Cross-Reactivity of Two SARS-CoV-2 Serological Assays in a Setting Where Malaria Is Endemic.

Accurate SARS-CoV-2 serological assays are critical for COVID-19 serosurveillance. However, previous studies have indicated possible cross-reactivity of these assays, including in areas where malaria is endemic. We tested 213 well-characterized prepandemic samples from Nigeria using two SARS-CoV-2 serological assays, Abbott Architect IgG and Euroimmun NCP IgG assay, both targeting SARS-CoV-2 nucleocapsid protein. To assess antibody binding strength, an avidity assay was performed on these samples and on plasma from SARS-CoV-2 PCR-positive persons. Thirteen (6.1%) of 212 samples run on the Abbott assay and 38 (17.8%) of 213 run on the Euroimmun assay were positive. Anti-Plasmodium IgG levels were significantly higher among false positives for both Abbott and Euroimmun; no association was found with active Plasmodium falciparum infection. An avidity assay using various concentrations of urea wash in the Euroimmun assay reduced loosely bound IgG: of 37 positive/borderline prepandemic samples, 46%, 86%, 89%, and 97% became negative using 2 M, 4 M, 5 M, and 8 M urea washes, respectively. The wash slightly reduced avidity of antibodies from SARS-CoV-2 patients within 28 days of PCR confirmation; thereafter, avidity increased for all urea concentrations except 8 M. This validation found moderate to substantial cross-reactivity on two SARS-CoV-2 serological assays using samples from a setting where malaria is endemic. A simple urea wash appeared to alleviate issues of cross-reactivity.

Implementing a Multisite Clinical Trial in the Midst of an Ebola Outbreak: Lessons Learned From the Sierra Leone Trial to Introduce a Vaccine Against Ebola.

The Sierra Leone Trial to Introduce a Vaccine against Ebola (STRIVE), a phase 2/3 trial of investigational rVSV∆G-ZEBOV-GP vaccine, was conducted during an unprecedented Ebola epidemic. More than 8600 eligible healthcare and frontline response workers were individually randomized to immediate (within 7 days) or deferred (within 18-24 weeks) vaccination and followed for 6 months after vaccination for serious adverse events and Ebola virus infection. Key challenges included limited infrastructure to support trial activities, unreliable electricity, and staff with limited clinical trial experience. Study staff made substantial infrastructure investments, including renovation of enrollment sites, laboratories, and government cold chain facilities, and imported equipment to store and transport vaccine at ≤-60oC. STRIVE built capacity by providing didactic and practical research training to >350 staff, which was reinforced with daily review and feedback meetings. The operational challenges of safety follow-up were addressed by issuing mobile telephones to participants, making home visits, and establishing a nurse triage hotline. Before the Ebola outbreak, Sierra Leone had limited infrastructure and staff to conduct clinical trials. Without interfering with the outbreak response, STRIVE responded to an urgent need and helped build this capacity. CLINICAL TRIALS REGISTRATION: ClinicalTrials.gov [NCT02378753] and Pan African Clinical Trials Registry [PACTR201502001037220].

Influenza Vaccination Coverage Among Health Care Personnel - United States, 2016-17 Influenza Season.

The Advisory Committee on Immunization Practices (ACIP) recommends that all health care personnel (HCP) receive an annual influenza vaccination to reduce influenza-related morbidity and mortality among HCP and their patients and to reduce absenteeism among HCP (1-4). To estimate influenza vaccination coverage among HCP in the United States during the 2016-17 influenza season, CDC conducted an opt-in Internet panel survey of 2,438 HCP. Overall, 78.6% of survey respondents reported receiving vaccination during the 2016-17 season, similar to reported coverage in the previous three influenza seasons (5). Vaccination coverage continued to be higher among HCP working in hospitals (92.3%) and lower among HCP working in ambulatory (76.1%) and long-term care (LTC) (68.0%) settings. As in previous seasons, coverage was highest among HCP who were required by their employer to be vaccinated (96.7%) and lowest among HCP working in settings where vaccination was not required, promoted, or offered on-site (45.8%). Implementing workplace strategies found to improve vaccination coverage among HCP, including vaccination requirements or active promotion of on-site vaccinations at no cost, can help ensure that HCP and patients are protected against influenza (6).

