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In a phase 1 randomized, single-center clinical trial, inactivated influenza virus vaccine delivered through dissolvable microneedle patches (MNPs) was found to be safe and immunogenic. Here, we compare the humoral and cellular immunologic responses in a subset of participants receiving influenza vaccination by MNP to the intramuscular (IM) route of administration. We collected serum, plasma, and peripheral blood mononuclear cells in 22 participants up to 180 days post-vaccination. Hemagglutination inhibition (HAI) titers and antibody avidity were similar after MNP and IM vaccination, even though MNP vaccination used a lower antigen dose. MNPs generated higher neuraminidase inhibition (NAI) titers for all three influenza virus vaccine strains tested and triggered a larger percentage of circulating T follicular helper cells (CD4 + CXCR5 + CXCR3 + ICOS + PD-1+) compared to the IM route. Our study indicates that inactivated influenza virus vaccination by MNP produces humoral and cellular immune response that are similar or greater than IM vaccination.

Molecular detection of dengue virus (DENV) RNA from serum or plasma provides an accurate acute-phase diagnostic (< 7 days after symptom onset). Detection may be prolonged in whole blood, although data are limited. We tested for DENV by real-time reverse transcription–PCR in 345 paired acute-phase plasma and whole blood samples from individuals with a Flavivirus-like illness in southwestern Guatemala. In 18/18 cases with detectable DENV RNA in plasma, whole blood samples were positive and yielded similar cycle threshold values. In seven individuals with convalescent samples obtained 2–3 weeks later, DENV RNA remained detectable in whole blood but not plasma. In three additional cases, DENV RNA was only detectable in whole blood at the acute visit. In two cases, whole blood detection was linked to a virologically confirmed DENV infection 6–11 weeks earlier. Whole blood DENV RNA detection is sensitive for acute dengue infection and may remain positive for weeks to months.

Antibody cross-reactivity confounds testing for dengue virus (DENV) and Zika virus (ZIKV). We evaluated anti-DENV and anti-ZIKV IgG detection using a multiplex serological platform (the pGOLD assay, Nirmidas, Palo Alto, CA) in patients from the Asunción metropolitan area in Paraguay, which experiences annual DENV outbreaks but has reported few autochthonous ZIKV infections. Acute-phase sera were tested from 77 patients who presented with a suspected arboviral illness from January to May 2018. Samples were tested for DENV and ZIKV RNA by real-time reverse transcription-PCR, and for DENV nonstructural protein 1 with a lateral-flow immunochromatographic test. Forty-one patients (51.2%) had acute dengue; no acute ZIKV infections were detected. Sixty-five patients (84.4%) had anti–DENV-neutralizing antibodies by focus reduction neutralization testing (FRNT50). Qualitative detection with the pGOLD assay demonstrated good agreement with FRNT50 (kappa = 0.74), and quantitative results were highly correlated between methods (P < 0.001). Only three patients had anti–ZIKV-neutralizing antibodies at titers of 1:55–1:80, and all three had corresponding DENV-neutralizing titers > 1:4,000. Hospitalized dengue cases had significantly higher anti-DENV IgG levels (P < 0.001). Anti-DENV IgG results from the pGOLD assay correlate well with FRNT, and quantitative results may inform patient risk stratification.

(1) Background: The influenza virus continues to cause significant annual morbidity and mortality. The overall efficacy of seasonal influenza vaccination is suboptimal, which is partly due to host immune factors. The effects of imprinting and repeated seasonal influenza vaccination were investigated to assess for immune factors and mechanisms that impact influenza vaccine responses. (2) Methods: Twenty participants were enrolled into a prospective pilot study based on birth cohort and seasonal influenza immunization history. Immunologic parameters were assessed over a six-month period after the seasonal influenza vaccine was administered. (3) Results: There was no significant imprinting effect, as measured by hemagglutination inhibition (HAI) fold change, HAI geometric mean titer (GMT) for Day 29 or Day 180 post-vaccination and antigen- specific antibody-secreting cells (ASC) for Day 8 post-vaccination. Individuals who had minimal prior seasonal influenza vaccination had a higher magnitude ASC response and a higher HAI fold change post-vaccination than individuals who were repeatedly vaccinated. (4) Conclusions: Repeated seasonal influenza vaccination resulted in a decreased fold change of the immune response, although individuals in this cohort tended to have high HAI titers at baseline that persisted after vaccination. Imprinting effects were not observed in this cohort. These host immune factors should be considered in the development of universal influenza vaccines. ClinicalTrials.gov Identifier: NCT03686514

