Behavioral and social drivers of COVID-19 vaccination initiation in the US: a longitudinal study March─ October 2021.

Many studies have examined behavioral and social drivers of COVID-19 vaccination initiation, but few have examined these drivers longitudinally. We sought to identify the drivers of COVID-19 vaccination initiation using the Behavioral and Social Drivers of Vaccination (BeSD) Framework. Participants were a nationally-representative sample of 1,563 US adults who had not received a COVID-19 vaccine by baseline. Participants took surveys online at baseline (spring 2021) and follow-up (fall 2021). The surveys assessed variables from BeSD Framework domains (i.e., thinking and feeling, social processes, and practical issues), COVID-19 vaccination initiation, and demographics at baseline and follow-up. Between baseline and follow-up, 65% of respondents reported initiating COVID-19 vaccination. Vaccination intent increased from baseline to follow-up (p < .01). Higher vaccine confidence, more positive social norms towards vaccination, and receiving vaccine recommendations at baseline predicted subsequent COVID-19 vaccine initiation (all p < .01). Among factors assessed at follow-up, social responsibility and vaccine requirements had the greatest associations with vaccine initiation (all p < .01). Baseline vaccine confidence, social norms, and vaccination recommendations were associated with subsequent vaccine initiation, all of which could be useful targets for behavioral interventions. Furthermore, interventions that highlight social responsibility to vaccinate or promote vaccination requirements could also be beneficial.

Barriers to Cervical Cancer Screening by Sexual Orientation Among Low-Income Women in North Carolina.

We sought to examine cervical cancer screening barriers by sexual orientation among low-income women in North Carolina. The MyBodyMyTest-3 Trial recruited low-income women (< 250% of federal poverty level) aged 25-64 years who were 1+ year overdue for cervical cancer screening. We compared perceptions of cervical cancer screening among those who self-identified as lesbian, gay, bisexual, or queer (LGBQ; n = 70) to straight/heterosexual women (n = 683). For both LGBQ and straight respondents, the greatest barriers to screening were lack of health insurance (63% and 66%) and cost (49% and 50%). LGBQ respondents were more likely than straight respondents to report forgetting to screen (16% vs. 8%, p = .05), transportation barriers (10% vs. 2%, p = .001), and competing mental or physical health problems (39% vs. 27%, p = .10). Addressing access remains important for improving cervical cancer screening among those under-screened. For LGBQ women, additional attention may be needed for reminders, co-occurring health needs, and transportation barriers.

Can AnatomicalTerms.info with its synonyms and succinct open definitions be a solution to address variations in usage of anatomical terminology?

Anatomy, the study of human structure, is foundational to medicine. Its language has a long history, with contributions from authors hailing from diverse cultures and countries, adhering to various scientific traditions, speaking different languages, and practicing medicine across a wide gamut of specialties. The resultant disparity in terms provides challenges both for students in learning and for interdisciplinary communication. We report here on a user-friendly look-up web site, "AnatomicalTerms.info" that links a Terminologica Anatomica term to alternative terms in usage: synonyms, polysemes, eponyms, homonyms, and terms in other languages. Accompanying open-source definitions are generated with the help of "Definition Machine" software, that supports creating the most concise and accessible definitions for anatomical terms, eschewing superfluous description, thus reducing cognitive load of learners of anatomy looking up terms. AnatomicalTerms.info is a readily accessible online source for both the authoritative and alternatively used terms that can accurately cross-reference and/or disambiguate anatomical structures across disciplinary and cultural divides. As such, it can serve as a useful educational and clinical resource that is also flexibly open to additions and expansion as anatomical and clinical needs dictate.

Crimean-Congo Hemorrhagic Fever Survivors Elicit Protective Non-Neutralizing Antibodies that Target 11 Overlapping Regions on Viral Glycoprotein GP38.

Crimean-Congo hemorrhagic fever virus can cause lethal disease in humans yet there are no approved medical countermeasures. Viral glycoprotein GP38, unique to Nairoviridae, is a target of protective antibodies, but extensive mapping of the human antibody response to GP38 has not been previously performed. Here, we isolated 188 GP38-specific antibodies from human survivors of infection. Competition experiments showed that these antibodies bind across five distinct antigenic sites, encompassing eleven overlapping regions. Additionally, we reveal structures of GP38 bound with nine of these antibodies targeting different antigenic sites. Although GP38-specific antibodies were non-neutralizing, several antibodies were found to have protection equal to or better than murine antibody 13G8 in two highly stringent rodent models of infection. Together, these data expand our understanding regarding this important viral protein and inform the development of broadly effective CCHFV antibody therapeutics.