Influenza Vaccination Coverage Among Pregnant Women - United States, 2016-17 Influenza Season.

Pregnant women and their infants are at increased risk for severe influenza-associated illness (1), and since 2004, the Advisory Committee on Immunization Practices (ACIP) has recommended influenza vaccination for all women who are or might be pregnant during the influenza season, regardless of the trimester of the pregnancy (2). To assess influenza vaccination coverage among pregnant women during the 2016-17 influenza season, CDC analyzed data from an Internet panel survey conducted during March 28-April 7, 2017. Among 1,893 survey respondents pregnant at any time during October 2016-January 2017, 53.6% reported having received influenza vaccination before (16.2%) or during (37.4%) pregnancy, similar to coverage during the preceding four influenza seasons. Also similar to the preceding influenza season, 67.3% of women reported receiving a provider offer for influenza vaccination, 11.9% reported receiving a recommendation but no offer, and 20.7% reported receiving no recommendation; among these women, reported influenza vaccination coverage was 70.5%, 43.7%, and 14.8%, respectively. Among women who received a provider offer for vaccination, vaccination coverage differed by race/ethnicity, education, insurance type, and other sociodemographic factors. Use of evidence-based practices such as provider reminders and standing orders could reduce missed opportunities for vaccination and increase vaccination coverage among pregnant women.

Influenza Vaccination Coverage Among Health Care Personnel - United States, 2015-16 Influenza Season.

The Advisory Committee on Immunization Practices recommends annual influenza vaccination for all health care personnel to reduce influenza-related morbidity and mortality among both health care personnel and their patients (1-4). To estimate influenza vaccination coverage among U.S. health care personnel for the 2015-16 influenza season, CDC conducted an opt-in Internet panel survey of 2,258 health care personnel during March 28-April 14, 2016. Overall, 79.0% of survey participants reported receiving an influenza vaccination during the 2015-16 season, similar to the 77.3% coverage reported for the 2014-15 season (5). Coverage in long-term care settings increased by 5.3 percentage points compared with the previous season. Vaccination coverage continued to be higher among health care personnel working in hospitals (91.2%) and lower among health care personnel working in ambulatory (79.8%) and long-term care settings (69.2%). Coverage continued to be highest among physicians (95.6%) and lowest among assistants and aides (64.1%), and highest overall among health care personnel who were required by their employer to be vaccinated (96.5%). Among health care personnel working in settings where vaccination was neither required, promoted, nor offered onsite, vaccination coverage continued to be low (44.9%). An increased percentage of health care personnel reporting a vaccination requirement or onsite vaccination availability compared with earlier influenza seasons might have contributed to the overall increase in vaccination coverage during the past 6 influenza seasons.

Factors Associated With Provider Reporting of Child and Adolescent Vaccination History to Immunization Information Systems: Results From the National Immunization Survey, 2006-2012.

