The infected and the affected: A longitudinal study of the impact of the COVID-19 pandemic on schoolchildren in Florida.

Objectives: To identify risk factors associated with symptoms of anxiety, depression, and obsessive-compulsive disorder (OCD) among children during the 1st year of the COVID-19 pandemic. Methods: A longitudinal study with three cross-sectional timepoints [April 2020 (n = 273), October 2020 (n = 180), and April 2021 (n = 116)] was conducted at a K-12 public school in Florida. Infection and sero-positivity for SARS-CoV-2 was determined by molecular and serologic approaches. Adjusted odds ratios using mixed effect logistic regression models for symptom-derived indicators of anxiety, depression, and OCD in children in April 2021 are presented; past infection and seropositivity were included in the models. Results: The prevalence of anxiety, depression, or OCD moved from 47.1, to 57.2, to 42.2% across the three timepoints during the study. By endline of the study, in April 2021, non-white children were at higher risk for depression and OCD. Risk for anxiety, depression, and OCD was associated with students who lost a family member due to COVID-19 and who were identified as at-risk in previous timepoints. Rates of SARS-CoV-2 infection and seropositivity were low and not statistically associated with assessed outcomes. Conclusions: In situations like the COVID-19 pandemic, targeted mental health interventions and screenings are needed in children and adolescents, especially among minority children.

Everglades virus evolution: Genome sequence analysis of the envelope 1 protein reveals recent mutation and divergence in South Florida wetlands.

Everglades virus (EVEV) is a subtype (II) of Venezuelan equine encephalitis virus (VEEV), endemic in southern Florida, USA. EVEV has caused clinical encephalitis in humans, and antibodies have been found in a variety of wild and domesticated mammals. Over 29,000 Culex cedecei females, the main vector of EVEV, were collected in 2017 from Big Cypress and Fakahatchee Strand Preserves in Florida and pool-screened for the presence of EVEV using reverse transcription real-time polymerase chain reaction. The entire 1 E1 protein gene was successfully sequenced from fifteen positive pools. Phylogenetic analysis showed that isolates clustered, based on the location of sampling, into two monophyletic clades that diverged in 2009. Structural analyses revealed two mutations of interest, A116V and H441R, which were shared among all isolates obtained after its first isolation of EVEV in 1963, possibly reflecting adaptation to a new host. Alterations of the Everglades ecosystem may have contributed to the evolution of EVEV and its geographic compartmentalization. This is the first report that shows in detail the evolution of EVEV in South Florida. This zoonotic pathogen warrants inclusion into routine surveillance given the high natural infection rate in the vectors. Invasive species, increasing urbanization, the Everglades restoration, and modifications to the ecosystem due to climate change and habitat fragmentation in South Florida may increase rates of EVEV spillover to the human population.

SARS-CoV-2 infections in infants in Haiti 2020-2021; evidence from a seroepidemiological cohort.

Few data are available on frequency of SARS-CoV-2 infection among very young children in low- to middle-income countries (LMIC), with the studies that are available biased towards higher income countries with low reported infection and seroconversion rates. Between February 2019 and March 2021, 388 dried blood spot (DBS) samples were obtained from 257 children less than 30 months of age as part of a prospective observational cohort study of pregnant women and their infants in Haiti; longitudinal samples were available for 107 children. In a subsequent retrospective analysis, DBS samples were tested by ELISA for antibody targeting the receptor binding domain of the SARS-CoV-2 S1 protein. Over the course of the study, 16·7% of the infants became seropositive. All seropositive samples were collected after March 19, 2020 (the date of the first reported COVID-19 case in Haiti) with the highest hazards measured in August 2020. Sampling date was the only covariate associated with the hazard of seroconversion. Our data provide an estimate of SARS-CoV-2 infection rates among very young children without prior SARS-CoV-2 exposure during the initial pandemic waves in Haiti, and demonstrate that these children mount a detectable serological response which is independent of patient age.

Strain-Dependent Activity of Zika Virus and Exposure History in Serological Diagnostics.