Milk to mucus: How B. fragilis colonizes the gut.

Human milk oligosaccharide (HMO) consumption by the infant microbiota is positively associated with immune health. In this issue of Cell Host & Microbe, Buzun et al. report a mechanism for HMO digestion by Bacteroides fragilis and demonstrate how the same pathway works on intestinal mucus to establish long-term gut residency.

Identifying Healthcare Professionals With Lower Human Papillomavirus (HPV) Vaccine Recommendation Quality: A Systematic Review.

PURPOSE: Strengthening healthcare professionals' (HCPs) communication is an evidence-based approach to increasing human papillomavirus (HPV) vaccine uptake among adolescents. To better target future interventions, we sought to synthesize evidence on HCP subgroups who most need to improve their HPV vaccine recommendation quality. METHODS: We searched five databases for quantitative studies published from 2012 to 2022 on HPV vaccine recommendation quality, including recommendation consistency and strength, for United States adolescents. Two coders independently abstracted data from each eligible study, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We summarized variation in recommendation quality by clinical and HCP characteristics. RESULTS: The 28 eligible studies indicated that relatively low proportions of HCPs used higher-quality recommendation practices (median: 61% across 30 measures) and that recommendation quality varied across HCP subgroups. The most consistent findings were that more pediatric HCPs used higher-quality recommendations than family medicine HCPs (8 of 11 studies, 2-60 percentage point difference) and that HPV-related knowledge was associated with higher recommendation quality (four of seven studies). Most studies observed no differences in recommendation quality by clinical role (e.g., provider vs. nurse) or HCP demographics (e.g., gender, age, race/ethnicity). DISCUSSION: Studies suggest a substantial need to improve HCPs' recommendation quality, with opportunities for targeting future interventions.

Plant-based diets and the gut microbiome: findings from the Baltimore Longitudinal Study of Aging.

BACKGROUND: Mounting evidence indicates that although some plant-based diets are healthful, others are not. Changes in the gut microbiome and microbiome-dependent metabolites, such as trimethylamine N-oxide (TMAO), may explain differential health effects of plant-based diets. However, human data are sparse on whether qualitatively distinct types of plant-based diets differentially affect gut microbiome diversity, composition, particularly at the species level, and/or metabolites. OBJECTIVES: We aimed to examine cross-sectional associations of different plant-based indices with adult gut microbiome diversity, composition, and the metabolite TMAO. METHODS: We studied 705 adults in the Baltimore Longitudinal Study of Aging with data for diet, fecal microbiome (shotgun metagenomic sequencing), and key covariates. We derived healthful plant-based diet index (hPDI) and unhealthful plant-based diet index (uPDI) using data from food frequency questionnaires. We examined plant-based diet indices with microbiome α-diversity (richness and evenness measures), ß-diversity (Bray-Curtis and UniFrac measures), composition (species level), and plasma TMAO. We used regression models to determine associations before and after adjustment for age, sex, education, physical activity, smoking status, body mass index, and total energy intake. RESULTS: The analytic sample (mean age, 71.0 years, SD = 12.8 years) comprised 55.6% female and 67.5% non-Hispanic White participants. hPDI was positively and uPDI negatively associated with microbiome α-diversity, driven by microbial evenness (Pielou P < 0.05). hPDI was also positively associated with relative abundance of 3 polysaccharide-degrading bacterial species (Faecalibacterium prausnitzii, Eubacterium eligens, and Bacteroides thetaiotaomicron) and inversely associated with 6 species (Blautia hydrogenotrophica, Doreasp CAG 317, Eisenbergiella massiliensis, Sellimonas intestinalis, Blautia wexlerae, and Alistipes shahii). Furthermore, hPDI was inversely associated with TMAO. Associations did not differ by age, sex, or race. CONCLUSIONS: Greater adherence to a healthful plant-based diet is associated with microbiome features that have been linked to positive health; adherence to an unhealthful plant-based diet has opposing or null associations with these features.

Protocolized Natriuresis-Guided Decongestion Improves Diuretic Response: The Multicenter ENACT-HF Study.