CONTEXT: Use of Immunization information systems (IISs) by providers can improve vaccination rates by identifying missed opportunities. However, provider reporting of children's vaccination histories to IISs remains suboptimal. OBJECTIVE: To assess factors associated with provider reporting to an IIS. DESIGN: Analysis of 2006-2012 National Immunization Survey (NIS) and NIS-Teen data. NIS and NIS-Teen are ongoing random-digit-dial telephone surveys of households with children and adolescents, respectively, followed by a mail survey to providers to obtain the patient's vaccination history. SETTING AND PARTICIPANTS: A total of 115 285 children aged 19 to 35 months and 83 612 adolescents aged 13 to 17 years and their immunization providers in the United States. MAIN OUTCOME MEASURES: The percentage of children and adolescents with 1 or more providers reporting to or obtaining vaccination information from their local IISs. Multivariable logistic regression was used to examine patient and provider factors associated with provider reporting to IISs and adjusted prevalence of children and adolescents with 1 or more providers reporting to IISs. RESULTS: In 2012, 79.4% of children and 77.4% of adolescents had 1 or more providers report any of their vaccination data to an IIS, and 41.9% of children and 51.5% of adolescents had providers who obtained any of their vaccination histories from an IIS. During 2006-2012, children and adolescents were more likely to have any of their vaccination data reported to an IIS if they received care from all public versus all private providers (children: 84.4% vs 69.6%, P < .0001; adolescents: 84.6% vs 66.4%, P < .0001), had 1 or more providers who ordered vaccines from a state or local health department (children: 76.7% vs 59.5%, P < .0001; adolescents: 77.0% vs 55.6%, P < .0001), or had 1 or more providers obtain vaccination information from the IIS (children: 86.1% vs 71.2%, P < .0001; adolescents: 83.7% vs 64.6%, P < .0001). CONCLUSIONS: Health department staff should target providers less likely to use IIS services, including private providers, and providers not ordering vaccines from health departments to ensure they use IIS services.

Vaccination Coverage Among Children in Kindergarten - United States, 2014-15 School Year.

State and local jurisdictions require children to be vaccinated before starting school to maintain high vaccination coverage and protect schoolchildren from vaccine-preventable diseases. State vaccination requirements, which include school vaccination and exemption laws and health department regulations, permit medical exemptions for students with a medical contraindication to receiving a vaccine or vaccine component and may allow nonmedical exemptions for religious reasons or philosophic beliefs. To monitor state and national vaccination coverage and exemption levels among children attending kindergarten, CDC analyzes school vaccination data collected by federally funded state, local, and territorial immunization programs. This report describes vaccination coverage estimates in 49 states and the District of Columbia (DC) and vaccination exemption estimates in 46 states and DC that reported the number of children with at least one exemption among kindergartners during the 2014-15 school year. Median vaccination coverage* was 94.0% for 2 doses of measles, mumps, and rubella (MMR) vaccine; 94.2% for the local requirements for diphtheria, tetanus, and acellular pertussis vaccine (DTaP); and 93.6% for 2 doses of varicella vaccine among the 39 states and DC with a 2-dose requirement. The median percentage of any exemptions† was 1.7%. Although statewide vaccination coverage among kindergartners was high during the 2014-15 school year, geographic pockets of low vaccination coverage and high exemption levels can place children at risk for vaccine-preventable diseases. Appropriate school vaccination coverage assessments can help immunization programs identify clusters of low coverage and develop partnerships with schools and communities to ensure that children are protected from vaccine-preventable diseases.

Influenza Vaccination Coverage Among Health Care Personnel--United States, 2014-15 Influenza Season.

The Advisory Committee on Immunization Practices recommends annual influenza vaccination for all health care personnel (HCP) to reduce influenza-related morbidity and mortality among both HCP and their patients and to decrease absenteeism among HCP. To estimate influenza vaccination coverage among U.S. HCP for the 2014­15 influenza season, CDC conducted an opt-in Internet panel survey of 1,914 HCP during March 31­April 15, 2015. Overall, 77.3% of HCP survey participants reported receiving an influenza vaccination during the 2014­15 season, similar to the 75.2% coverage among HCP reported for the 2013­14 season. Vaccination coverage was highest among HCP working in hospitals (90.4%) and lowest among HCP working in long-term care (LTC) settings (63.9%). By occupation, coverage was highest among pharmacists (95.3%) and lowest among assistants and aides (64.4%). Influenza vaccination coverage was highest among HCP who were required by their employer to be vaccinated (96.0%). Among HCP without an employer requirement for vaccination, coverage was higher for HCP working in settings where vaccination was offered on-site at no cost for 1 day (73.6%) or multiple days (83.9%) and lowest among HCP working in settings where vaccine was neither required, promoted, nor offered on-site (44.0%). Comprehensive vaccination strategies that include making vaccine available at no cost at the workplace along with active promotion of vaccination might help increase vaccination coverage among HCP and reduce the risk for influenza to HCP and their patients.

