South region of the United States; these groups may benefit the most from public health outreach efforts to achieve timely COVID-19 vaccination completion in future.

Comparing frequency of booster vaccination to prevent severe COVID-19 by risk group in the United States

There is a public health need to understand how different frequencies of COVID-19 booster vaccines may mitigate the risk of severe COVID-19, while accounting for waning of protection and differential risk by age and immune status. By analyzing United States COVID-19 surveillance and seroprevalence data in a microsimulation model, here we show that more frequent COVID-19 booster vaccination (every 6-12 months) in older age groups and the immunocompromised population would effectively reduce the burden of severe COVID-19, while frequent boosters in the younger population may only provide modest benefit against severe disease. In persons 75+ years, the model estimated that annual boosters would reduce absolute annual risk of severe COVID-19 by 199 (uncertainty interval: 183-232) cases per 100,000 persons, compared to a one-time booster vaccination. In contrast, for persons 18-49 years, the model estimated that annual boosters would reduce this risk by 14 (10-19) cases per 100,000 persons. Those with prior infection had lower benefit of more frequent boosting, and immunocompromised persons had larger benefit. Scenarios with emerging variants with immune evasion increased the benefit of more frequent variant-targeted boosters. This study underscores the benefit of considering key risk factors to inform frequency of COVID-19 booster vaccines in public health guidance and ensuring at least annual boosters in high-risk populations.

"Every Time It Comes Time for Another Shot, It's a Re-Evaluation": A Qualitative Study of Intent to Receive COVID-19 Boosters among Parents Who Were Hesitant Adopters of the COVID-19 Vaccine

COVID-19 vaccine coverage remains low for US children, especially among those living in rural areas and the Southern/Southeastern US. As of 12 September 2023, the CDC recommended bivalent booster doses for everyone 6 months and older. Emerging research has shown an individual may be vaccine hesitant and also choose to receive a vaccine for themselves or their child(ren); however, little is known regarding how hesitant adopters evaluate COVID-19 booster vaccinations. We used an exploratory qualitative descriptive study design and conducted individual interviews with COVID-19 vaccine-hesitant adopter parents (n = 20) to explore COVID-19 parental intentions to have children receive COVID-19 boosters. Three primary themes emerged during the analysis: risk, confidence, and intent, with risk assessments from COVID-19 and COVID-19 vaccine confidence often related to an individual parent's intent to vaccinate. We also found links among individuals with persistent concerns about the COVID-19 vaccine and low COVID-19 vaccine confidence with conditional and/or low/no intent and refusal to receive recommended boosters for children. Our findings suggest that healthcare providers and public health officials should continue making strong recommendations for vaccines, continue to address parental concerns, and provide strong evidence for vaccine safety and efficacy even among the vaccinated.

The role of funded partnerships in working towards decreasing COVID-19 vaccination disparities, United States, March 2021-December 2022

During the COVID-19 vaccination rollout from March 2021- December 2022, the Centers for Disease Control and Prevention funded 110 primary and 1051 subrecipient partners at the national, state, local, and community-based level to improve COVID-19 vaccination access, confidence, demand, delivery, and equity in the United States. The partners implemented evidence-based strategies among racial and ethnic minority populations, rural populations, older adults, people with disabilities, people with chronic illness, people experiencing homelessness, and other groups disproportionately impacted by COVID-19. CDC also expanded existing partnerships with healthcare professional societies and other core public health partners, as well as developed innovative partnerships with organizations new to vaccination, including museums and libraries. Partners brought COVID-19 vaccine education into farm fields, local fairs, churches, community centers, barber and beauty shops, and, when possible, partnered with local healthcare providers to administer COVID-19 vaccines. Inclusive, hyper-localized outreach through partnerships with community-based organizations, faith-based organizations, vaccination providers, and local health departments was critical to increasing COVID-19 vaccine access and building a broad network of trusted messengers that promoted vaccine confidence. Data from monthly and quarterly REDCap reports and monthly partner calls showed that through these partnerships, more than 295,000 community-level spokespersons were trained as trusted messengers and more than 2.1 million COVID-19 vaccinations were administered at new or existing vaccination sites. More than 535,035 healthcare personnel were reached through outreach strategies. Quality improvement interventions were implemented in healthcare systems, long-term care settings, and community health centers resulting in changes to the clinical workflow to incorporate COVID-19 vaccine assessments, recommendations, and administration or referrals into routine office visits. Funded partners' activities improved COVID-19 vaccine access and addressed community concerns among racial and ethnic minority groups, as well as among people with barriers to vaccination due to chronic illness or disability, older age, lower income, or other factors.