Background Recurrent infections are associated with neurodevelopmental (ND) delay in infants, but the primary drivers are poorly understood. Leveraging an infant cohort from rural Guatemala designed to evaluate the effects of post-natal Zika virus on ND (DMID 16-0057), we evaluated the association between cumulative illness and ND delay and stunting. Methods Infants enrolled at 0-3 months of age underwent weekly at-home surveillance for caregiver-reported syndromic illness, including cough, fever and vomiting/diarrhea for a 12-month period. Anthropometric assessments and ND testing by Guatemalan psychologists using the Mullen Scales of Early Learning (MSEL) were perforrmed at 12-15 months of age. Multivariable generalized linear regression models were used to test associations between syndromic illness in infancy, 12-15-month MSEL Early Learning Composite (ELC) Score, and stunting (height-for-age < -2 SD) at 12-15 months. Results The cohort (n=425) had a mean enrollment age of 1.3 months; 202 (48%) were female, 387 (91%) self-reported a literate mother, and 301 (71%) were breastfeeding at study completion. Infants had reported illness for a median of 16 weeks during the surveillance period; cough was reported most frequently (median=11 weeks, range=0-37 weeks). Lower maternal education (p=0.007) and literacy (p=0.002) as well as infant age (p=0.007) and male gender (p=0.004) were associated with MSEL ELC Score Conclusion In a cohort of Guatemalan infants, cumulative fever and cough episodes were significantly associated with lower MSEL ELC Score, whereas there was no association with diarrhea/vomiting. In this low-resource community, these findings highlight the potential negative ND consequences of febrile illness and persistent cough in the first year of life. NIAID Contract HHSN272201300015I Task Order HHSN27200013 (Co-PIs: FMM and EJA). Disclosures Molly Lamb, PhD, BioFire (Grant/Research Support) Evan J. Anderson, MD, Sanofi Pasteur (Scientific Research Study Investigator)

Background Little is known about the epidemiology of Cytomegalovirus (CMV) infection in low resource countries. We evaluated the frequency and effects of post-natal CMV infection in infants from a prospective cohort study designed to assess the effects of post-natal Zika on neurodevelopment (ND) in rural Guatemala. Infants with CMV infection (blue bars) were older compared CMV-negative (red bars) infants. Methods Infants were evaluated for CMV infection by PCR using urine samples collected at 0-3 months of age. ND testing was conducted by local psychologists using a culturally adapted Mullen Scales of Early Learning (MSEL). We explored associations between CMV infection and microcephaly, neurological, visual and hearing deficits, malnutrition and ND outcomes at 1 year of age. Results The infant cohort (N = 469) had a mean age at enrollment of 1.5 (SD 0.75) months; 47% were female and 71% were breastfeeding at 1 year. A total of 103 (22%) were CMV positive and the majority of these (97%) were > 4 weeks of age at testing. Infants > 4 weeks of age were more likely to be CMV positive (P < 0.0001) (Figure). Gender was not correlated with CMV positivity. Among children with head circumference (HC) measurements, microcephaly (HC < 2 SD) was present in 9/87 (10.3%) CMV positive and 35/338 (10.4%) CMV negative infants at 0-3 months of age (p =0.99). Among 438 infants who underwent screening for hearing deficits and a complete ophthalmologic evaluation, none of the CMV positive children had abnormal vision or hearing. Abnormal neurological exams in the first year of life occurred in 50/100 (50%) CMV positive and 166/365 (45.5%) CMV negative infants (p =0.56). There was no association between CMV infection at 0-3 months and MSEL overall or subdomain scores at 1 year (overall Relative risk (RR) 1.02, 95% CI 0.99-1.05, p=0.16). Malnutrition at 0-3 months (RR: 1.53, 95% CI 0.89-2.66, p = 0.13) and 1 year (RR: 1.10, 95% CI 0.77-1.58, p=0.59) was not associated with CMV infection at 0-3 months. Conclusion In a cohort of Guatemalan infants, postnatal CMV infection was common (22%) and more likely to occur after the neonatal period. There was no correlation between CMV infection and microcephaly at 0-3 months or at 1 year of age, nor with abnormal nutritional, neurologic, ophthalmologic, hearing or ND deficits at 1 year of age. This is the first epidemiologic report on CMV infection in early life in rural Guatemala. Disclosures Molly Lamb, PhD, BioFire (Grant/Research Support)