Influenza Vaccination Coverage Among Pregnant Women--United States, 2014-15 Influenza Season.

Pregnant women and infants are at increased risk for influenza-related complications and hospitalization. Influenza vaccination can reduce the risk for influenza-related illness among pregnant women and their infants. Since 2004, the Advisory Committee on Immunization Practices (ACIP) and the American College of Obstetricians and Gynecologists (ACOG) have recommended influenza vaccination for all women who are or will be pregnant during the influenza season, regardless of trimester of pregnancy. To assess influenza vaccination coverage among pregnant women during the 2014­15 influenza season, CDC analyzed data from an Internet panel survey conducted during March 31­April 6, 2015. Among 1,702 survey respondents who were pregnant at any time during October 2014­January 2015, 50.3% reported receiving influenza vaccination before or during pregnancy, similar to the reported coverage in the preceding season. Overall, 64.9% of respondents reported receiving a provider offer of influenza vaccination, 14.8% received a recommendation but no offer, and 20.3% received no recommendation. Vaccination coverage among these groups of women was 67.9%, 33.5%, and 8.5%, respectively. Reminder systems and standing orders that allow health care personnel other than the attending provider to assess vaccination status and administer vaccination, can help to ensure that influenza vaccination is recommended and offered to a pregnant woman at each provider visit to increase pregnant women's vaccination coverage.

Vaccination coverage among children in kindergarten - United States, 2013-14 school year.

State and local vaccination requirements for school entry are implemented to maintain high vaccination coverage and protect schoolchildren from vaccine-preventable diseases. Each year, to assess state and national vaccination coverage and exemption levels among kindergartners, CDC analyzes school vaccination data collected by federally funded state, local, and territorial immunization programs. This report describes vaccination coverage in 49 states and the District of Columbia (DC) and vaccination exemption rates in 46 states and DC for children enrolled in kindergarten during the 2013-14 school year. Median vaccination coverage was 94.7% for 2 doses of measles, mumps, and rubella (MMR) vaccine; 95.0% for varying local requirements for diphtheria, tetanus toxoid, and acellular pertussis (DTaP) vaccine; and 93.3% for 2 doses of varicella vaccine among those states with a 2-dose requirement. The median total exemption rate was 1.8%. High exemption levels and suboptimal vaccination coverage leave children vulnerable to vaccine-preventable diseases. Although vaccination coverage among kindergartners for the majority of reporting states was at or near the 95% national Healthy People 2020 targets for 4 doses of DTaP, 2 doses of MMR, and 2 doses of varicella vaccine, low vaccination coverage and high exemption levels can cluster within communities. Immunization programs might have access to school vaccination coverage and exemption rates at a local level for counties, school districts, or schools that can identify areas where children are more vulnerable to vaccine-preventable diseases. Health promotion efforts in these local areas can be used to help parents understand the risks for vaccine-preventable diseases and the protection that vaccinations provide to their children.

Influenza vaccination coverage among health care personnel--United States, 2013-14 influenza season.