Zika virus (ZIKV) circulates as two separate lineages, with significant genetic variability between strains. Strain-dependent activity has been reported for dengue virus, herpes simplex virus and influenza. Strain-dependent activity of subject specimens to a virus could be an impediment to serological diagnosis and vaccine development. In order to determine whether ZIKV exhibits strain-dependent activity when exposed to antibodies, we measured the neutralizing properties of polyclonal serum and three monoclonal antibodies (ZKA185, 753(3)C10, and 4G2) against three strains of ZIKV (MR-766, PRVABC59, and R103454). Here, MR-766 was inhibited almost 60% less by ZKA185 than PRVABC59 and R103454 (p = 0.008). ZKA185 enhanced dengue 4 infection up to 50% (p = 0.0058). PRVABC59 was not inhibited by mAb 753(3)C10 while MR-766 and R103453 were inhibited up to 90% (p = 0.04 and 0.036, respectively). Patient serum, regardless of exposure history, neutralized MR-766 ~30%-40% better than PRVABC56 or R103454 (p = 0.005-0.00007). The most troubling finding was the significant neutralization of MR-766 by patients with no ZIKV exposure. We also evaluated ZIKV antibody cross reactivity with various flaviviruses and found that more patients developed cross-reactive antibodies to Japanese encephalitis virus than the dengue viruses. The data here show that serological diagnosis of ZIKV is complicated and that qualitative neutralization assays cannot discriminate between flaviviruses.

Experimental Infection of Mid-Gestation Pregnant Female and Intact Male Sheep with Zika Virus.

Zika virus (ZIKV) is an arbovirus that causes birth defects, persistent male infection, and sexual transmission in humans. The purpose of this study was to continue the development of an ovine ZIKV infection model; thus, two experiments were undertaken. In the first experiment, we built on previous pregnant sheep experiments by developing a mid-gestation model of ZIKV infection. Four pregnant sheep were challenged with ZIKV at 57-64 days gestation; two animals served as controls. After 13-15 days (corresponding with 70-79 days of gestation), one control and two infected animals were euthanized; the remaining animals were euthanized at 20-22 days post-infection (corresponding with 77-86 days of gestation). In the second experiment, six sexually mature, intact, male sheep were challenged with ZIKV and two animals served as controls. Infected animals were serially euthanized on days 2-6 and day 9 post-infection with the goal of isolating ZIKV from the male reproductive tract. In the mid-gestation study, virus was detected in maternal placenta and spleen, and in fetal organs, including the brains, spleens/liver, and umbilicus of infected fetuses. Fetuses from infected animals had visibly misshapen heads and morphometrics revealed significantly smaller head sizes in infected fetuses when compared to controls. Placental pathology was evident in infected dams. In the male experiment, ZIKV was detected in the spleen, liver, testes/epididymides, and accessory sex glands of infected animals. Results from both experiments indicate that mid-gestation ewes can be infected with ZIKV with subsequent disruption of fetal development and that intact male sheep are susceptible to ZIKV infection and viral dissemination and replication occurs in highly vascular tissues (including those of the male reproductive tract).

Experimental Infection of Pregnant Female Sheep with Zika Virus During Early Gestation.

Zika virus (ZIKV) is a vertically and sexually transmissible virus resulting in severe congenital malformation. The goal of this study was to develop an ovine model of ZIKV infection. Between 28-35 days gestation (DG), four pregnant animals were infected with two doses of 6 × 106 PFU of ZIKV; four control animals received PBS. Animals were evaluated for 45 days (D) post-infection (PI) and necropsies were performed. Viral RNA was detected in infected ewe peripheral blood mononuclear cells (PBMC) during the first week PI; however, all fluids and tissues were negative upon culture. Anti-ZIKV IgM (1:400) and neutralizing antibodies were detected in all infected animals. Clinical disease, virus, or ZIKV antibodies were not detected in control ewes. After two weeks PI, fetal loss occurred in two infected animals, and at necropsy, three infected animals had placental petechiation and ecchymosis and one had hydramnion. Fetal morphometrics revealed smaller cranial circumference to crown-rump length ratios (p < 0.001) and relative brain weights (p = 0.038) in fetuses of infected animals compared with control fetuses. Immunophenotyping indicated an increase in B cells (p = 0.012) in infected sheep. Additionally, in vitro experiments using both adult and fetal cell lines demonstrated that ovine cells are highly permissive to ZIKV infection. In conclusion, ZIKV infection of pregnant sheep results in a change in fetal growth and gestational outcomes.