COVID-19 Vaccine Confidence Mediates the Relationship between Health Literacy and Vaccination in a Diverse Sample of Urban Adults

We sought to analyze the relationship between health literacy, confidence in COVID-19 vaccines, and self-reported vaccination. We hypothesized that the relationship between health literacy and vaccination would be mediated by vaccine confidence. We recruited (N = 271) English- and Spanish-speaking adults in Boston and Chicago from September 2018 to September 2021. We performed a probit mediation analysis to determine if confidence in COVID-19 vaccines and health literacy predicted self-reported vaccination. We hypothesized that the relationship between health literacy and vaccination would be mediated by vaccine confidence. Participants were on average 50 years old, 65% female, 40% non-Hispanic Black, 25% Hispanic, and 30% non-Hispanic White; 231 (85%) reported at least one COVID-19 vaccination. A higher mean vaccine confidence score (t = -7.9, p < 0.001) and higher health literacy (t = -2.2, p = 0.03) were associated with vaccination, but only vaccine confidence predicted vaccination in a multivariate model. Vaccine confidence mediated the relationship between health literacy and COVID-19 vaccination (mediated effects: 0.04; 95% CI [0.02, 0.08]). We found that using a simple tool to measure vaccine confidence identified people who declined or delayed COVID-19 vaccination in a diverse sample of adults with varying levels of health literacy. Simple short survey tools can be useful to identify people who may benefit from vaccine promotion efforts and evidence-based communication strategies.

Evolution of neutralizing antibodies through vaccination and breakthrough infections in the era of COVID-19 endemicity

Despite a high vaccination rate, the COVID-19 pandemic continues with immune-evading Omicron variants. The success of additional antigenic stimulation through breakthrough infection (BI) and updated vaccination in overcoming antigenic imprinting needs to be determined. Participants in a long-term follow-up cohort of healthcare worker (HCW) vaccinee were categorized according to their infection/vaccination status. Anti-SARS-CoV-2 spike/nucleocapsid protein antibodies were measured, and plaque reduction neutralization tests (PRNTs) against wild-type (WT), BA.5, BN.1, and XBB.1.5 were conducted. The neutralization activity of intravenous immunoglobulin (IVIG) products was evaluated to assess the immune status of the general population. Ninety-five HCWs were evaluated and categorized into seven groups. The WT PRNT ND50 value was highest regardless of infection/vaccination status, and groups with recent antigenic stimulation showed high PRNT titers overall. Groups with double Omicron stimulation, either by BI plus BA.4/5 bivalent vaccination or repeated BI, exhibited significantly higher BA.5 and BN.1 PRNT to WT PRNT ratios than those with single Omicron stimulation. Overall group immunity was estimated to be boosted in January 2023, reflecting the effect of the BA.4/5 bivalent booster and additional BIs, but slightly declined in June 2023. A substantial increase in the antibody concentrations of IVIG products was noticed in 2022, and recently produced IVIG products exhibited a substantial level of cross-reactive neutralizing activity against emerging variants. Neutralizing activity against emerging variants could be enhanced by repeated antigenic stimulation via BI and/or updated vaccination. Overall group immunity was elevated accordingly, and IVIG products showed substantial activity against circulating strains.