The Advisory Committee on Immunization Practices recommends that all health care personnel (HCP) be vaccinated annually against influenza. Vaccination of HCP can reduce influenza-related morbidity and mortality among both HCP and their patients. To estimate influenza vaccination coverage among HCP during the 2013-14 season, CDC analyzed results of an opt-in Internet panel survey of 1,882 HCP conducted during April 1-16, 2014. Overall, 75.2% of participating HCP reported receiving an influenza vaccination during the 2013-14 season, similar to the 72.0% coverage among participating HCP reported in the 2012-13 season. Coverage was highest among HCP working in hospitals (89.6%) and lowest among HCP working in long-term care (LTC) settings (63.0%). By occupation, coverage was highest among physicians (92.2%), nurses (90.5%), nurse practitioners and physician assistants (89.6%), pharmacists (85.7%), and "other clinical personnel" (87.4%) compared with assistants and aides (57.7%) and nonclinical personnel (e.g., administrators, clerical support workers, janitors, and food service workers) (68.6%). HCP working in settings where vaccination was required had higher coverage (97.8%) compared with HCP working in settings where influenza vaccination was not required but promoted (72.4%) or settings where there was no requirement or promotion of vaccination (47.9%). Among HCP without an employer requirement for vaccination, coverage was higher for HCP working in settings where vaccination was offered on-site at no cost for 1 day (61.6%) or multiple days (80.4%) compared with HCP working in settings not offering free on-site vaccination (49.0%). Comprehensive vaccination strategies that include making vaccine available at no cost at the workplace along with active promotion of vaccination might be needed to increase vaccination coverage among HCP and minimize the risk for influenza to HCP and their patients.

Influenza vaccination coverage among pregnant women--United States, 2013-14 influenza season.

Pregnant women and infants are at increased risk for influenza-related complications and hospitalization. Influenza vaccination among pregnant women can reduce their risk for respiratory illness and reduce the risk for influenza in their infants aged <6 months. Since 2004, the Advisory Committee on Immunization Practices and the American College of Obstetricians and Gynecologists have recommended influenza vaccination for all women who are or will be pregnant during the influenza season, regardless of trimester. To assess influenza vaccination coverage among pregnant women during the 2013-14 influenza season, CDC analyzed data from an Internet panel survey conducted March 31-April 11, 2014. Among 1,619 survey respondents pregnant at any time during October 2013-January 2014, 52.2% reported vaccination before or during pregnancy (17.6% before and 34.6% during pregnancy), similar to the coverage in the preceding season. Overall, 65.1% of women reported receiving a clinician recommendation and offer of influenza vaccination, 15.1% received a clinician recommendation but no offer of vaccination, and 19.8% received no clinician recommendation or offer. Vaccination coverage among these women was 70.5%, 32.0%, and 9.7%, respectively. Continued efforts are needed to encourage clinicians to strongly recommend and offer influenza vaccination to their pregnant patients.

Schistosomiasis Seroprevalence among Children Aged 0-14 Years in Nigeria, 2018.

The first nationally representative, population-based study of schistosomiasis seroprevalence in Nigeria was conducted using blood samples and risk-factor data collected during the 2018 Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). Schistosomiasis seroprevalence was estimated by analyzing samples for reactivity to schistosome soluble egg antigen (SEA) in a multiplex bead assay; NAIIS survey data were assessed to identify potential risk factors for seropositivity. The SEA antibody data were available for 31,459 children aged 0 to 14 years. Overall seroprevalence was 17.2% (95% CI: 16.3-18.1%). Seropositive children were identified in every age group, including children < 5 years, and seroprevalence increased with increasing age (P < 0.0001). Several factors were associated with increased odds of seropositivity, including being a boy (odds ratio [OR] = 1.34, 95% CI: 1.24-1.45), living in a rural area (OR = 2.2, 95% CI: 1.9-2.5), and animal ownership (OR = 1.67, 95% CI: 1.52-1.85). Access to improved sanitation and drinking water sources were associated with decreased odds of seropositivity (OR = 0.52, 95% CI: 0.47-0.58 and OR = 0.53, 95% CI: 0.47-0.60, respectively) regardless of whether the child lived in a rural (sanitation: adjusted odds ratio [aOR] = 0.7, 95% CI: 0.6-0.8; drinking water: aOR = 0.7, 95% CI: 0.6-0.8) or urban area (sanitation: aOR = 0.6, 95% CI: 0.5-0.7; drinking water: aOR = 0.5, 95% CI: 0.4-0.6), highlighting the importance of these factors for schistosomiasis prevention and control. These results identified additional risk populations (children < 5 years) and a new risk factor (animal ownership) and could be used to monitor the impact of control programs.

