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A signature remains elusive of naturally-acquired immunity against Plasmodium falciparum. We identified P. falciparum in a 14-month cohort of 239 people in Kenya, genotyped at immunogenic parasite targets expressed in the pre-erythrocytic (circumsporozoite protein, CSP) and blood (apical membrane antigen 1, AMA-1) stages, and classified into epitope type based on variants in the DV10, Th2R, and Th3R epitopes in CSP and the c1L region of AMA-1. Compared to asymptomatic index infections, symptomatic malaria was associated with reduced reinfection by parasites bearing homologous CSP-Th2R (adjusted hazard ratio [aHR]:0.63; 95% CI:0.45-0.89; p = 0.008) CSP-Th3R (aHR:0.71; 95% CI:0.52-0.97; p = 0.033), and AMA-1 c1L (aHR:0.63; 95% CI:0.43-0.94; p = 0.022) epitope types. The association of symptomatic malaria with reduced hazard of homologous reinfection was strongest for rare epitope types. Symptomatic malaria provides more durable protection against reinfection with parasites bearing homologous epitope types. The phenotype represents a legible molecular epidemiologic signature of naturally-acquired immunity by which to identify new antigen targets.

Under-screened women are more likely to be diagnosed with invasive cervical cancer at later stages and have worse survival outcomes. Under- or un-insured women, low-income women, and minoritized groups face barriers to screening. Intention to screen is an indicator of future screening behavior, yet is understudied among low-income, under-screened women. Participants were 710 low-income, uninsured or publicly insured women ages 25-64 years in North Carolina who were not up to date on cervical cancer screening according to national guidelines. Participants were asked about barriers to screening and intention to screen. We estimated reported barriers to cervical cancer screening stratified by race and ethnicity (categorized as White, Black, and Hispanic) and assessed predictors of intention to screen. Sixty-one percent of all participants reported 5 or more barriers to screening. The most commonly reported reasons for not getting screened were lack of insurance (White: 71%, Black: 62%, Hispanic/Latina: 63%) and cost (White: 55%, Black: 44%, Hispanic/Latina: 61%). Women were more likely to have an intention to screen if they reported "it was not hard to get screening" (OR: 1.47 (1.00, 2.15)). Older women reported being less likely to intend to screen. Black women reported being more likely to intend to screen than White women. Lack of health insurance and cost were frequently reported barriers to cervical cancer screening. Increasing knowledge of affordable clinics and expanding access to Medicaid may reduce barriers and increase cervical cancer screening uptake.

Background: Underscreened, low-income, and uninsured or publicly insured women in the United States bear a greater burden of cervical cancer morbidity and mortality and may face unique barriers that preclude screening adherence. Methods: Participants were 710 My Body My Test-3 clinical trial participants who were publicly insured or uninsured with incomes ≤250% of the U.S. Federal Poverty Level, aged 25-64 years, and not up to date on cervical cancer screening as per national guidelines. Using Health Belief Model constructs, we assessed screening-related knowledge, perceptions, and behaviors-overall and stratified by race and ethnicity-and estimated associations with past-year attempted screening using multivariable regression models. Results: Overall, knowledge was low about the human papillomavirus, purpose of a Pap test, and recommended screening interval. Perceived severity of cervical cancer was high (3.63 on a 4-point scale). Black and Latina/Hispanic women were more likely to perceive screening as lowering their risk of cervical cancer than White women. Black women reported lower perceived risk of cervical cancer compared with White women ( p  = 0.03), but Black women were more likely to have sought screening in the past year ( p  = 0.01). Having at least three doctor visits in the past year was associated with a screening attempt. Greater perceived risk of cervical cancer, more positive perceptions of screening, and feeling more nervousness about screening were also associated with a screening attempt (all p  < 0.05). Conclusions: Addressing knowledge gaps and misconceptions about cervical cancer screening and leveraging positive perceptions of screening may improve screening uptake and adherence among diverse underscreened U.S. women. Clinical Trial Registration Number: NCT02651883.