A Gamma-adapted subunit vaccine induces broadly neutralizing antibodies against SARS-CoV-2 variants and protects mice from infection

In the context of continuous emergence of SARS-CoV-2 variants of concern (VOCs), one strategy to prevent the severe outcomes of COVID-19 is developing safe and effective broad-spectrum vaccines. Here, we present preclinical studies of a RBD vaccine derived from the Gamma SARS-CoV-2 variant adjuvanted with Alum. The Gamma-adapted RBD vaccine is more immunogenic than the Ancestral RBD vaccine in terms of inducing broader neutralizing antibodies. The Gamma RBD presents more immunogenic B-cell restricted epitopes and induces a higher proportion of specific-B cells and plasmablasts than the Ancestral RBD version. The Gamma-adapted vaccine induces antigen specific T cell immune responses and confers protection against Ancestral and Omicron BA.5 SARS-CoV-2 challenge in mice. Moreover, the Gamma RBD vaccine induces higher and broader neutralizing antibody activity than homologous booster vaccination in mice previously primed with different SARS-CoV-2 vaccine platforms. Our study indicates that the adjuvanted Gamma RBD vaccine is highly immunogenic and a broad-spectrum vaccine candidate.

Anti-parasitic effect of vitamin C alone and in combination with benznidazole against Trypanosoma cruzi

BACKGROUND

Drugs currently used for the treatment of Chagas' disease, nifurtimox and benznidazole, have a limited effectiveness and toxic side effects. With the aim of finding new therapeutic approaches, in vitro and in vivo anti-Trypanosoma cruzi activity of vitamin C alone and combined with benznidazole were investigated.

METHODOLOGY/PRINCIPAL FINDINGS

The trypanocidal activity on epimastigote and trypomastigote forms was evaluated by counting parasites in a Neubauer chamber after treatment with the compounds. For the amastigote stage, transgenic parasites expressing β-galactosidase were used and quantified by measuring the β-galactosidase activity. The cytotoxicity of compounds was tested on Vero cells. The redox state of the parasite was evaluated by determining the reduced thiol levels (spectrophotometric assay) and the intracellular oxidative state (by flow cytometry). The in vivo trypanocidal activity was evaluated on a murine model of Chagas' disease. The trypanocidal activity of vitamin C and benznidazole was similar for the three parasite forms. When combining both drugs, vitamin C did not induce any change in the antiparasitic activity of benznidazole on trypomastigotes; however, on mammal cells, vitamin C diminished the cytotoxicity degree of benznidazole. Two mechanisms of action may be postulated for vitamin C: a lethal pro-oxidant effect on the parasite when used alone, and an antioxidant effect, when combined with benznidazole. A similar behavior was observed on infected mice; i.e., parasite counts in infected mice treated with vitamin C were lower than that of the control group. Animals treated with benznidazole presented lower parasitemia levels, as compared with those treated with vitamin C alone. Again, vitamin C did not cause any effect on the antiparasitic profile of benznidazole. Even though a combined treatment was employed, the antioxidant effect of vitamin C on the host was evidenced; a 100% survival was observed and the weight loss occurring during the acute phase of the infection was reduced.

CONCLUSIONS/SIGNIFICANCE

Based on these results, the combination of vitamin C with benznidazole could be considered as an alternative treatment for Chagas' disease. These preliminary results encourage further research to improve the treatment of Chagas' disease.

Connecting health departments and providers: syndromic surveillance's last mile

INTRODUCTION

A critical need exists for mechanisms to identify and report acute illness clusters to health departments. The Massachusetts Department of Public Health (MDPH) works with partner organizations to conduct syndromic surveillance. This effort is based on CDC's Health Alert Network program and includes automated generation and notification of signals and a mechanism to obtain detailed clinical information when needed.

METHODS

Syndromic surveillance partners collect emergency department and ambulatory care data. The principal communications platform between syndromic surveillance partners and MDPH is the Massachusetts Homeland and Health Alert Network (HHAN). This Internet-based application serves as a portal for communication and collaboration and alerts predefined groups of users involved in emergency response. Syndromic surveillance partners' systems report to HHAN by using Public Health Information Network Messaging System events that meet thresholds selected by MDPH. Cluster summaries are automatically posted into a document library. HHAN notifies users by electronic mail, alphanumeric pager, facsimile, or voice communications; users decide how they want to be notified for each level of alert. Discussion threads permit real-time communication among all parties.