Prevalence of influenza-specific vaccination hesitancy among adults in the United States, 2018.

BACKGROUND: The role of vaccine hesitancy on influenza vaccination is not clearly understood. Low influenza vaccination coverage in U.S. adults suggests that a multitude of factors may be responsible for under-vaccination or non-vaccination including vaccine hesitancy. Understanding the role of influenza vaccination hesitancy is important for targeted messaging and intervention to increase influenza vaccine confidence and uptake. The objective of this study was to quantify the prevalence of adult influenza vaccination hesitancy (IVH) and examine association of IVH beliefs with sociodemographic factors and early-season influenza vaccination. METHODS: A four-question validated IVH module was included in the 2018 National Internet Flu Survey. Weighted proportions and multivariable logistic regression models were used to identify correlates of IVH beliefs. RESULTS: Overall, 36.9% of adults were hesitant to receive an influenza vaccination; 18.6% expressed concerns about vaccination side effects; 14.8% personally knew someone with serious side effects; and 35.6% reported that their healthcare provider was not the most trusted source of information about influenza vaccinations. Influenza vaccination ranged from 15.3 to 45.2 percentage points lower among adults self-reporting any of the four IVH beliefs. Being female, age 18-49 years, non-Hispanic Black, having high school or lower education, being employed, and not having primary care medical home were associated with hesitancy. CONCLUSIONS: Among the four IVH beliefs studied, being hesitant to receiving influenza vaccination followed by mistrust of healthcare providers were identified as the most influential hesitancy beliefs. Two in five adults in the United States were hesitant to receive an influenza vaccination, and hesitancy was negatively associated with vaccination. This information may assist with targeted interventions, personalized to the individual, to reduce hesitancy and thus improve influenza vaccination acceptance.

Non-falciparum malaria infection and IgG seroprevalence among children under 15 years in Nigeria, 2018.

Plasmodium falciparum (Pf) is the dominant malaria parasite in Nigeria though P. vivax (Pv), P. ovale (Po), and P. malariae (Pm) are also endemic. Blood samples (n = 31,234) were collected from children aged 0-14 years during a 2018 nationwide HIV survey and assayed for Plasmodium antigenemia, Plasmodium DNA, and IgG against Plasmodium MSP1-19 antigens. Of all children, 6.6% were estimated to have Pm infection and 1.4% Po infection with no Pv infections detected. The highest household wealth quintile was strongly protective against infection with Pm (aOR: 0.11, 95% CI: 0.05-0.22) or Po (aOR= 0.01, 0.00-0.10). Overall Pm seroprevalence was 34.2% (95% CI: 33.3-35.2) with lower estimates for Po (12.1%, 11.6-12.5) and Pv (6.3%, 6.0-6.7). Pm seropositivity was detected throughout the country with several local government areas showing >50% seroprevalence. Serological and DNA indicators show widespread exposure of Nigerian children to Pm with lower rates to Po and Pv.

Dynamics of IgG antibody response against Plasmodium antigens among Nigerian infants and young children.