Chikungunya virus (CHIKV) is an alphavirus that is primarily transmitted by Aedes species mosquitoes. Though reports of an illness consistent with chikungunya date back over 200 years, CHIKV only gained worldwide attention during a massive pandemic that began in East Africa in 2004. Chikungunya, the clinical illness caused by CHIKV, is characterized by a rapid onset of high fever and debilitating joint pain, though in practice, etiologic confirmation of CHIKV requires the availability and use of specific laboratory diagnostics. Similar to infections caused by other arboviruses, CHIKV infections are most commonly detected with a combination of molecular and serological methods, though cell culture and antigen detection are reported. This review provides an overview of available CHIKV diagnostics and highlights aspects of basic virology and epidemiology that pertain to viral detection. Although the number of chikungunya cases has decreased since 2014, CHIKV has become endemic in countries across the tropics and will continue to cause sporadic outbreaks in naive individuals. Consistent access to accurate diagnostics is needed to detect individual cases and initiate timely responses to new outbreaks.

Background Clinical, virologic, and immunologic characteristics of Zika virus (ZIKV) infections in US patients are poorly defined. Methods US subjects with suspected ZIKV infection were enrolled. Clinical data and specimens were prospectively collected for ZIKV RNA detection and serologic and cellular assays. Confirmed ZIKV infection (cases) and ZIKV-negative (controls) subjects were compared. Dengue-experienced and dengue-naïve cases were also compared. Results We enrolled 45 cases and 14 controls. Commonly reported symptoms among cases and controls were maculopapular rash (97.8% and 81.8%), fatigue (86.7% and 81.8%), and arthralgia (82.2% and 54.5%), respectively. The sensitivity (94%) and duration of infection detection (80% positivity at 65–79 days after disease onset) by polymerase chain reaction were highest in whole-blood specimens. ZIKV-neutralizing antibodies had a half-life of 105 days and were significantly higher in dengue virus–experienced cases than naïve ones (P = .046). In intracellular cytokine staining assays, the ZIKV proteins targeted most often by peripheral blood mononuclear cells from cases were structural proteins C and E for CD4+ T cells and nonstructural proteins NS3, NS5, and NS4B for CD8+ T cells. Conclusions ZIKV RNA detection was more frequent and prolonged in whole-blood specimens. Immunoglobulin G (IgG) and neutralizing antibodies, but not IgM, were influenced by prior dengue infection. Robust cellular responses to E and nonstructural proteins have potential vaccine development implications.

Background Diagnosing ZIKV infection in children in dengue (DENV) endemic regions is challenging. The kinetics and effects of maternal Ab on infant infection responses remain unknown, as do the ND effects of ZIKV acquired in early life. Methods This is a population-based prospective cohort study in infant–mother pairs and children Results In total, 1,371 subjects (374 children 1–5 years, 500 infants, 497 mothers) were enrolled from June 2017 to July 2018. Among 1,335 evaluable subjects, 7.6% (101) had serologic evidence of recent ZIKV infection (NAb >500 or >100 and DENV-neg); 13.2% (176) were DENV-pos only; 44.8% (598) were ZIKV-neg (NAb15 − Conclusion Serologic evidence of recent ZIKV infection, but no acute ZIKV, was documented in young children in Guatemala. Infant seroreactivity derives from prior maternal infection and DENV cross-reactivity. Observed substantial differences in ND scores between infants and children 1–5 years challenge the ability to isolate the potential effects of ZIKV infection in early life. NIAID Contract HHSN272201300015I Task Order HHSN27200013. FMM and EJA Co-PIs. Disclosures Flor M. Munoz, MD, Biocryst: Grant/Research Support; CDC: Research Grant; Moderna: Other Financial or Material Support, Safety Monitoring Board Member/Chair; NIH: Research Grant; Novavax: Research Grant; UP to Date: Author and Editor: Royalties, Other Financial or Material Support.

