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Correlates of protection: Vaccines against Ebola virus (EBOV) are difficult to test in humans due to the sporadic nature of EBOV outbreaks, so understanding correlates of protection in preclinical models is necessary. To this end, Meyer et al. tested five candidate mucosal EBOV vaccines in cynomolgus macaques and showed that, despite sharing the EBOV glycoprotein as an antigen, they varied in their ability to protect animals from the EBOV challenge. The authors interrogated correlates of protection and found that functional qualities of the antibody response, such as Fc-mediated effects, were associated with protection. In contrast, neutralizing antibody titers did not correlate with survival. Thus, looking beyond the presence of neutralizing antibodies may be necessary to understand the protective effect of EBOV vaccines. Although substantial progress has been made with Ebola virus (EBOV) vaccine measures, the immune correlates of vaccine-mediated protection remain uncertain. Here, five mucosal vaccine vectors based on human and avian paramyxoviruses provided nonhuman primates with varying degrees of protection, despite expressing the same EBOV glycoprotein (GP) immunogen. Each vaccine produced antibody responses that differed in Fc-mediated functions and isotype composition, as well as in magnitude and coverage toward GP and its conformational and linear epitopes. Differences in the degree of protection and comprehensive characterization of the response afforded the opportunity to identify which features and functions were elevated in survivors and could therefore serve as vaccine correlates of protection. Pairwise network correlation analysis of 139 immune- and vaccine-related parameters was performed to demonstrate relationships with survival. Total GP-specific antibodies, as measured by biolayer interferometry, but not neutralizing IgG or IgA titers, correlated with survival. Fc-mediated functions and the amount of receptor binding domain antibodies were associated with improved survival outcomes, alluding to the protective mechanisms of these vaccines. Therefore, functional qualities of the antibody response, particularly Fc-mediated effects and GP specificity, rather than simply magnitude of the response, appear central to vaccine-induced protection against EBOV. The heterogeneity of the response profile between the vaccines indicates that each vaccine likely exhibits its own protective signature and the requirements for an efficacious EBOV vaccine are complex. [ABSTRACT FROM AUTHOR]

The article focuses on the use of wastewater surveillance to track pathogens spread by fecal-oral transmission of cholera and polio, and mentions severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) wastewater surveillance. Topics discussed include pathogen detection enabled by wastewater monitoring, determination of the genomic sequencing, and expansion of waste-water surveillance capabilities.

The article explores why Covid-19 testing should be considered a public health tool for detecting severe acute respiratory syndrome coronavirus 2 (SARSCoV- 2), and controlling its transmission by investing in large-scale testing capacity. Topics include dominated and confused decision-making with regard to testing and the evaluation of tests is unsuitable; and identifying patients by performing test on symptomatic patients or asymptomatic individuals who are at high risk of infection.

In its largest outbreak, Ebola virus disease is spreading through Guinea, Liberia, Sierra Leone, and Nigeria. We sequenced 99 Ebola virus genomes from 78 patients in Sierra Leone to ~2000x coverage. We observed a rapid accumulation of interhost and intrahost genetic variation, allowing us to characterize patterns of viral transmission over the initial weeks of the epidemic. This West African variant likely diverged from central African lineages around 2004, crossed from Guinea to Sierra Leone in May 2014, and has exhibited sustained human-to-human transmission subsequently, with no evidence of additional zoonotic sources. Because many of the mutations alter protein sequences and other biologically meaningful targets, they should be monitored for impact on diagnostics, vaccines, and therapies critical to outbreak response. [ABSTRACT FROM AUTHOR]

The article discusses research that suggests that outbreaks of Lassa, Marburg, and Ebola hemorrhagic fever viruses in Africa can be attributed to improvements in the diagnosis and detection of common and widespread diseases, rather than evidence of emerging pathogens. It is noted that seroprevalence surveys indicate widespread exposure to these viruses in sub-Saharan Africa, possibly from contact with animal disease reservoirs such as the Mastomys natalensis mouse, fruit bat, and nonhuman primates. Other topics include analysis of the evolutionary divergence of these viruses pointing to ancient origins, genomic analysis of human adaptations to hemorrhagic fever viruses, and viral research at community health clinics in Sierra Leone and Nigeria.

Hoenen et al. (Reports, 3 April 2015, p. 117; published online 26 March) suggested that the Ebola virus Makona responsible for the West African epidemic evolved more slowly than previously reported. We show that this was based on corrupted data. An erratum provided a rate compatible with the initial and later, more precise, estimates but did not correctly state the nature of the error. [ABSTRACT FROM AUTHOR]

Understanding the circumstances that lead to pandemics is important for their prevention. We analyzed the genomic diversity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) early in the coronavirus disease 2019 (COVID-19) pandemic. We show that SARS-CoV-2 genomic diversity before February 2020 likely comprised only two distinct viral lineages, denoted "A" and "B." Phylodynamic rooting methods, coupled with epidemic simulations, reveal that these lineages were the result of at least two separate cross-species transmission events into humans. The first zoonotic transmission likely involved lineage B viruses around 18 November 2019 (23 October to 8 December), and the separate introduction of lineage A likely occurred within weeks of this event. These findings indicate that it is unlikely that SARS-CoV-2 circulated widely in humans before November 2019 and define the narrow window between when SARS-CoV-2 first jumped into humans and when the first cases of COVID-19 were reported. As with other coronaviruses, SARS-CoV-2 emergence likely resulted from multiple zoonotic events.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally, with >365,000 cases in California as of 17 July 2020. We investigated the genomic epidemiology of SARS-CoV-2 in Northern California from late January to mid-March 2020, using samples from 36 patients spanning nine counties and the Grand Princess cruise ship. Phylogenetic analyses revealed the cryptic introduction of at least seven different SARS-CoV-2 lineages into California, including epidemic WA1 strains associated with Washington state, with lack of a predominant lineage and limited transmission among communities. Lineages associated with outbreak clusters in two counties were defined by a single base substitution in the viral genome. These findings support contact tracing, social distancing, and travel restrictions to contain the spread of SARS-CoV-2 in California and other states., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)