Background: Plasmodium falciparum malaria is a leading cause of child mortality in Nigeria. Neonates are born with maternal antibodies from placental transfer which may protect against malaria infection in the first months of life. The IgG dynamics of the transition from passively transferred antimalarial antibodies to actively acquired IgG from natural exposure have not been well elucidated. Methods: Blood samples collected during a 2018 Nigeria nationwide HIV/AIDS household survey were available for 9,443 children under 5 years of age, with a subset of infants under 2 months of age having maternal samples available (n=41). Samples were assayed for the P. falciparum HRP2 antigen and anti-malarial IgG antibodies. LOESS regression examined the dynamics in IgG response in the first 5 years of life. Correlation with maternal IgG levels was assessed for mother/child pairs. Results: Consistent decreases were observed in median IgG levels against all Plasmodium spp. antigen targets for the first months of life. At a population level, P. falciparum apical membrane antigen-1 (AMA1) and merozoite surface protein-1 19kD (PfMSP1) IgG decreased during the first 12 months of life before reaching a nadir, whereas IgGs to other targets only declined for the first 4 months of life. Seropositivity showed a similar decline with the lowest seropositivity against AMA1 and PfMSP1 at 10-12 months, though remaining above 50% during the first 2 years of life in higher transmission areas. No protective association was observed between IgG positivity and P. falciparum infection in infants. Maternal antibody levels showed a strong positive correlation with infant antibody levels for all P. falciparum antigens from birth to 2 months of age, but this correlation was lost by 6 months of age. Discussion: Maternally transferred anti-malarial IgG antibodies rapidly decline during the first 6 months of life, with variations among specific antigens and malaria transmission intensity. From 3-23 months of age, there was a wide range in IgG levels for the blood-stage antigens indicating high individual variation in antibody production as children are infected with malaria. Non-falciparum species-specific antigens showed similar patterns in waning immunity and correlation with paired mother's IgG levels compared to P. falciparum antigens.

Plasmodium falciparum infection prevalence among children aged 6-59 months from independent DHS and HIV surveys: Nigeria, 2018.

Prevalence estimates are critical for malaria programming efforts but generating these from non-malaria surveys is not standard practice. Malaria prevalence estimates for 6-59-month-old Nigerian children were compared between two national household surveys performed simultaneously in 2018: a Demographic and Health Survey (DHS) and the Nigeria HIV/AIDS Indicator and Impact Survey (NAIIS). DHS tested via microscopy (n = 8298) and HRP2-based rapid diagnostic test (RDT, n = 11,351), and NAIIS collected dried blood spots (DBS) which were later tested for histidine-rich protein 2 (HRP2) antigen (n = 8029). National Plasmodium falciparum prevalence was 22.6% (95% CI 21.2- 24.1%) via microscopy and 36.2% (34.6- 37.8%) via RDT according to DHS, and HRP2 antigenemia was 38.3% (36.7-39.9%) by NAIIS DBS. Between the two surveys, significant rank-order correlation occurred for state-level malaria prevalence for RDT (Rho = 0.80, p < 0.001) and microscopy (Rho = 0.75, p < 0.001) versus HRP2. RDT versus HRP2 positivity showed 24 states (64.9%) with overlapping 95% confidence intervals from the two independent surveys. P. falciparum prevalence estimates among 6-59-month-olds in Nigeria were highly concordant from two simultaneous, independently conducted household surveys, regardless of malaria test utilized. This provides evidence for the value of post-hoc laboratory HRP2 detection to leverage non-malaria surveys with similar sampling designs to obtain accurate P. falciparum estimates.

Comparison of one single-antigen assay and three multi-antigen SARS-CoV-2 IgG assays in Nigeria.

Objectives: Determining an accurate estimate of SARS-CoV-2 seroprevalence has been challenging in African countries where malaria and other pathogens are endemic. We compared the performance of one single-antigen assay and three multi-antigen SARS-CoV-2 IgG assays in a Nigerian population endemic for malaria. Methods: De-identified plasma specimens from SARS-CoV-2 RT-PCR positive, dried blood spot (DBS) SARS-CoV-2 RT-PCR positive, and pre-pandemic negatives were used to evaluate the performance of the four SARS-CoV-2 assays (Tetracore, SARS2MBA, RightSign, xMAP). Results: Results showed higher sensitivity with the multi-antigen (81% (Tetracore), 96% (SARS2MBA), 85% (xMAP)) versus the single-antigen (RightSign (64%)) SARS-CoV-2 assay. The overall specificities were 98% (Tetracore), 100% (SARS2MBA and RightSign), and 99% (xMAP). When stratified based on <15 days to ≥15 days post-RT-PCR confirmation, the sensitivities increased from 75% to 88.2% for Tetracore; from 93% to 100% for the SARS2MBA; from 58% to 73% for RightSign; and from 83% to 88% for xMAP. With DBS, there was no positive increase after 15-28 days for the three assays (Tetracore, SARS2MBA, and xMAP). Conclusion: Multi-antigen assays performed well in Nigeria, even with samples with known malaria reactivity, and might provide more accurate measures of COVID-19 seroprevalence and vaccine efficacy.