Vaccine effectiveness of COVID-19 and rebound in the real world

We intend to evaluate the relationship between the rates of global SARS-CoV-2 vaccination and the number of COVID-19 confirmed cases, as well as the mortality rate after the declaration of a pandemic. Of the data from 191 countries at the time of data retraction, we selected 111 countries that have SARS-CoV-2 vaccination reports. We stratified countries into high-income and non-high-income countries (HIC and non-HIC) based on World Bank income-group. We used a fixed-effects model (FEM) and performed a longitudinal analysis. The number of confirmed cases decreased as the vaccination rates increased in both non-HICs (B =  - 0.027, T =  - 2.0) and HICs (B =  - 0.207, T =  - 17.5). The number of deaths decreased as the vaccination rates increased in both non-HICs (B =  - 0.151, T =  - 2.3) and HICs (B =  - 0.230, T =  - 40.9). For full vaccination, this measure had a negative association with daily confirmed cases and daily deaths in both non-HICs and HICs. In non-HICs, daily cases and daily deaths decreased as the first vaccination and full vaccination coverages increased. However in HICs, daily cases and daily deaths decreased as the first vaccination and full vaccination coverages increased in the early phase, but after a certain period, they tended to increase again. We observed a significant association between the increase in vaccination coverage in the real world and reduced daily confirmed cases and deaths. However, as the confirmed cases and deaths have rebounded in HICs, our findings indicate that COVID-19 is not completely prevented through vaccine distribution.

Increasing equity in adult immunization through community-level action

Inequities in availability and access to adult vaccinations represent significant gaps in the US public health infrastructure. Adults in racial and ethnic minority groups are less likely to receive routinely recommended vaccinations due to systemic barriers, distribution inequities, and lack of trust in vaccines; similar disparities were seen during early COVID-19 vaccination efforts. However, a deliberate focus on reducing disparities can yield progress. National data show narrowing of racial and ethnic adult COVID-19 vaccination coverage disparities over time, highlighting the value of the equity-focused, community-level interventions implemented during the pandemic. This paper describes the Centers for Disease Control and Prevention's efforts during the COVID-19 pandemic to address racial and ethnic disparities in adult immunization, and how lessons learned may be applied post-pandemic. Progress made is likely to be lost without sustained support for adult vaccination at national, state, and community levels.

Disparities in child and adolescent COVID-19 vaccination coverage and parental intent toward vaccinations for their children and adolescents

INTRODUCTION

Despite recommendations for COVID-19 primary series completion and booster doses for children and adolescents, coverage has been less than optimal, particularly in some subpopulations. This study explored disparities in childhood/adolescent COVID-19 vaccination, parental intent to vaccinate their children and adolescents, and reasons for non-vaccination in the US.

METHODS

Using the U.S. Census Bureau's Household Pulse Survey (HPS), we analyzed households with children aged <18 years using data collected from September 14 to November 14, 2022 (n = 44,929). Child and adolescent COVID-19 vaccination coverage (≥1 dose, completed primary series, and booster vaccination) and parental intentions toward vaccination were assessed by sociodemographic characteristics. Factors associated with child and adolescent vaccination coverage were examined using multivariable regression models. Reasons for non-vaccination were assessed overall, by the child's age group and respondent's age group.

RESULTS

Overall, approximately half (50.1%) of children aged < 18 years were vaccinated against COVID-19 (≥1 dose). Completed primary series vaccination was 44.2% among all children aged <18 years. By age group, completed primary series was 13.2% among children <5 years, 43.9% among children 5-11 years, and 63.3% among adolescents 12-17 years. Booster vaccination among those who completed the primary series was 39.1% among children 5-11 years and 55.3% among adolescents 12-17 years. Vaccination coverage differed by race/ethnicity, educational attainment, household income, region, parental COVID-19 vaccination status, prior COVID-19 diagnosis, child's age group, and parental age group. Parental reluctance was highest for children aged <5 years (46.8%). Main reasons for non-vaccination among reluctant parents were concerns about side effects (53.3%), lack of trust in COVID-19 vaccines (48.7%), and the belief that children do not need a COVID-19 vaccine (38.8%).