An initial examination of the potential role of T-cell immunity in protection against feline immunodeficiency virus (FIV) infection.

The importance of vaccine-induced T-cell immunity in conferring protection with prototype and commercial FIV vaccines is still unclear. Current studies performed adoptive transfer of T cells from prototype FIV-vaccinated cats to partial-to-complete feline leukocyte antigen (FLA)-matched cats a day before either homologous FIVPet or heterologous-subtype pathogenic FIVFC1 challenge. Adoptive-transfer (A-T) conferred a protection rate of 87% (13 of 15, p < 0.001) against FIVPet using the FLA-matched T cells, whereas all 12 control cats were unprotected. Furthermore, A-T conferred protection rate of 50% (6 of 12, p<0.023) against FIVFC1 using FLA-matched T cells, whereas all 8 control cats were unprotected. Transfer of FLA-matched T and B cells demonstrated that T cells are needed to confer A-T protection. In addition, complete FLA-matching and addition of T-cell numbers > 13 × 10(6) cells were required for A-T protection against FIVFC1 strain, reported to be a highly pathogenic virus resistant to vaccine-induced neutralizing-antibodies. The addition of FLA-matched B cells alone was not protective. The poor quality of the anti-FIV T-cell immunity induced by the vaccine likely contributed to the lack of protection in an FLA-matched recipient against FIVFC1. The quality of the immune response was determined by the presence of high mRNA levels of cytolysin (perforin) and cytotoxins (granzymes A, B, and H) and T helper-1 cytokines (interferon-γ [IFNγ] and IL2). Increased cytokine, cytolysin and cytotoxin production was detected in the donors which conferred protection in A-T studies. In addition, the CD4(+) and CD8(+) T-cell proliferation and/or IFNγ responses to FIV p24 and reverse transcriptase increased with each year in cats receiving 1X-3X vaccine boosts over 4 years. These studies demonstrate that anti-FIV T-cell immunity induced by vaccination with a dual-subtype FIV vaccine is essential for prophylactic protection against AIDS lentiviruses such as FIV and potentially HIV-1.

Feline immunodeficiency virus (FIV) vaccine efficacy and FIV neutralizing antibodies.

A HIV-1 tier system has been developed to categorize the various subtype viruses based on their sensitivity to vaccine-induced neutralizing antibodies (NAbs): tier 1 with greatest sensitivity, tier 2 being moderately sensitive, and tier 3 being the least sensitive to NAbs (Mascola et al., J Virol 2005; 79:10103-7). Here, we define an FIV tier system using two related FIV dual-subtype (A+D) vaccines: the commercially available inactivated infected-cell vaccine (Fel-O-Vax(®) FIV) and its prototype vaccine solely composed of inactivated whole viruses. Both vaccines afforded combined protection rates of 100% against subtype-A tier-1 FIVPet, 89% against subtype-B tier-3 FIVFC1, 61% against recombinant subtype-A/B tier-2 FIVBang, 62% against recombinant subtype-F'/C tier-3 FIVNZ1, and 40% against subtype-A tier-2 FIVUK8 in short-duration (37-41 weeks) studies. In long-duration (76-80 weeks) studies, the commercial vaccine afforded a combined protection rate of at least 46% against the tier-2 and tier-3 viruses. Notably, protection rates observed here are far better than recently reported HIV-1 vaccine trials (Sanou et al., The Open AIDS J 2012; 6:246-60). Prototype vaccine protection against two tier-3 and one tier-2 viruses was more effective than commercial vaccine. Such protection did not correlate with the presence of vaccine-induced NAbs to challenge viruses. This is the first large-scale (228 laboratory cats) study characterizing short- and long-duration efficacies of dual-subtype FIV vaccines against heterologous subtype and recombinant viruses, as well as FIV tiers based on in vitro NAb analysis and in vivo passive-transfer studies. These studies demonstrate that not all vaccine protection is mediated by vaccine-induced NAbs.