Background The impact of early post-natal Zika virus (ZIKV) infection on neurodevelopment (ND) is unknown. A prospective study of post-natal ZIKV infection in rural Guatemala (ZIKV study) enrolled a cohort of children ages 1–5 years, including children previously enrolled in a dengue virus (DENV) study during the 2015–2016 ZIKV epidemic. We evaluated ND outcomes by age and ZIKV infection status. Methods Subjects enrolled in the ZIKV study June 2017–April 2018 underwent ND testing using the Mullen Scales of Early Learning (MSEL) at baseline and 12 months later. ZIKV/DENV-1/2 FRNT50 was performed on enrollment and on banked serum samples from the 2015 to 2016 subset. ZIKV serostatus and MSEL scores were correlated using multiple linear mixed models, adjusted for age and gender when appropriate, to evaluate their association. Geolocation was used to explore clustering of ZIKV serostatus and MSEL score. Results We enrolled 183 children (43% female, mean age 3.2 years). Of these, 38 (21%) were classified as ZIKV-positive (+), 111 (61%) ZIKV-negative (-), 31 (17%) ZIKV-possible, and 3 (2%) ZIKV-indeterminate. ZIKV(+) cases and higher composite MSEL scores clustered in more densely populated areas (Figure 1). ZIKV(+) serostatus was associated with higher MSEL composite (increase in log score 0.09, P = 0.003) and subdomain scores: fine motor (0.13, P = 0.011), visual reception (0.15, P = 0.002), receptive language (0.09, P = 0.041), gross motor (0.14, P = 0.09), and expressive language (0.09, P = 0.058) (Figure 2). Of the 78 children (43%) with 2015–2016 samples, 46 (59%) remained ZIKV(−), 16 (21%) seroconverted from ZIKV(−) or possible/indeterminate to ZIKV(+), and 16 (21%) were indeterminate when enrolled in the ZIKV study. ZIKV seroconversion was associated with higher composite (0.13, P = 0.02) MSEL scores compared with ZIKV(−). Conclusion In this exploratory analysis, post-natal ZIKV infection was not associated with adverse ND outcomes in children age 1–5 years. Overall, ZIKV(+) status was associated with higher average ND scores than ZIKV(−), and scores decreased with age for most children, independent of ZIKV status. The correlation of ZIKV(+) status and higher MSEL scores may be confounded by geographic-related factors or other confounders. NIAID Contract HHSN272201300015I Task Order HHSN27200013 (Co-PIs: FMM & EJA). Disclosures Flor M. Munoz, M.D, Biocryst: Grant/Research Support; CDC: Research Grant; Moderna: Other Financial or Material Support, Safety Monitoring Board Member/Chair; NIH: Research Grant; Novavax: Research Grant; UP to Date: Author and Editor - Royalties, Other Financial or Material Support.

Objective Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Myeloid phagocytes, including blood monocytes recruited to demyelinating lesions, may play a dual role in MS: on one hand, they might enhance CNS damage after differentiating toward a proinflammatory phenotype; on the other, they promote remyelination and repair through effective phagocytosis of myelin debris. We have previously determined that the retinoid X receptor (RXR) plays an important role in monocyte phagocytosis of myelin. Peroxisome proliferator‐activated receptor γ is an RXR binding partner that plays a key role in myeloid cell biology and is targeted by the thiazolidinedione group of antidiabetics such as pioglitazone. Consequently, the purpose of this study was to determine if monocyte functions and differentiation profiles differ in MS patients compared to healthy volunteers (HV) and whether pioglitazone can reverse these differences to promote CNS recovery. Methods Monocytes were isolated from MS patients and HV (n ≥ 36/group), and their ability to phagocytose myelin and modulate inflammation in the presence/absence of 1 μmol/L pioglitazone (the in vivo achievable concentration) was quantified by flow cytometry, transcriptional profiling, and proteomic assays. Results MS monocytes display impaired phagocytosis of myelin debris and enhanced proinflammatory differentiation. Pioglitazone treatment causes partial normalization of identified monocyte abnormalities in MS and fully reverses the deficit in myelin phagocytosis. Interpretation These findings suggest that by inhibiting proinflammatory differentiation of monocytes and enhancing their phagocytosis of myelin, pioglitazone may be a useful adjunct therapy to immunomodulatory agents that target dysregulated adaptive immunity in MS.