CONCLUSION

Disparities in COVID-19 vaccination coverage among children and adolescents continue to exist. Further efforts are needed to increase COVID-19 primary series and booster vaccination and parental confidence in vaccines.

Factors associated with uptake of bivalent mRNA COVID-19 vaccines in a large US health care system

BACKGROUND

Bivalent mRNA COVID-19 vaccines were developed to provide protection against the original SARS-CoV-2 strain and Omicron BA.4/BA.5 variants, but uptake in the United States has been low. Sociodemographic disparities in COVID-19 vaccine uptake have been documented, but it is unclear if similar disparities persist among individuals who previously completed a primary series of monovalent COVID-19 vaccine.

METHODS

We conducted a retrospective cohort study at Kaiser Permanente Southern California (KPSC) including youth aged 5-17 years and adults aged ≥18 years who were KPSC members and had completed a primary series of monovalent COVID-19 vaccine. Individuals were followed from index date (date of eligibility for bivalent vaccine) to 03/31/2023 to ascertain receipt of any dose of bivalent mRNA COVID-19 vaccine or until disenrollment from KPSC or death. Multivariable robust Poisson regression was conducted to assess the adjusted relative risk and 95 % confidence intervals of factors associated with receipt of bivalent vaccine.

RESULTS

The final cohorts included 305,339 youth and 2,534,619 adults, of whom 19.5 % and 30.7 %, respectively, had received bivalent COVID-19 vaccine. Factors associated with being more likely to receive bivalent COVID-19 vaccine included older age, Asian race, more prior year outpatient and virtual visits, Charlson score ≥1, and immunocompromised status. Factors associated with being less likely to receive a bivalent COVID-19 vaccine included age 12-17 vs 5-11 years, Hispanic and non-Hispanic Black race/ethnicity, ≥1 prior year inpatient or emergency department visits, prior history of SARS-CoV-2 infection (adults only), Medicaid insurance, and higher neighborhood deprivation index.

CONCLUSION

Even among youth and adults who had previously received a primary series of monovalent COVID-19 vaccine, sociodemographic and clinical disparities were observed in receipt of bivalent COVID-19 vaccine. These findings are critical to inform equitable strategies for the implementation of the updated monovalent COVID-19 vaccine targeting the Omicron XBB strain.

COVID-19 Vaccination Messengers, Communication Channels, and Messages Trusted Among Black Communities in the USA: a Review

Black and African American adults exhibited higher levels of mistrust and vaccine hesitancy and lower levels of vaccination throughout the COVID-19 pandemic. Vaccination and booster uptake remains disproportionately low among Black adults. We conducted a systematic review of empirical research published between February 2021 and July 2022 from five electronic databases and the grey literature. We screened studies that assessed COVID-19 vaccination information needs and preferences as well as communication strategies among Black adults in the USA. We extracted data, then analyzed and synthesized results narratively. Twenty-two articles were included: 2 interventions, 3 experimental surveys, 7 observational surveys, 8 qualitative inquiries, and 2 mixed methods studies. Studies reported credible and preferred COVID-19 vaccination information sources/messengers, channels, and content. Commonly trusted messengers included personal health care providers, social network connections, and church/faith leaders. Electronic outreach (e.g., email, text messages), community events (e.g., forums, canvassing), and social media were popular. Black communities wanted hopeful, fact-based messages that address racism and mistrust; persuasive messages using collective appeals about protecting others may be more influential in changing behavior. Future communication strategies aiming to increase vaccine confidence and encourage COVID-19 booster vaccination among Black communities should be developed in partnership with community leaders and local health care providers to disseminate trauma-informed messages with transparent facts and collective action appeals across multiple in-person and electronic channels.

