IMPORTANCE Control of the global COVID-19 pandemic will require the development and deployment of safe and effective vaccines. OBJECTIVE To evaluate the immunogenicity of the Ad26.COV2.S vaccine (Janssen/Johnson & Johnson) in humans, including the kinetics, magnitude, and phenotype of SARS-CoV-2 spike-specific humoral and cellular immune responses. DESIGN, SETTING, AND PARTICIPANTS Twenty-five participants were enrolled from July 29, 2020, to August 7, 2020, and the follow-up for this day 71 interim analysis was completed on October 3, 2020; follow-up to assess durability will continue for 2 years. This study was conducted at a single clinical site in Boston, Massachusetts, as part of a randomized, double-blind, placebo-controlled phase 1 clinical trial of Ad26.COV2.S. INTERVENTIONS Participants were randomized to receive 1 or 2 intramuscular injections with 5 × 10 10 viral particles or 1 × 10 11 viral particles of Ad26.COV2.S vaccine or placebo administered on day 1 and day 57 (5 participants in each group). MAIN OUTCOMES AND MEASURES Humoral immune responses included binding and neutralizing antibody responses at multiple time points following immunization. Cellular immune responses included immunospot-based and intracellular cytokine staining assays to measure T-cell responses. RESULTS Twenty-five participants were randomized (median age, 42; age range, 22-52; 52% women, 44% male, 4% undifferentiated), and all completed the trial through the day 71 interim end point. Binding and neutralizing antibodies emerged rapidly by day 8 after initial immunization in 90% and 25% of vaccine recipients, respectively. By day 57, binding and neutralizing antibodies were detected in 100% of vaccine recipients after a single immunization. On day 71, the geometric mean titers of spike-specific binding antibodies were 2432 to 5729 and the geometric mean titers of neutralizing antibodies were 242 to 449 in the vaccinated groups. A variety of antibody subclasses, Fc receptor binding properties, and antiviral functions were induced. CD4+ and CD8+ T-cell responses were induced. CONCLUSION AND RELEVANCE In this phase 1 study, a single immunization with Ad26.COV2.S induced rapid binding and neutralization antibody responses as well as cellular immune responses. Two phase 3 clinical trials are currently underway to determine the efficacy of the Ad26.COV2.S vaccine.

Pleiotropy, in which one mutation causes multiple phenotypes, has traditionally been seen as a deviation from the conventional observation in which one gene affects one phenotype. Epistasis, or gene-gene interaction, has also been treated as an exception to the Mendelian one gene-one phenotype paradigm. This simplified perspective belies the pervasive complexity of biology and hinders progress toward a deeper understanding of biological systems. We assert that epistasis and pleiotropy are not isolated occurrences, but ubiquitous and inherent properties of biomolecular networks. These phenomena should not be treated as exceptions, but rather as fundamental components of genetic analyses. A systems level understanding of epistasis and pleiotropy is, therefore, critical to furthering our understanding of human genetics and its contribution to common human disease. Finally, graph theory offers an intuitive and powerful set of tools with which to study the network bases of these important genetic phenomena.

Hippocampal theta rhythm is believed to play a critical role in learning and memory. In animal models of temporal lobe epilepsy (TLE), there is evidence that alterations of hippocampal theta oscillations are involved in the cognitive impairments observed in this model. However, hippocampal theta frequency and amplitude at both the local field potential (LFP) and single unit level are strongly modulated by running speed, suggesting that the integration of locomotor information into memory processes may also be critical for hippocampal processing. Here, we investigate whether hippocampal speed-theta integration influences spatial memory and whether it could account for the memory deficits observed in TLE rats. LFPs were recorded in both Control (CTR) and TLE rats as they were trained in a spatial alternation task. TLE rats required more training sessions to perform the task at CTR levels. Both theta frequency and power were significantly lower in the TLE group. In addition, speed/theta frequency correlation coefficients and regression slopes varied from session to session and were worse in TLE. Importantly, there was a strong relationship between speed/theta frequency parameters and performance. Our analyses reveal that speed/theta frequency correlation with performance cannot merely be explained by the direct influence of speed on behavior. Therefore, variations in the coordination of theta frequency with speed may participate in learning and memory processes. Impairments of this function could explain at least partially memory deficits in epilepsy.

Objective The two objectives of this study were (1) to replicate the previous finding that a single nucleotide polymorphism (SNP) in the ANKK1 gene (SNP rs1800497 formerly known as the DRD2 TAQ1 A allele) is associated with measures of learning and response latency after traumatic brain injury (TBI), and (2) to further characterize the genetic basis of the effect by testing the strength of association and degree of linkage disequilibrium between the cognitive outcome measures and a selected ensemble of 31 polymorphisms from three adjacent genes in the region of rs 1800497. Method A cohort of 54 patients with TBI and 21 comparison subjects were genotyped for the DRD2 TAQ1 A polymorphism (rs1800497). Ninety-three patients with TBI and 48 comparison subjects (the current cohort and an earlier independent cohort) were also genotyped for 31 additional neighboring polymorphisms in NCAM, ANKK1, and DRD2. TBI patients were studied one month after injury. All subjects completed memory and attention tests, including the California Verbal Learning Test (CVLT) recognition task and the Gordon Continuous Performance Test (CPT). Results As in our previous study the T allele of TAQ1 A (rs 1800497) was associated with poorer performance on the CVLT recognition trial in both TBI and control subjects. There was also a significant diagnosis-by-allele interaction on CPT measures of response latency largely driven by slower performance in the TBI participants with the T allele. Analysis of 31 additional neighboring polymorphisms from NCAM, ANKK1, and DRD2 in the TBI patients showed four haploblocks. A haploblock of 3 SNPs in ANKK1 (rs11604671, rs4938016, and rs1800497 [TAQ1A]) showed the greatest association with cognitive outcome measures. Conclusions Our results confirm our previously published association between the TAQ1 A (rs1800497) T allele and cognitive outcome measures one month after TBI, and suggest that a haploblock of polymorphisms in ANKK1, rather than the adjacent DRD2 gene, has the highest association with these measures after TBI.

Brain-derived neurotrophic factor (BDNF) plays a role in cognition, as well as neural survival and plasticity. There are several common polymorphisms in the BDNF gene, one of which (rs6265) is an extensively studied non-synonymous coding polymorphism (Val66Met) which has been linked to cognitive performance in healthy controls and some clinical populations. We hypothesized that the Met allele of rs6265 would be associated with poorer cognitive performance in individuals with mild-to-moderate traumatic brain injury, and that other polymorphisms in the BDNF gene would also affect cognition. Genotype at 9 single-nucleotide polymorphisms (SNPs) in the BDNF gene, and measures of speed of information processing, learning, and memory were assessed in 75 patients with mTBI and 38 healthy subjects. Consistent with previous reports, the Met allele of rs6265 was associated with cognition (slower processing speed) in the entire group. Two other SNPs were associated with processing speed in the mTBI group, but both are in linkage disequilibrium with rs6265, and neither remained significant after adjustment for rs6265 status. Within the mTBI group, but not the controls, 4 SNPs, but not rs6265, were associated with memory measures. These associations were not affected by adjustment for rs6265 status. Polymorphisms in BDNF influence cognitive performance shortly after mTBI. The results raise the possibility that a functional polymorphism other than rs6265 may contribute to memory function after mTBI.