BACKGROUND: The use of urinary sodium to guide diuretics in acute heart failure is recommended by experts and the most recent European Society of Cardiology guidelines. However, there are limited data to support this recommendation. The ENACT-HF study (Efficacy of a Standardized Diuretic Protocol in Acute Heart Failure) investigated the feasibility and efficacy of a standardized natriuresis-guided diuretic protocol in patients with acute heart failure and signs of volume overload. METHODS: ENACT-HF was an international, multicenter, open-label, pragmatic, 2-phase study, comparing the current standard of care of each center with a standardized diuretic protocol, including urinary sodium to guide therapy. The primary end point was natriuresis after 1 day. Secondary end points included cumulative natriuresis and diuresis after 2 days of treatment, length of stay, and in-hospital mortality. All end points were adjusted for baseline differences between both treatment arms. RESULTS: Four hundred one patients from 29 centers in 18 countries worldwide were included in the study. The natriuresis after 1 day was significantly higher in the protocol arm compared with the standard of care arm (282 versus 174 mmol; adjusted mean ratio, 1.64; P<0.001). After 2 days, the natriuresis remained higher in the protocol arm (538 versus 365 mmol; adjusted mean ratio, 1.52; P<0.001), with a significantly higher diuresis (5776 versus 4381 mL; adjusted mean ratio, 1.33; P<0.001). The protocol arm had a shorter length of stay (5.8 versus 7.0 days; adjusted mean ratio, 0.87; P=0.036). In-hospital mortality was low and did not significantly differ between the 2 arms (1.4% versus 2.0%; P=0.852). CONCLUSIONS: A standardized natriuresis-guided diuretic protocol to guide decongestion in acute heart failure was feasible, safe, and resulted in higher natriuresis and diuresis, as well as a shorter length of stay.

Bayesian kernel machine regression for count data: modelling the association between social vulnerability and COVID-19 deaths in South Carolina.

The COVID-19 pandemic created an unprecedented global health crisis. Recent studies suggest that socially vulnerable communities were disproportionately impacted, although findings are mixed. To quantify social vulnerability in the US, many studies rely on the Social Vulnerability Index (SVI), a county-level measure comprising 15 census variables. Typically, the SVI is modelled in an additive manner, which may obscure non-linear or interactive associations, further contributing to inconsistent findings. As a more robust alternative, we propose a negative binomial Bayesian kernel machine regression (BKMR) model to investigate dynamic associations between social vulnerability and COVID-19 death rates, thus extending BKMR to the count data setting. The model produces a 'vulnerability effect' that quantifies the impact of vulnerability on COVID-19 death rates in each county. The method can also identify the relative importance of various SVI variables and make future predictions as county vulnerability profiles evolve. To capture spatio-temporal heterogeneity, the model incorporates spatial effects, county-level covariates, and smooth temporal functions. For Bayesian computation, we propose a tractable data-augmented Gibbs sampler. We conduct a simulation study to highlight the approach and apply the method to a study of COVID-19 deaths in the US state of South Carolina during the 2021 calendar year.

Mother's age at menarche is associated with odds of preterm delivery: A case-control study.

OBJECTIVE: There is a secular trend towards earlier age of menarche in the US and globally. Earlier age at menarche (AAM) has been associated with metabolic disorders that increase risk for preterm delivery (PTD), yet no studies in the US have investigated whether AAM influences risk of PTD. This study tested the hypothesis that AAM is associated with PTD. DESIGN: A case-control study. SETTING: The Boston Medical Center (BMC) in Boston, Massachusetts. POPULATION OR SAMPLE: 8264 mother-newborn dyads enrolled at birth at BMC between 1998 and 2019, of which 2242 mothers had PTD (cases) and 6022 did not have PTD (controls). METHODS: Multivariable-adjusted logistic regression models and restricted cubic splines were used to examine the association between AAM and risk of PTD. The combined impact of AAM and age at delivery on the risk of PTD was also examined. MAIN OUTCOME MEASURES: Preterm delivery and gestational age (GA) was defined by maternal last menstrual period and early ultrasound documented in medical records. RESULTS: Maternal age at delivery was 28.1 ± 6.5 years and AAM was 12.85 ± 1.86 years. Multivariable-adjusted cubic spline suggested an inverse dose-response association of AAM with odds of PTD and, consistently, a positive association with GA. A 1-year earlier AAM was associated with 5% (95% CI 2%-8%) higher odds of PTD, after adjustment for maternal year of birth, parity, maternal place of birth, education, smoking status and Mediterranean-style diet score. The association between AAM and PTD was stronger among older mothers whose age at delivery was ≥35 years. CONCLUSIONS: Earlier AAM is associated with higher odds for PTD, and this association is stronger among women at advanced reproductive age.

Breastfeeding and less healthy beverage intake during the first year of life.