Objective The management of complex patients with neuroimmunological diseases is hindered by an inability to reliably measure intrathecal inflammation. Currently implemented laboratory tests developed >40 years ago either are not dynamic or fail to capture low levels of central nervous system (CNS) inflammation. Therefore, we aimed to identify and validate biomarkers of CNS inflammation in 2 blinded, prospectively acquired cohorts of untreated patients with neuroimmunological diseases and embedded controls, with the ultimate goal of developing clinically useful tools. Methods Because biomarkers with maximum utility reflect immune phenotypes, we included an assessment of cell specificity in purified primary immune cells. Biomarkers were quantified by optimized electrochemiluminescent immunoassays. Results Among markers with cell-specific secretion, soluble CD27 is a validated biomarker of intrathecal T-cell activation, with an area under the receiver operating characteristic curve of 0.97. Comparing the quantities of cerebrospinal fluid (CSF) immune cells and their respective cell-specific soluble biomarkers (released by CSF cells as well as their counterparts in CNS tissue) provided invaluable information about stationary CNS immune responses, previously attainable via brain biopsy only. Unexpectedly, progressive and relapsing–remitting multiple sclerosis (MS) patients have comparable numbers of activated intrathecal T and B cells, which are preferentially embedded in CNS tissue in the former group. Interpretation The cell-specific biomarkers of intrathecal inflammation may improve diagnosis and management of neuroimmunological diseases and provide pharmacodynamic markers for future therapeutic developments in patients with intrathecal inflammation that is not captured by imaging, such as in progressive MS. Ann Neurol 2015;78:3–20

Understanding the immune response during acute Zika in humans will aid vaccine design and testing. In 5 acute patients, including 2 pregnant women, viral levels and innate, T-, and B-cell responses against Zika or dengue viruses are described., Background There is an urgent need for studies of viral persistence and immunity during human Zika infections to inform planning and conduct of vaccine clinical trials. Methods In 5 returned US travelers with acute symptomatic Zika infection, clinical features, viral RNA levels, and immune responses were characterized. Results Two pregnant, flavivirus-experienced patients had viral RNA persist in plasma for >44 and >26 days. Three days after symptom onset, transient increases in proinflammatory monocytes began followed at 5 days by transient decreases in myeloid dendritic cells. Anti-Zika virus immunoglobulin M was detected at day 7 after symptom onset, persisted beyond 103 days, and remained equivocal through day 172. Zika virus–specific plasmablasts and neutralizing antibodies developed quickly; dengue virus–specific plasmablasts and neutralizing antibodies at high titers developed only in flavivirus-experienced patients. Zika virus– and dengue virus–specific memory B cells developed in both flavivirus-naive and -experienced patients. CD4+ T cells were moderately activated and produced antiviral cytokines after stimulation with Zika virus C, prM, E, and NS5 peptides in 4/4 patients. In contrast, CD8+ T cells were massively activated, but virus-specific cells that produced cytokines were present in only 2/4 patients assessed. Conclusions Acute infections with Zika virus modulated antigen-presenting cell populations early. Flavivirus-experienced patients quickly recalled cross-reactive MBCs to secrete antibodies. Dengue virus–naive patients made little dengue-specific antibody but developed MBCs that cross-reacted against dengue virus. Zika virus–specific functional CD4+ T cells were readily detected, but few CD8+ T cells specific for the tested peptides were found.

