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"Mohammed, Hamish"
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Effectiveness of one dose of MVA–BN smallpox vaccine against mpox in England using the case-coverage method: an observational study
2023
The UK experienced a national outbreak of mpox (formerly known as monkeypox) disease that started in May, 2022, as did many other countries worldwide, with case numbers rising rapidly, mainly among gay, bisexual, and other men who have sex with men (GBMSM). To control the outbreak, Modified Vaccinia Ankara–Bavaria Nordic (MVA–BN), an attenuated smallpox vaccine, was offered to at-risk GBMSM. We aimed to assess the effectiveness of a single MVA–BN dose against symptomatic mpox disease in at-risk GBMSM.
In this case-coverage study, mpox cases in England were sent questionnaires collecting information on demographics, vaccination history, symptoms, and sexual orientation. Returned questionnaires were linked to laboratory data and a public health case management system (HP Zone) to obtain additional information on symptom onset and specimen date. Cases with a rash onset date (or alternative proxy) between July 4 and Oct 9, 2022, were included. Females, heterosexual men, and those with missing vaccination information were excluded. Vaccine effectiveness was calculated using the case-coverage method in which vaccine coverage among cases is compared with coverage in the eligible population, estimated from doses given to GBMSM and the estimated size of at-risk GBMSM. Sensitivity analyses included an increase and decrease of 20% differences in the estimated high-risk GBMSM population size.
By Nov 3, 2022, 1102 people had responded to questionnaires, of which 739 were excluded (52 females or self-declared male heterosexuals, 590 with an index date outside of the study period, and 97 missing a vaccination date). 363 cases were included in the analyses. Vaccine uptake among eligible GBMSM increased steadily from July, 2022, reaching 47% by Oct 9, 2022. Of the 363 confirmed cases, eight cases either did occur or were likely to have occurred at least 14 days after vaccination, 32 within 0–13 days after vaccination, and the rest were unvaccinated. The estimated vaccine effectiveness against symptomatic mpox at least 14 days after a single dose was 78% (95% CI 54 to 89) ranging from 71 to 85 in sensitivity analyses. Vaccine effectiveness within 0–13 days after vaccination was –4% (95% CI –50 to 29).
A single MVA–BN dose was highly protective against symptomatic mpox disease among at-risk GBMSM, making it a useful tool for mpox outbreak control when rapid protection is needed. For cases in which numbers at highest risk of infection exceed vaccine supply, there might be benefit in prioritising delivery of first doses.
UK Health Security Agency.
Journal Article
Epidemiology of Early Monkeypox Virus Transmission in Sexual Networks of Gay and Bisexual Men, England, 2022
by
Prochazka, Mateo
,
Mohammed, Hamish
,
Paranthaman, Karthik
in
Bias
,
Bisexuality
,
Case management
2022
After community transmission of monkeypox virus was identified in Europe, interviews of 45 case-patients from England indicated transmission in international sexual networks of gay and bisexual men since April 2022. Interventions targeting sex-on-premises venues, geospatial dating applications, and sexual health services are likely to be critical for outbreak control.
Journal Article
Rebound of Gonorrhea after Lifting of COVID-19 Preventive Measures, England
by
Mohammed, Hamish
,
Charles, Hannah
,
Migchelsen, Stephanie J.
in
Age groups
,
Chlamydia
,
Control
2024
After lifting of all COVID-19 preventive measures in England in July 2021, marked, widespread increases in gonorrhea diagnoses, but not testing numbers, were observed, particularly in persons 15-24 years of age. Continued close surveillance and public health messaging to young persons are needed to control and prevent gonorrhea transmission.
Journal Article
Mpox Epidemiology and Vaccine Effectiveness, England, 2023
2024
Reported mpox cases in England continued at a low but steady frequency during 2023. Of 137 cases reported in 2023, approximately half were acquired overseas and half were in vaccinated persons. Estimated effectiveness of 2-dose vaccine was 80%, and no vaccinated mpox patient was hospitalized.