Parental Vaccine Hesitancy and Association With Childhood Diphtheria, Tetanus Toxoid, and Acellular Pertussis; Measles, Mumps, and Rubella; Rotavirus; and Combined 7-Series Vaccination.

INTRODUCTION: Parental vaccine hesitancy can be a barrier to routine childhood immunization and contribute to greater risk for vaccine-preventable diseases. This study examines the impact of parental vaccine hesitancy on childhood vaccination rates. METHODS: This study assessed the association of parental vaccine hesitancy on child vaccination coverage with ≥4 doses of diphtheria, tetanus toxoid, and acellular pertussis vaccine; ≥1 dose of measles, mumps, and rubella vaccine; up-to-date rotavirus vaccine; and combined 7-vaccine series coverage for a sample of children aged 19-35 months using data from the 2018 and 2019 National Immunization Survey-Child (N=7,645). Adjusted differences in multivariable analyses of vaccination coverage were estimated among vaccine hesitant and nonhesitant parents and population attributable risk fraction of hesitancy on undervaccination, defined as not being up to date for each vaccine. RESULTS: Almost a quarter of parents reported being vaccine hesitant, with the highest proportion of vaccine hesitancy among parents of children who are non-Hispanic Black (37.0%) or Hispanic (30.1%), mothers with a high school education or less (31.9%), and households living below the poverty level (35.6%). Childhood vaccination coverage for all vaccines was lower for children of hesitant than nonhesitant parents, and the population attributable fraction of hesitancy on undervaccination ranged from 15% to 25%, with the highest percentage for ≥1 dose of measles, mumps, and rubella vaccine. CONCLUSIONS: Parental vaccine hesitancy may contribute up to 25% of undervaccination among children aged 19-35 months. Implementation of strategies to address parental vaccine hesitancy is needed to improve vaccination coverage for children and minimize their risk of vaccine-preventable diseases.

Performance of SARS-CoV-2 Antigens in a Multiplex Bead Assay for Integrated Serological Surveillance of Neglected Tropical and Other Diseases.

Serosurveillance can provide estimates of population-level exposure to infectious pathogens and has been used extensively during the COVID-19 pandemic. Simultaneous, serological testing for multiple pathogens can be done using bead-based immunoassays to add value to disease-specific serosurveys. We conducted a validation of four SARS-CoV-2 antigens-full-length spike protein, two receptor binding domain proteins, and the nucleocapsid protein-on our existing multiplex bead assay (MBA) for enteric diseases, malaria, and vaccine preventable diseases. After determining the optimal conditions for coupling the antigens to microsphere beads, the sensitivity and specificity of the assay were determined on two instruments (Luminex-200 and MAGPIX) when testing singly (monoplex) versus combined (multiplex). Sensitivity was assessed using plasma from 87 real-time reverse transcription polymerase chain reaction (rRT-PCR) positive persons collected in March-May of 2020 and ranged from 94.3% to 96.6% for the different testing conditions. Specificity was assessed using 98 plasma specimens collected prior to December 2019 and plasma from 19 rRT-PCR negative persons and ranged from 97.4% to 100%. The positive percent agreement was 93.8% to 97.9% using 48 specimens collected > 21 days post-symptom onset, while the negative percent agreement was ≥ 99% for all antigens. Test performance was similar using monoplex or multiplex testing. Integrating SARS-CoV-2 serology with other diseases of public health interest could add significant value to public health programs that have suffered severe programmatic setbacks during the COVID-19 pandemic.