RESULTS

This automated alert system became operational in July 2004. During July-December 2004, HHAN facilitated communication and streamlined investigation of 15 alerts.

CONCLUSION

The system allows rapid, efficient alerting and bidirectional communication among public health and private-sector partners and might be applicable to other public health agencies.

Estimating the sensitivity and specificity of matching name-based with non-name-based case registries

Because non-name-based case registries have recently been used for reporting human immunodeficiency virus infection, this study attempted to define the sensitivity, specificity and accuracy of case registry matches using non-name-based registries. The AIDS, sexually transmitted disease (STD), and tuberculosis (TB) case registries were matched using all available information to establish the standard. The registries were then matched again using five increasingly less specific criteria to compare sensitivity, specificity and accuracy. The registries were then also transformed into non-name-based codes as if they were the HIV registry and matched again. With name-based registries, sensitivities increased as the matching criteria became less exacting, while the accuracy declined slightly. Specificities remained close to 100% due to the relatively small number of matched cases. Results from matches of non-name-based registry matches were similar to those of the name-based registry matches. Non-name reporting can be used for data matching with acceptable accuracy.

Epidemiology of congenital toxoplasmosis identified by population-based newborn screening in Massachusetts

BACKGROUND

Fourteen years of newborn screening in Massachusetts for congenital toxoplasmosis infection identified subpopulations that appeared to have higher rates of infection. Elaborating an epidemiologic profile and risk correlates might aid implementing targeted prenatal education and newborn screening strategies with the goal of early postnatal treatment to prevent morbidity.

OBJECTIVE

To describe the epidemiology of congenital toxoplasmosis in Massachusetts and risk correlates of infection using birth certificate data.

METHODS

A case-control study was conducted based on Massachusetts birth certificate data. Cases were all infants with congenital toxoplasmosis identified by statewide universal newborn screening from 1988 to 1999. Controls were all children born on the same day as those infants in Massachusetts.

RESULTS

Factors that strongly predicted congenital toxoplasmosis infection were mother's country of birth outside the US (especially the southeast Asian refugee origin countries of Cambodia and Laos), mother's educational level and higher gravidity.

CONCLUSIONS

More extensive, culturally and linguistically appropriate, prenatal education is needed for pregnant women, regardless of a mother's educational level, especially for non-US-born mothers, and not focused only on primiparous women. Other states may be able to use their state-specific birth certificate data to compare risk profiles with those of Massachusetts to guide a toxoplasmosis screening policy on the basis of population similarities and differences.

Adherence to medication regimens among children with human immunodeficiency virus infection

BACKGROUND

Rigorous adherence to antiretroviral medication regimens is necessary to achieve and maintain undetectable viral levels. This study describes adherence in a population of children with HIV infection.

METHODS

Caregivers of HIV-infected children were interviewed about their experiences with administration of medications for treatment of HIV, opinions regarding medication-related issues and the potential usefulness of interventions to improve adherence.

RESULTS

In the 90 caregiver interviews completed, 78% of the children were taking 3 or more medications, 17% missed a dose in the previous 24 h and 43% missed at least 1 dose in the previous week. Children whose caregivers reported no missed doses in the previous week (adherent) were more likely to have an HIV viral load <400 copies/ml (50% vs. 24%, P = 0.04). Nonadherent caregivers (who reported 1 or more missed doses in the previous week) were more likely than adherent caregivers to agree with a statement that full adherence is impossible (44% vs. 12%, P = 0.001) and express the need for more help with medication administration (26% vs. 6%, P = 0.02). They were less likely to have informed the school or day-care site about the child's HIV infection (42% vs. 67%, P = 0.05) and more concerned about the child's teachers and friends finding out (54% vs. 31%, P = 0.05). Of 10 potential interventions 6 were rated by a majority of respondents as "very helpful": better tasting medications (81%); longer dosing intervals (72%); medications that did not require refrigeration (63%); access to 24-h telephone advice (62%); a follow-up call from a health care provider (57%); and a pill organizer (56%).

