Nature Medicine

Cholera remains a significant public health burden in many countries in sub-Saharan Africa, though the exact mechanisms of bacterial emergence and spread remain largely undefined. We generated genomic data from 763 Vibrio cholerae O1 isolates predominantly collected between 2019-2024 to create the largest dataset of V. cholerae genomes sequenced locally in Africa. This dataset enabled us to interrogate recent patterns of spread, including the rapid circulation of the AFR15 lineage associated wit...

The 2022 multi-country mpox outbreak, driven by MPXV Clade IIb has spread globally to over 100 countries, posing a new threat to global public health. Smallpox vaccination was discontinued in 1980 following global elimination with recent reports demonstrating evidence of asymptomatic infections particularly in individuals unlikely to have received a smallpox vaccine. To determine whether residual vaccination-derived immunity still shapes infection risk and to characterise population level burden...

The COVID-19 pandemic had a severe impact globally, yet African populations exhibited unexpectedly lower rates of severe disease and mortality. We investigated the potential role of pre-existing immunity in shaping the epidemiology of COVID-19 in Africa. Leveraging paired plasma and peripheral blood mononuclear cells collected from Senegalese female sex workers prior to the COVID-19 pandemic, we observed substantial levels of pre-existing cross-reactive immunity to SARS-CoV-2, stemming from prio...

Yellow fever virus (YFV), a mosquito-borne flavivirus that causes severe hemorrhagic disease, is endemic in parts of South America and Africa, yet genomic data from Sierra Leone is lacking despite ongoing surveillance. Using hybrid-capture metagenomic sequencing, we generated a complete 10,611-bp YFV genome (98% coverage) from an adult male patient who reported to the Kailahun Government Hospital with fever and muscle pain. Phylogenetic analysis assigned the genome to West African Clade V via th...

The COVID-19 pandemic surge has exceeded testing capacities in many parts of the world. We investigated the effectiveness of home temperature monitoring for early identification of COVID-19 patients. Study DesignWe compared home temperature measurements from a convenience sample of 1180 individuals who reported being test positive for SARS-CoV-2 to an age, sex, and location matched control group of 1249 individuals who had not tested positive. MethodsAll individuals monitored their temperature...

AO_SCPLOWBSTRACTC_SCPLOWEpidemiological data suggest that clade IIb monkeypox virus (MPXV) is readily transmitted during sexual contact, even before symptom onset. However, presymptomatic shedding of MPXV remains to be demonstrated. Here, we prospectively followed up 25 individuals after high-risk exposure to MPXV. Daily anorectal, genital, and saliva samples and weekly blood and oropharyngeal samples were collected along with clinical information. During follow-up, 12/18 (66.0%) sexual and 1/7 ...

With the development of high-efficacy vaccines against SARS-CoV-2, an urgent open question is whether currently available vaccines protect with similar efficacy against infection with SARS-CoV-2 variants of concern (VOC). Recent reports quantifying the extent by which VOC can evade vaccine immunity resulted in a range of estimates for the same VOC, which makes them difficult to interpret. One possible explanation for the discrepancies between different studies is an inconsistency in terms of the...

Five years before the 2022-2023 global mpox outbreak Nigeria reported its first cases in nearly 40 years, with the ongoing epidemic since driven by sustained human-to-human transmission. However, limited genomic data has left questions about the timing and origin of the mpox virus (MPXV) emergence. Here we generated 112 MPXV genomes from Nigeria from 2021-2023. We identify the closest zoonotic outgroup to the human epidemic in southern Nigeria, and estimate that the lineage transmitting from hum...

BackgroundOlder age is widely considered a risk factor for post-acute sequelae of SARS-CoV-2 infection (PASC), typically attributed to immunosenescence and inflammaging. However, whether this association reflects intrinsic biological ageing or accumulated comorbidity burden remains unclear, with implications for clinical risk stratification. MethodsWe conducted a retrospective cohort study using the Precision PASC Research Cohort (P2RC) from Mass General Brigham, comprising 133,792 COVID-19 pat...

Recent studies using data accrued from global SARS-CoV-2 vaccination efforts have demonstrated that breakthrough infections are correlated with levels of neutralizing antibodies. The decrease in neutralizing antibody titers of vaccinated individuals over time, combined with the emergence of more infectious variants of concern has resulted in waning vaccine efficacy against infection and a rise in breakthrough infections. Here we use a combination of neutralizing antibody measurements determined ...