BACKGROUND AND OBJECTIVES: Breastfeeding during infancy is associated with healthier beverage consumption later in childhood, but little is known about this relation during infancy. This was a longitudinal study of breastfeeding and less healthy beverage consumption during the first year of life, in a birth cohort study conducted 2013-2018 in the Southeastern United States (n = 666). METHODS: We estimated monthly rates of 100% juice and sugar-sweetened beverage (SSB) consumption comparing infants who were exclusively or partially breastfed, versus those who were not, in multivariable adjusted models. RESULTS: Mothers had a median age of 26.5 years, 71% identified as Black/African-American, and 61% reported household incomes <$20 000/year. The prevalence of any breastfeeding during the first month was 78.2% and 18.7% at month 12. By age 12 months, infants consumed juice a mean (SD) 9.1 (10.1) times per week and SSBs 3.6 (9.5) times per week. Breastfed infants had a 38% lower incidence rate of weekly juice consumption (95% CI 52%, 15%, p = 0.003) and a 57% lower incidence rate of weekly SSB consumption (95% CI 76%, 22%, p = 0.006), compared with infants who were not breastfed. CONCLUSIONS: Research on early-life correlates of dietary health should focus on the earliest beverages, given evidence that consumption of obesogenic beverages may begin prior to age 1 year.

Impact of visit characteristics on intention to recommend HPV vaccine: An experiment with US health care professionals.

OBJECTIVE: Presumptive recommendations that assume parents want to vaccinate can increase human papillomavirus (HPV) vaccine uptake. We sought to examine how visit characteristics affect health care professionals' (HCPs) intention to use this evidence-based recommendation style. METHODS: In 2022, we conducted an online experiment with 2527 HCPs who had a role in adolescent vaccination in the United States. Participants read 1 of 8 randomly assigned vignettes about a well-child visit. Using a 2 × 2 × 2 between-subjects factorial design, the vignettes varied the following visit characteristics: patient age (9 vs. 12-year-old), prior parental vaccine refusal (yes vs. no), and time pressure on the HCP (low vs. high). HCPs reported on their intention to use a presumptive HPV vaccine recommendation, as well as on related attitudes, subjective norms, and self-efficacy. Analyses used 3-way analysis of variance and parallel mediation. RESULTS: Participants were pediatricians (26%), family/general medicine physicians (22%), advanced practitioners (24%), and nursing staff (28%). Overall, about two-thirds of HCPs (64%) intended to use a presumptive recommendation. Intentions were higher for older children (b = 0.23) and parents without prior vaccine refusal (b = 0.39, both p < 0.001). Time pressure had no main effect or interactions. HCPs' attitudes and self-efficacy partially mediated effects of patient age and prior vaccine refusal (range of b = 0.04-0.28, all p < 0.05). CONCLUSION: To better support visits with younger children and parents who have refused vaccines, HCPs may need more training for making presumptive recommendations for HPV vaccine. Reinforcing positive attitudes and self-efficacy can help HCPs adopt this evidence-based recommendation style.

Addressing COVID-19 vaccine hesitancy in rural community pharmacies: a protocol for a stepped wedge randomized clinical trial.

BACKGROUND: Uptake of COVID-19 vaccines remains problematically low in the USA, especially in rural areas. COVID-19 vaccine hesitancy is associated with lower uptake, which translates to higher susceptibility to SARS-CoV-2 variants in communities where vaccination coverage is low. Because community pharmacists are among the most accessible and trusted health professionals in rural areas, this randomized clinical trial will examine implementation strategies to support rural pharmacists in delivering an adapted evidence-based intervention to reduce COVID-19 vaccine hesitancy. METHODS: We will use an incomplete stepped wedge trial design in which we will randomize 30 rural pharmacies (unit of analysis) to determine the effectiveness and incremental cost-effectiveness of a standard implementation approach (consisting of online training that describes the vaccine hesitancy intervention, live webinar, and resource website) compared to adding on a virtual facilitation approach (provided by a trained facilitator in support of the delivery of the vaccine hesitancy counseling intervention by pharmacists). The intervention (ASORT) has been adapted from an evidence-based vaccine communication intervention for HPV vaccines through a partnership with rural pharmacies in a practice-based research network in seven southern US states. ASORT teaches pharmacists how to identify persons eligible for COVID-19 vaccination (including a booster), solicit and address vaccine concerns in a non-confrontational way, recommend the vaccine, and repeat the steps later if needed. The primary trial outcome is fidelity to the ASORT intervention, which will be determined through ratings of recordings of pharmacists delivering the intervention. The secondary outcome is the effectiveness of the intervention, determined by rates of patients who agree to be vaccinated after receiving the intervention. Other secondary outcomes include feasibility, acceptability, adoption, reach, and cost. Cost-effectiveness and budget impact analyses will be conducted to maximize the potential for future dissemination and sustainability. Mixed methods will provide triangulation, expansion, and explanation of quantitative findings. DISCUSSION: This trial contributes to a growing evidence base on vaccine hesitancy interventions and virtual-only facilitation of evidenced-based practices in community health settings. The trial will provide the first estimate of the relative value of different implementation strategies in pharmacy settings. TRIAL REGISTRATION: NCT05926544 (clinicaltrials.gov); 07/03/2023.