Utilization of feline ELISPOT for mapping vaccine epitopes.

A commercial feline immunodeficiency virus (FIV) vaccine consisting of inactivated dual-subtype viruses was released in the USA in 2002 and released subsequently over the next 6 years in Canada, Australia, New Zealand, and Japan. Based on the genetic, morphologic, and biochemical similarities between FIV and human immunodeficiency virus-1 (HIV-1), FIV infection of domestic cats is being used as a small animal model of HIV/AIDS vaccine. Studies on prototype and commercial FIV vaccines provide new insights to the types of immunity and the vaccine epitopes required for an effective human HIV-1 vaccine. ELISPOT assays to detect cytokines, chemokines, and cytolytic mediators are widely used to measure the magnitude and the types of cellular immunity produced by vaccination. Moreover, such approach has identified regions on both HIV-1 and FIV proteins that induce robust antiviral cellular immunity in infected hosts. Using the same strategy, cats immunized with prototype and commercial FIV vaccines are being analyzed by feline interferon-γ and IL-2 ELISPOT systems to identify the vaccine epitope repertoire for prophylaxis.

HIV-1 p24 vaccine protects cats against feline immunodeficiency virus infection.

BACKGROUND: Based on previous analysis of feline immunodeficiency virus (FIV)-specific cross-reactive antibodies to HIV-1 p24, cats vaccinated with HIV-1 p24 were evaluated for cross-reactive immunity to FIV. OBJECTIVE: : To determine the level of cross-reactivity that exists between HIV-1 and FIV p24 and its implications for vaccine prophylaxis. METHODS: Specific-pathogen-free cats were immunized three times with HIV-1 p24 in Ribi adjuvant, with (n = 18) or without cytokine (n = 6). Control cats were immunized three times with adjuvant (n = 10) or phosphate-buffered saline (PBS; n = 5). All immunized cats were challenged with either subtypes B or A/B FIV, and monitored by virus isolation, proviral PCR, FIV-specific antibodies, and feline interferon-gamma ELISpot for T-cell activities. RESULTS: Of 18 cats vaccinated with subtype B HIV-1 (HIV-1LAI/LAV, HIV-1UCD1) p24 in Ribi/cytokine adjuvant 14 (78%) were protected against FIV challenges (subtype Agag and Bgag) that infected all 15 adjuvant- or PBS-immunized cats. Furthermore, only three of six (50%) cats vaccinated with FIV p24 in Ribi/cytokine adjuvant were protected against similar FIV challenge. HIV-1 p24 vaccination induced weak cross-reactive antibodies to FIV p24, which did not correlate with vaccine efficacy. However, the peripheral blood mononuclear cells from HIV-1 p24-vaccinated/protected cats at 33-34 weeks post-FIV challenge responded to three T-cell responsive peptides at the carboxyl-terminus of the FIV p24, whereas those cells from the infected control cats had minimal to no responses to the same peptides. CONCLUSIONS: These results suggest the importance of including lentiviral p24 as vaccine immunogen for human AIDS vaccine. Moreover, these results suggest the potential importance of evolutionarily conserved, cross-protective epitopes in vaccine protection.

Dual-subtype FIV vaccine (Fel-O-Vax FIV) protection against a heterologous subtype B FIV isolate.

Vaccine trials were undertaken to determine whether the Fel-O-Vax FIV, a commercial dual-subtype (subtypes A and D) feline immunodeficiency virus (FIV) vaccine, is effective against a subtype B FIV isolate. Current results demonstrate the Fel-O-Vax FIV to be effective against a subtype B virus, a subtype reported to be the most common in the USA.