We report in-concert dynamics of 18 key immune parameters, related to clinical, genetic and virological factors, in patients hospitalized with influenza across different severity levels. Influenza disease was associated with correlated increases in IL6/IL-8/MIP-1; cytokines and lower antibody responses. Robust activation of circulating T follicular helper cells (cTfhs) correlated with peak antibody-secreting cells (ASC) and influenza heamaglutinin-specific memory B-cell numbers, which phenotypic...

Person-to-person transmission of SARS-CoV-2 virus has triggered a global emergency because of its potential to cause life-threatening Covid-19 disease. By comparison to paucisymptomatic virus clearance by most individuals, Covid-19 has been proposed to reflect insufficient and/or pathologically exaggerated immune responses. Here we identify a consensus peripheral blood immune signature across 63 hospital-treated Covid-19 patients who were otherwise highly heterogeneous. The core signature conspi...

Covid-19 death has a different relationship with age than is the case for other severe respiratory pathogens. The Covid-19 death rate increases exponentially with age, and the main risk factors are age itself, as well as having underlying conditions such as hypertension, diabetes, cardiovascular disease, severe chronic respiratory disease and cancer. Furthermore, the almost complete lack of deaths in children suggests that infection alone is not sufficient to cause death; rather, one must have g...

Global genomic surveillance of SARS-CoV-2 has identified variants associated with increased transmissibility, neutralization resistance and disease severity. Here we report the emergence of the PANGO lineage C.1.2, detected at low prevalence in South Africa and eleven other countries. The emergence of C.1.2, associated with a high substitution rate, includes changes within the spike protein that have been associated with increased transmissibility or reduced neutralization sensitivity in SARS-Co...

The SARS-CoV-2 Omicron subvariant BA.3.2 descends from BA.3. It emerged 2 years after BA.3 ceased to circulate and differs by 39 spike mutations from BA.3. Similar to BA.2.86, which circulated at low levels before giving rise to JN.1, BA.3.2 shows a low but persistent circulation globally. Here, we characterize the phylogenetic origin, infection in cell culture, and neutralization of BA.3.2 using live virus and blood plasma samples collected in South Africa at different stages of the Covid-19 pa...

Omicron BA.2.86 subvariant differs from Omicron BA.2 as well as recently circulating variants by over 30 mutations in the spike protein alone. Here we report on the first isolation of the live BA.2.86 subvariant from a diagnostic swab collected in South Africa which we tested for escape from neutralizing antibodies and viral replication properties in cell culture. BA.2.86 did not have significantly more escape than Omicron XBB.1.5 from neutralizing immunity elicited by infection of Omicron subva...

In November 2024, a highly divergent BA.3-related SARS-CoV-2 lineage, designated BA.3.2, was detected in South Africa, marking the first appearance of a BA.3-derived lineage in over two years. Phylogenetic reconstruction places BA.3.2 on an extended branch descending from ancestral BA.3, with no intermediate genomes detected, consistent with a prolonged period of unsampled or isolated evolution. Molecular clock analyses indicate accelerated divergence characteristic of a saltation event, while p...

Mpox is a zoonotic viral disease caused by the monkeypox virus (MPXV). Human cases have been mainly restricted to the African continent until the worldwide multi-country outbreak unfolded in 2022. We reconstructed epidemiological links of MPXV infections using genomic epidemiology in Rio Grande do Sul State, southern Brazil, during 2022 and 2023. We detected five well-supported clades, three representing local transmission chains that were mostly restricted to the 2022 virus spread, one supporte...

The adoption of artificial intelligence in dermatology promises democratized access to healthcare, but model reliability depends on the quality and comprehensiveness of the data fueling these models. Despite rapid growth in publicly available dermatology images, the field lacks quantitative key performance indicators to measure whether new datasets expand clinical coverage or merely replicate what is already known. Here we present SkinMap, a multi-modal framework for the first comprehensive audi...

South Africa was among the first countries to detect the SARS-CoV-2 Omicron variant. Propelled by increased transmissibility and immune escape properties, Omicron displaced other globally circulating variants within 3 months of its emergence. Due to limited testing, Omicrons attenuated clinical severity, and an increased risk of reinfection, the size of the Omicron BA.1 and BA.2 subvariants (BA.1/2) wave remains poorly understood in South Africa and in many other countries. Using South African d...