Associations of Plastic Bottle Exposure with Infant Growth, Fecal Microbiota, and Short-Chain Fatty Acids.

BACKGROUND/OBJECTIVES: Murine models show that plastics, via their chemical constituents (e.g., phthalates), influence microbiota, metabolism, and growth. However, research on plastics in humans is lacking. Here, we examine how the frequency of plastic bottle exposure is associated with fecal microbiota, short-chain fatty acids (SCFAs), and anthropometry in the first year of life. SUBJECTS/METHODS: In 442 infants from the prospective Nurture birth cohort, we examined the association of frequency of plastic bottle feeding at 3 months with anthropometric outcomes (skinfolds, length-for-age, and weight-for-length) at 12 months of age and growth trajectories between 3 and 12 months. Furthermore, in a subset of infants (n = 70) that contributed fecal samples at 3 months and 12 months of age, we examined plastic bottle frequency in relation to fecal microbiota composition and diversity (measured by 16S rRNA gene sequencing of V4 region), and fecal SCFA concentrations (quantified using gas chromatography mass spectrometry). RESULTS: At 3 months, 67.6% of infants were plastic bottle fed at every feeding, 15.4% were exclusively breast milk fed, and 48.9% were exclusively formula fed. After adjustment for potential confounders, infants who were plastic bottle fed less than every feeding compared to those who were plastic bottle fed at every feeding at 3 months did not show differences in anthropometry over the first 12 months of life, save for lower length-for-age z-score at 12 months (adjusted ß = -0.45, 95% CI: -0.76, -0.13). Infants who were plastic bottle fed less than every feeding versus every feeding had lower fecal microbiota alpha diversity at 3 months (mean difference for Shannon index: -0.59, 95% CI: -0.99, -0.20) and lower isovaleric acid concentration at 3 months (mean difference: -2.12 µmol/g, 95% CI: -3.64, -0.60), but these results were attenuated following adjustment for infant diet. Plastic bottle frequency was not strongly associated with microbiota diversity or SCFAs at 12 months after multivariable adjustment. Frequency of plastic bottle use was associated with differential abundance of some bacterial taxa, however, significance was not consistent between statistical approaches. CONCLUSIONS: Plastic bottle frequency at 3 months was not strongly associated with measures of adiposity or growth (save for length-for-age) over the first year of life, and while plastic bottle use was associated with some features of fecal microbiota and SCFAs in the first year, these findings were attenuated in multivariable models with infant diet. Future research is needed to assess health effects of exposure to other plastic-based products and objective measures of microplastics and plastic constituents like phthalates.

Opportunities for Examining Child Health Impacts of Early-Life Nutrition in the ECHO Program: Maternal and Child Dietary Intake Data from Pregnancy to Adolescence.

Background: Longitudinal measures of diet spanning pregnancy through adolescence are needed from a large, diverse sample to advance research on the effect of early-life nutrition on child health. The Environmental influences on Child Health Outcomes (ECHO) Program, which includes 69 cohorts, >33,000 pregnancies, and >31,000 children in its first 7-y cycle, provides such data, now publicly available. Objectives: This study aimed to describe dietary intake data available in the ECHO Program as of 31 August, 2022 (end of year 6 of Cycle 1) from pregnancy through adolescence, including estimated sample sizes, and to highlight the potential for future analyses of nutrition and child health. Methods: We identified and categorized ECHO Program dietary intake data, by assessment method, participant (pregnant person or child), and life stage of data collection. We calculated the number of maternal-child dyads with dietary data and the number of participants with repeated measures. We identified diet-related variables derived from raw dietary intake data and nutrient biomarkers measured from biospecimens. Results: Overall, 66 cohorts (26,941 pregnancies, 27,103 children, including 22,712 dyads) across 34 US states/territories provided dietary intake data. Dietary intake assessments included 24-h recalls (1548 pregnancies and 1457 children), food frequency questionnaires (4902 and 4117), dietary screeners (8816 and 23,626), and dietary supplement use questionnaires (24,798 and 26,513). Repeated measures were available for ∼70%, ∼30%, and ∼15% of participants with 24-h recalls, food frequency questionnaires, and dietary screeners, respectively. The available diet-related variables describe nutrient and food intake, diet patterns, and breastfeeding practices. Overall, 17% of participants with dietary intake data had measured nutrient biomarkers. Conclusions: ECHO cohorts have collected longitudinal dietary intake data spanning pregnancy through adolescence from a geographically, socioeconomically, and ethnically diverse US sample. As data collection continues in Cycle 2, these data present an opportunity to advance the field of nutrition and child health.