Journal Article
Mpox Diagnosis, Behavioral Risk Modification, and Vaccination Uptake among Gay, Bisexual, and Other Men Who Have Sex with Men, United Kingdom, 2022
2024
During the 2022 multicountry mpox outbreak, the United Kingdom identified cases beginning in May. UK cases increased in June, peaked in July, then rapidly declined after September 2022. Public health responses included community-supported messaging and targeted mpox vaccination among eligible gay, bisexual, and other men who have sex with men (GBMSM). Using data from an online survey of GBMSM during November-December 2022, we examined self-reported mpox diagnoses, behavioral risk modification, and mpox vaccination offer and uptake. Among 1,333 participants, only 35 (2.6%) ever tested mpox-positive, but 707 (53%) reported behavior modification to avoid mpox. Among vaccine-eligible GBMSM, uptake was 69% (95% CI 65%-72%; 601/875) and was 92% (95% CI 89%-94%; 601/655) among those offered vaccine. GBMSM self-identifying as bisexual, reporting lower educational qualifications, or identifying as unemployed were less likely to be vaccinated. Equitable offer and provision of mpox vaccine are needed to minimize the risk for future outbreaks and mpox-related health inequalities.
Journal Article
Genomic and Phenotypic Variability in Neisseria gonorrhoeae Antimicrobial Susceptibility, England
by
Cole, Michelle J.
,
Pitt, Rachel
,
Harris, Simon
in
Adult
,
Anti-Bacterial Agents - pharmacology
,
Anti-Bacterial Agents - therapeutic use
2020
Antimicrobial resistance (AMR) in Neisseria gonorrhoeae is a global concern. Phylogenetic analyses resolve uncertainties regarding genetic relatedness of isolates with identical phenotypes and inform whether AMR is due to new mutations and clonal expansion or separate introductions by importation. We sequenced 1,277 isolates with associated epidemiologic and antimicrobial susceptibility data collected during 2013-2016 to investigate N. gonorrhoeae genomic variability in England. Comparing genetic markers and phenotypes for AMR, we identified 2 N. gonorrhoeae lineages with different antimicrobial susceptibility profiles and 3 clusters with elevated MICs for ceftriaxone, varying mutations in the penA allele, and different epidemiologic characteristics. Our results indicate N. gonorrhoeae with reduced antimicrobial susceptibility emerged independently and multiple times in different sexual networks in England, through new mutation or recombination events and by importation. Monitoring and control for AMR in N. gonorrhoeae should cover the entire population affected, rather than focusing on specific risk groups or locations.
Journal Article
Transcriptomic Profiling of Diverse Aedes aegypti Strains Reveals Increased Basal-level Immune Activation in Dengue Virus-refractory Populations and Identifies Novel Virus-vector Molecular Interactions
by
Jupatanakul, Natapong
,
Mohammed, Hamish
,
Kang, Seokyoung
in
Aedes - genetics
,
Aedes - immunology
,
Aedes - virology
2013
Genetic variation among Aedes aegypti populations can greatly influence their vector competence for human pathogens such as the dengue virus (DENV). While intra-species transcriptome differences remain relatively unstudied when compared to coding sequence polymorphisms, they also affect numerous aspects of mosquito biology. Comparative molecular profiling of mosquito strain transcriptomes can therefore provide valuable insight into the regulation of vector competence. We established a panel of A. aegypti strains with varying levels of susceptibility to DENV, comprising both laboratory-maintained strains and field-derived colonies collected from geographically distinct dengue-endemic regions spanning South America, the Caribbean, and Southeast Asia. A comparative genome-wide gene expression microarray-based analysis revealed higher basal levels of numerous immunity-related gene transcripts in DENV-refractory mosquito strains than in susceptible strains, and RNA interference assays further showed different degrees of immune pathway contribution to refractoriness in different strains. By correlating transcript abundance patterns with DENV susceptibility across our panel, we also identified new candidate modulators of DENV infection in the mosquito, and we provide functional evidence for two potential DENV host factors and one potential restriction factor. Our comparative transcriptome dataset thus not only provides valuable information about immune gene regulation and usage in natural refractoriness of mosquito populations to dengue virus but also allows us to identify new molecular interactions between the virus and its mosquito vector.
Journal Article
Epidemiology of Confirmed COVID-19 Deaths in Adults, England, March–December 2020
by
Mohammed, Hamish
,
Brown, Alison E.
,
Beebeejaun, Kazim
in
coronavirus disease
,
Coronaviruses
,
COVID-19
2021
Of the 58,186 coronavirus deaths among adults in England during March-December 2020, 77% occurred in hospitals, 93% were in patients >60 years, and 91% occurred within 28 days of positive specimen. Cumulative mortality rates were highest among persons of Black, Asian, other, or mixed ethnicities and in socioeconomically deprived areas.