The Effectiveness of Bivalent COVID-19 Vaccination: A Preliminary Report

Vaccination has been a game-changer in the long battle against COVID-19. However, waning vaccine-induced immunity and the immune evasion of emerging variants create challenges. The rapid-fire development of bivalent vaccines (BVs), comprising ancestral strains and a new variant, was authorized to prevent COVID-19, but the effectiveness of the updated vaccines remains largely unclear. Electronic databases were searched to investigate the immunogenicity and reactogenicity of BVs in humans. As of March 2023, 20 trials were identified. Compared with monovalent vaccination, the induced immunogenicity against ancestral strains was similar. The BVs demonstrated approximately 33-50% higher immunogenicity values against additional variant strains. An observational cohort study showed the additional clinical effectiveness of the BVs. The adverse events were similar. In conclusion, our systematic review found that the BVs had equal immunogenicity against ancestral strains without safety concerns. Approximately 33-50% increased additional antibody titers and clinical effectiveness against additional variant strains were observed in subjects with a BV vaccine with moderate heterogeneity, especially for BA.1-containing BVs.

Profile and Outcomes of Hospitalized COVID-19 Patients during the Prevalence of the Omicron Variant According to the Brazilian Regions: A Retrospective Cohort Study from 2022

We investigated the clinical-epidemiological profile and outcomes of COVID-19 patients hospitalized in 2022, during the Omicron variant/subvariant prevalence, in different Brazilian regions to identify the most vulnerable subgroups requiring special attention. Data from COVID-19 patients were extracted from the national Information System for Epidemiological Surveillance of Influenza (SIVEP-Gripe database), and analyses stratified by region and age group were conducted. The constructed dataset encompassed clinical-epidemiological information, intensive care unit admission, invasive and non-invasive ventilation requirements, vaccination status, and evolution (cure or death). It was observed that there were significant differences in the vaccination rates between regions, in the occurrence of unfavorable outcomes, and in the pattern of comorbidities in young patients. The north region had higher rates of unvaccinated patients and a lower percentage of those vaccinated with three doses in all age groups compared to other regions. The northeast region had the highest rates of patients admitted to the ICU for all age groups, while the north and northeast were the most affected by IMV requirements and in-hospital death in all age groups. This study showed that extended vaccination coverage, especially booster doses, can protect different population segments from developing severe disease since lower vaccination coverage was observed in regions with higher fatality rates.

Attitudes and Values of US Adults Not Yet Up-to-Date on COVID-19 Vaccines in September 2022

(1) Background: Periodic resurgences in COVID-19 due to more contagious variants highlight the need to increase coverage of booster doses. (2) Methods: Our September 2022 nationally representative survey of US adults measured COVID-19 vaccination status, intentions, attitudes, values, and confidence in information sources. (3) Findings: Although 85% of the weighted sample reported receiving at least one dose of a COVID-19 vaccine, only 63% reported being up-to-date on COVID-19 vaccines (e.g., received a booster dose). Only 12% of those not yet up-to-date indicated they were likely to get up-to-date as soon as possible, whereas 42% were unlikely to ever get up-to-date, and 46% were still uncertain. Most of those not up-to-date on their COVID-19 vaccines were under 45 years of age (58%), without a bachelor's degree (76%), making under $75,000 annually (53%), and Republican or Independent (82%). Prevalent concerns about COVID-19 vaccines among those uncertain about getting up-to-date included: potential side effects that have not been figured out yet (88%), speed of development (77%), newness (75%), ingredients (69%), drug companies making money (67%), allergic reactions (65%), and experimenting on people (63%). (4) Conclusions: Nearly half of adults not yet up-to-date on COVID-19 vaccines were uncertain about doing so, indicating an opportunity to support their decision-making.