Background The host immune response to influenza vaccination can be affected by prior imprinting to a specific influenza strain based on birth cohort and prior influenza vaccination history. Understanding the underlying immune mechanisms is essential to development of an improved seasonal vaccine and an effective universal influenza vaccine. Methods This is a prospective pilot study, with a total of 20 subjects in either the H3N2 cohort (N = 10, born 1968–1977) or the H1N1 cohort (N = 10, born 1948–1957). Each cohort was further stratified by subjects who have received the influenza vaccine < 2 or ≥ 3 of the past 5 years. The FDA-approved quadrivalent 2018–19 influenza vaccine (containing A(H1N1), an A/Michigan/45/2015-like virus; A(H3N2), an A/Singapore/INFIMH-16–0019/2016-like virus; B/Colorado/06/2017-like virus; and B/Phuket/3073/2013-like virus) was administered on Day 1. Demographic information included age, gender, ethnicity, and BMI. HAI titers for each component of the vaccine were obtained at baseline, 29 days post-vaccination, and 180 days post-vaccination. HAI fold-change and HAI geometric mean titers (GMT) were analyzed. Results There was no significant difference between H1N1 or H3N2 HAI fold-change in the H3N2 birth cohort (P = 0.7496) or in the H1N1 birth cohort (P = 0.8237), Figure A. Comparing HAI fold-change for the repeatedly vs. minimally vaccinated groups, there was a significant higher fold change in the minimally vaccinated group (H1N1 HAI (P = 0.002) and H3N2 HAI (P < 0.0001), Figure B). GMT was higher at baseline for the repeatedly vaccinated group (H1N1, 70; H3N2, 98; vs. H1N1, 30; H3N2, 21 for the minimally vaccinated group); however, the GMT for the minimally vaccinated group was higher at day 29 (H1N1, 172; H3N2, 184; vs. H1N1, 422; H3N2, 299 for the minimally vaccinated group; Figure C). HAI titers and analysis at day 180 post vaccination are in progress. Conclusion There was no evidence of an imprinting effect by birth cohort for HAI titer magnitudes, even when stratified by vaccination history. There was a significantly higher HAI fold change for individuals who had received minimal influenza vaccinations in the past 5 years at 29 days post-vaccination. Individuals who had repeated vaccinations in the last 5 years had higher HAI GMT at baseline. Disclosures Nadine Rouphael, MD, Merck: I conduct as Emory PI the PNEUMO MERCK study at Emory, Research Grant; Pfizer: I conduct as co-PI the RSV PFIZER study at Emory, Research Grant; Sanofi-Pasteur: I conducted as Emory PI the CDIFFENSE trial at Emory, Research Grant.

Despite the widespread outbreak, few cases of Zika virus associated with cardiac manifestations have been described. We present a case of pericarditis in the setting of an acute, symptomatic Zika virus infection in a traveler returning from St. Thomas. Clinicians should be alert for this potential complication of Zika virus infection.

During the current Zika virus (ZIKV) outbreak, acute symptomatic ZIKV infection in adults appears to be a mild-to-moderate, self-limited illness. We present a case of ZIKV rash illness that improved and then relapsed without repeat exposure to ZIKV. Clinicians should be alert for relapses in patients with ZIKV infection.

Background The clinical, virologic and immunologic characteristics of Zika virus (ZIKV) infections in US patients are poorly defined. Methods US patients with suspected Zika virus (ZIKV) infection were enrolled and clinical data and specimens were prospectively collected. Body fluids were tested for ZIKV RNA by PCR and blood was tested using serologic and cellular immune assays. Findings from those with confirmed ZIKV infections (cases) and ZIKV-negative controls were compared. Results We enrolled 45 cases and 14 controls. The most commonly reported symptoms among cases and controls were maculopapular rash (97.8% and 81.8%), fatigue (86.7% and 81.8%) and arthralgia (82.2% and 54.5%), respectively. The sensitivity and duration of detection by PCR were highest in whole blood samples (94% of 35 cases who had samples collected up to day 79 post illness onset were positive); strikingly, 84% of those were still positive at 65–79 days post illness onset (Figure 1). ZIKV neutralizing antibodies were detected in all cases and none of the controls, and titers were significantly higher in dengue virus (DENV)-experienced subjects than in DENV-naïve ones (Figure 2). Among cases, anti-ZIKV IgG antibodies were also significantly higher in DENV-experienced patients, while anti-ZIKV IgM antibodies were no higher in DENV-experienced compared with naïve ones. Using intracellular cytokine staining, the highest frequencies of T cells producing IFN-γ, IL-2 and/or TNF-α were against the NS1, NS3, and NS5 proteins for CD4+ T cells, and against the E, NS3, and NS5 proteins for CD8+ T cells (Figure 3). Conclusion Detection of ZIKV RNA was more frequent and much more prolonged in whole blood samples compared with other body fluids. Diagnostic molecular assays on this easily obtained fluid should be prioritized for point-of-care development. Robust cellular responses to E, NS3 and NS5 proteins could have implications for vaccine development. Disclosures R. L. Atmar, Takeda Vaccines, Inc.: Investigator, Research grant.