CONCLUSIONS

Caregivers' perceptions that adherence is too difficult or concerns about loss of privacy may affect their ability to adhere to complicated medication regimens. Caregivers felt that the most helpful interventions would be modifications to improve the convenience and palatability of medications and increased access to medical advice.

Normal values of regional left ventricular endocardial motion: multicenter color kinesis study

Our goal was to establish normal values for quantitative color kinesis indexes of left ventricular (LV) wall motion over a wide range of ages, which are required for objective diagnosis of regional systolic and diastolic dysfunction. Color-encoded images were obtained in 194 normal subjects (95 males, 99 females, age 2 mo to 79 yr) in four standard views. Quantitative indexes of magnitude and timing of systolic and diastolic function were studied for age- and gender-related differences. Normal limits of all ejection and filling indexes were in a narrow range (< or =25% of the mean), with no major gender-related differences. Despite invariable ejection fractions, both peak filling and ejection rates decreased with age (30 and 20%, correspondingly) with a concomitant increase in mean filling and ejection times, resulting in five- and twofold increases in the late to early filling and ejection ratios, correspondingly. Diastolic asynchrony increased with age (from 4.7 +/- 2.0 to 6.4 +/- 3.2 from the 2nd to 7th decade). The normal values of color kinesis indexes should allow objective detection of regional LV systolic and diastolic dysfunction.

Perinatally acquired human immunodeficiency virus infection: extent of clinical recognition in a population-based cohort. Massachusetts Pediatric HIV Surveillance Working Group

To evaluate factors that may affect the timely diagnosis of children with human immunodeficiency virus (HIV) infection, we compared data derived from two population-based pediatric HIV studies. Data from anonymous newborn HIV serosurveys were used to estimate the number of children born to HIV-seropositive mothers. A statewide active surveillance project determined the number of HIV-exposed children who had been clinically recognized. Of 88,732 Massachusetts newborn specimens tested anonymously for HIV antibodies during a 12-month period (November, 1987, to October, 1988), 223 were positive. As of October, 1991, 78 of these children (35%) had been identified by a statewide network of infectious disease physicians. HIV-exposed children born in inner city hospitals were more likely to have come to medical attention than those born in suburban hospitals (47% vs. 17%). Among the 29 children with confirmed HIV infection (13% of 223), the initial evaluation for HIV occurred at an earlier age among children born in inner city hospitals than among children born in other areas. HIV testing practices that rely heavily on risk assessment may result in delayed diagnosis of HIV infection in children whose mothers are not perceived to be at risk.

Anti-CD2 receptor antibodies activate the HIV long terminal repeat in T lymphocytes

The CD2 T lymphocyte glycoprotein surface molecule mediates both cell to cell adhesion and T cell activation, two processes that are involved in the spread of HIV infection. Treatment of chronically HIV-infected PBMC with anti-CD2 mAb has been shown to induce the expression of infectious virus from these cultures. In this study we investigated the mechanisms whereby anti-CD2 antibodies stimulate viral production. We demonstrate that treatment of transiently transfected T lymphocytes with anti-CD2 antibodies results in activation of the HIV long terminal repeat. Furthermore, CAT assays using mutated HIV long terminal repeat-CAT constructs and gel shift assays demonstrate that this activation is dependent on the NF-kappa B enhancer. These studies suggest that interaction of CD2 with its natural ligand, LFA-3, may play a role in regulation of HIV expression.

Anti-CD2 receptor antibodies activate the HIV long terminal repeat in T lymphocytes

The CD2 T lymphocyte glycoprotein surface molecule mediates both cell to cell adhesion and T cell activation, two processes that are involved in the spread of HIV infection. Treatment of chronically HIV-infected PBMC with anti-CD2 mAb has been shown to induce the expression of infectious virus from these cultures. In this study we investigated the mechanisms whereby anti-CD2 antibodies stimulate viral production. We demonstrate that treatment of transiently transfected T lymphocytes with anti-CD2 antibodies results in activation of the HIV long terminal repeat. Furthermore, CAT assays using mutated HIV long terminal repeat-CAT constructs and gel shift assays demonstrate that this activation is dependent on the NF-kappa B enhancer. These studies suggest that interaction of CD2 with its natural ligand, LFA-3, may play a role in regulation of HIV expression.