Nitrogen thermometry in an inductively coupled plasma torch using broadband nanosecond coherent anti-Stokes Raman scattering.

The development of atmospheric hypersonic flight and re-entry capabilities requires the characterization of the thermo-chemical state of representative test environments. This study demonstrates the usage of multiplex nanosecond N 2 coherent anti-Stokes Raman scattering (CARS) to measure temperatures in an atmospheric, high-temperature (>6000K), air plasma plume, generated by an inductively coupled plasma torch. These are some of the highest temperatures ever accessed via gas-phase CARS, to our knowledge. Temperatures of N 2 in the equilibrium plasma plume are determined via theoretical fits to measured CARS spectra. We discuss the practical implementation of CARS at very high temperatures, including the scaling of the N 2 CARS signal strength from 300 to 6700 K, where the expected peak signal from the high-temperature plasma torch gases is two orders of magnitude less than commonly encountered in combustion environments. An intensified CCD camera enables single-laser-shot detection at temperatures as high as 6200 K, by increasing sensitivity and providing a time gate against intense background luminosity. We also discuss the impacts of unwanted two-beam CARS contributions from outside the nominal three-beam measurement volume. We present mean axial and radial temperature profiles, as well as time-series data derived from both single-laser-shot and accumulated CARS spectra. The single-laser-shot precision is 1.7%-2.6% at temperatures of 3500 to 6200 K. The presented results pave the way for the use of CARS at very high temperatures and the measurement of spatially resolved interface processes in high-enthalpy flows.

Effects of Modified Risk Tobacco Product Claims on Consumer Responses.

BACKGROUND: US tobacco manufacturers can seek authorization from FDA to market products using modified risk tobacco product (MRTP) claims. To inform regulatory decisions, we examined the impact of MRTP claim specificity and content, including whether the claims produced halo effects (i.e., inferring health benefits beyond what is stated). METHODS: Participants were 3,161 US adult cigarette smokers. Using a 2 (general vs. specific) × 2 (risk vs. exposure) plus independent control design, we randomized participants to view one message from these conditions: general risk claim (e.g., "tobacco-related diseases"), general exposure claim (e.g., "harmful chemicals"), specific risk claim (e.g., "lung cancer"), specific exposure claim (e.g., "arsenic"), or control. Claims described benefits of completely switching from cigarettes to the heated tobacco product IQOS. RESULTS: MRTP claims of any sort elicited higher willingness to try IQOS relative to control (d=0.09, p=0.043). Claims also elicited lower perceived risk of disease and exposure to harmful chemicals for completely switching from cigarettes to IQOS (d=-0.32 and-0.31) and partially switching (d=-0.25 and=-0.26; all p<0.05). Relative to specific MRTP claims, general MRTP claims led to lower perceived risk and exposure for complete switching (d=-0.13 and d=-0.16) and partial switching (d=-0.14 and d=-0.12; all p<0.05). Risk and exposure MRTP claims had similar effects (all p>0.05). DISCUSSION: MRTP claims led to lower perceived risk and exposure, and higher willingness to try IQOS. General claims elicited larger effects than specific claims. MRTP claims also promoted unintended halo effects (e.g., lower perceived risk of disease and chemical exposure for partial switching). IMPLICATIONS: We found evidence that MRTP claims promoted health halo effects. In light of these findings, FDA should require research on halo effects prior to authorization. Further, if an MRTP claim is authorized, FDA should require tobacco manufacturers to conduct post-market surveillance of how the claim affects consumer understanding, including partial switching perceived risk and exposure beliefs, as well as monitoring of dual-use behaviors.