Journal Article
Evaluating the Implementation of Online Postal Self-Sampling for Sexually Transmitted Infections in England: Multisite Qualitative Study
by
Copas, Andrew
,
Mohammed, Hamish
,
Crundwell, David
in
Case studies
,
Clinics
,
COVID-19 - epidemiology
2025
Online postal self-sampling (OPSS) allows service users to screen for sexually transmitted infections (STIs) by ordering a self-sampling kit online, taking their own samples, returning them to a laboratory for testing, and receiving their results remotely. OPSS availability and use has increased in both the United Kingdom and globally the past decade but has been adopted in different regions of England at different times, with different models of delivery. It is not known why certain models were decided on or how implementation strategies have influenced outcomes, including the sustainability of OPSS in sexual health service delivery.
This study aims to evaluate the implementation of OPSS in 3 case study areas of England, with a focus on the sustainability of implementation and the relationship between implementation strategies and outcomes.
Qualitative data collection methods were used: interviews with staff and stakeholders involved in the implementation and delivery of OPSS, analysis of local implementation and national policy documents, and observations in sexual health clinics. Analysis of interviews and observations was undertaken using qualitative implementation science frameworks, including normalization process theory, the Consolidated Framework for Implementation Research, and the major system change framework. Documentary sources were used primarily to map processes over time and triangulate against interview and observational evidence.
Across the 3 case study areas, 60 staff and stakeholders were interviewed, 12 observations were conducted, and data from 86 documents were collated. Rather than being a discrete digital health intervention, we found that OPSS was part of-or occurred parallel to-major system changes in all areas. These changes were driven by budgetary pressures in all areas, but there was variation in other objectives used to rationalize the decision to adopt. The financial context and organizational relationships in each area determined the implementation strategies available to decision makers, how these strategies were enacted, and, in turn, led to different outcomes at different time points. OPSS implementation was not a one-off outcome but an ongoing process in response to changes in context, which in turn affected how staff perceived and engaged with OPSS. The COVID-19 pandemic had profound but divergent effects on OPSS implementation in each area, accelerating it in some contexts and reversing it in others.
In this multisite case study, OPSS implementation was part of systems change to address a wider problem of insufficient funding to deliver sexual health care. Decisions about implementing OPSS were made before sufficient evidence was available to effectively guide the process. The resultant unintended consequences need acknowledgment to enable future commissioners and sexual health services to optimize sexual health service provision.
RR2-10.1136/bmjopen-2022-067170.
Journal Article
How does online postal self-sampling (OPSS) shape access to testing for sexually transmitted infections (STIs)? A qualitative study of service users
by
Mercer, Catherine H.
,
Mohammed, Hamish
,
Crundwell, David
in
Accelerated tests
,
Access
,
Adolescent
2024
Background
Sexually transmitted infections (STIs) are a serious public health issue in many countries. Online postal self-sampling (OPSS) is increasingly used to test for STIs, a trend accelerated by the COVID-19 pandemic. There remains limited understanding of how service users experience OPSS and what leads them to access it over clinic-based services, or vice versa. This research seeks to address these gaps, by undertaking a large qualitative study which sits within the ASSIST study, a mixed-methods, realist evaluation of OPSS.
Methods
Participants were recruited via clinic-based and online sexual health services in three case study areas in England. Purposive sampling was used to over-represent populations disproportionately affected by poor sexual health: young people; people of colour; men who have sex with men; and trans and non-binary people. Semi-structured interviews were analysed using Levesque’s conceptual framework of access to healthcare.
Results
We interviewed 100 service users. Participants typically became aware of OPSS from sexual health services, the internet or word of mouth. Acceptability of OPSS was facilitated by the perceived privacy it offered over clinic-based services, which some participants found embarrassing to access. OPSS also enabled participants to overcome barriers to reaching clinic-based services, such as a lack of appointment availability, although difficulty obtaining OPSS kits in some areas undermined this. As all services in our case study areas were free to use, affordability did not significantly shape access, although OPSS enabled some participants to avoid costs associated with travelling to clinic-based services. Participants were usually able to engage with OPSS, finding it easy to use and reliable, although blood self-sampling was challenging for most. Participants valued the support offered by clinic-based services beyond STI testing, including the opportunity to access contraception or ask staff questions, and felt this was more appropriate when they had specific concerns about their sexual health, such as STI symptoms.
Conclusions
Our findings constitute one of the largest qualitative studies to have explored OPSS and offer valuable insights to providers. OPSS shapes access to STI testing in a number of ways, including facilitating access in many circumstances, but users also want to retain access to clinic-based services, particularly for when they believe they need support beyond STI testing.
Journal Article