Ezra Linley

In the summer of 2022, a large outbreak of Monkeypox virus (MPXV) cases occurred globally. By December 2022, a total of 3,582 Mpox cases had been confirmed within the UK. As a result, the Modified Vaccinia Ankara-Bavarian Nordic (“IMVANEX”) vaccine was offered to high-risk groups to protect against the spread of the virus. This outbreak led to the development of multiple serological assays to aid the current understanding of Mpox immunology. This study assessed the performance of a multiplexed solid-phase electrochemiluminescence (Meso Scale Discovery (MSD)) immunoassay for simultaneous detection of antibodies against MPXV A29, A35, B6, E8, and M1 antigens, along with the corresponding Vaccina Virus (VACV) homologues A27, A33, B5, D8, and L1. Sensitivity and specificity were evaluated with paediatric negatives (n=215), pre- and post-IMVANEX vaccinated (n=80) and MPXV (2022 Clade IIb outbreak, n=39) infected serum samples. The overall Orthopoxvirus multiplex assay demonstrated high specificity ranging from 75.68% (CI: 69.01-81.29) - 95.98% (CI:92.54-97.87) and sensitivity from 62.11% (CI:52.06-71.21) - 98.59% (CI:92.44% - 99.93%) depending on the Orthopoxvirus antigen, either used singularly or combined. Additionally, preferential binding was observed between Mpox-infected individuals and MPXV antigens, whilst vaccinated individuals exhibited increased binding to VACV antigens. These results highlight the differential binding patterns between antigen homologues in closely related viruses. Using this assay, we show that the Orthopoxvirus MSD assay is highly sensitive in detecting IgG titres for vaccinated sera ≥24-days post dose one and ≥14-days post dose two for all antigens within the assay except for MPXV A29 and VACV A27. A similar trend was observed with convalescent sera, although differing antigens demonstrate stronger sensitivities. Overall, this assay has the capability to accurately assess antibody titres for multiple relevant MPXV and VACV antigens post infection and post vaccination, demonstrating its utility in understanding immune responses to Orthopox viruses in current and future outbreaks, and assessing the immunogenicity of new generation Orthopox and Mpox-specific vaccinations.

Background: Prepandemic sentinel surveillance focused on improved management of winter pressures, with influenza-like illness (ILI) being the key clinical indicator. The World Health Organization (WHO) global standards for influenza surveillance include monitoring acute respiratory infection (ARI) and ILI. The WHO’s mosaic framework recommends that the surveillance strategies of countries include the virological monitoring of respiratory viruses with pandemic potential such as influenza. The Oxford-Royal College of General Practitioner Research and Surveillance Centre (RSC) in collaboration with the UK Health Security Agency (UKHSA) has provided sentinel surveillance since 1967, including virology since 1993. Objective: We aim to describe the RSC’s plans for sentinel surveillance in the 2023-2024 season and evaluate these plans against the WHO mosaic framework. Methods: Our approach, which includes patient and public involvement, contributes to surveillance objectives across all 3 domains of the mosaic framework. We will generate an ARI phenotype to enable reporting of this indicator in addition to ILI. These data will support UKHSA’s sentinel surveillance, including vaccine effectiveness and burden of disease studies. The panel of virology tests analyzed in UKHSA’s reference laboratory will remain unchanged, with additional plans for point-of-care testing, pneumococcus testing, and asymptomatic screening. Our sampling framework for serological surveillance will provide greater representativeness and more samples from younger people. We will create a biomedical resource that enables linkage between clinical data held in the RSC and virology data, including sequencing data, held by the UKHSA. We describe the governance framework for the RSC. Results: We are co-designing our communication about data sharing and sampling, contextualized by the mosaic framework, with national and general practice patient and public involvement groups. We present our ARI digital phenotype and the key data RSC network members are requested to include in computerized medical records. We will share data with the UKHSA to report vaccine effectiveness for COVID-19 and influenza, assess the disease burden of respiratory syncytial virus, and perform syndromic surveillance. Virological surveillance will include COVID-19, influenza, respiratory syncytial virus, and other common respiratory viruses. We plan to pilot point-of-care testing for group A streptococcus, urine tests for pneumococcus, and asymptomatic testing. We will integrate test requests and results with the laboratory-computerized medical record system. A biomedical resource will enable research linking clinical data to virology data. The legal basis for the RSC’s pseudonymized data extract is The Health Service (Control of Patient Information) Regulations 2002, and all nonsurveillance uses require research ethics approval. Conclusions: The RSC extended its surveillance activities to meet more but not all of the mosaic framework’s objectives. We have introduced an ARI indicator. We seek to expand our surveillance scope and could do more around transmissibility and the benefits and risks of nonvaccine therapies.

In early 2022, a cluster of Monkeypox (now termed MPOX) virus (MPXV) cases were identified within the UK with no prior travel history to MPXV-endemic regions, suggesting localised transmission of MPXV within the UK. Subsequently, cases were identified in several other non-endemic countries and currently exceed 80,000 worldwide, primarily affecting gay, bisexual, and other men who have sex with men. Public health agencies worldwide have offered the IMVANEX Smallpox vaccination to these individuals to provide protection and limit the spread of MPXV. We have developed a comprehensive array of ELISA assays to study poxvirus-induced antibodies, utilising 24 MPXV and 3 Vaccinia virus (VACV) recombinant antigens. Panels of serum samples from individuals with one, two, or three doses of IMVANEX or ACAM2000 (Modified Vaccinia Ankara (MVA)) vaccination, and those with prior MPOX infection were tested against these antigens, with Pearson correlation, principal component analysis and receiver operator curve statistics used to further elucidate antigenic responses to pox-virus infection. Furthermore, using our data, we demonstrated the development of a pooled antigen ELISA that can reliably detect antibody responses induced by Smallpox vaccination or MPXV infection. Using diverse poxvirus antigen ELISAs, we observe that one dose of Smallpox vaccination induces a low number of antibodies, primarily against MPXV B2, with a second dose inducing considerably higher antibody responses against B2R but also to other MPXV antigens such as B5, E8, M1, and A35. Prior MPXV infection, both Clades IIa and IIb, induce variable responses, but similarly induce antibody responses to poxvirus antigens observed in Smallpox-vaccinated individuals, and additionally responses to MPXV A27, A29 and H3. Principal component and Pearson correlation matrix identified MPXV A27 as a differential between IMVANEX and MPOX-infected individuals, whilst MPXV M1 (VACV L1) is likely a serological marker of IMVANEX-vaccination. When using recombinant MPXV/VACV protein homologues, we also observe a difference in antigen binding, with variability based on the individual’s originating infection/vaccination. Using a pooled-antigen ELISA, we also demonstrate a sensitivity of 97.14% (95% CI:91.93-99.22) and specificity of 98.23% (96.67-99.07) in detecting poxvirus antibodies with applicability to measuring longitudinal antibody responses post-vaccination/post-MPXV infection. Here, we show that both MPXV-infected or Smallpox-vaccinated individuals mount antibodies able to bind a diverse but core set of poxvirus antigens, with implications for future vaccine (e.g., mRNA-based) and therapeutic (e.g., monoclonal antibodies) targets. We identify low levels of antibodies observed in those post dose one IMVANEX, but considerably higher levels of antibodies post dose two. We also demonstrate that homologous VACV and MPXV antigens may offer a mechanism for discriminating between vaccinated and MPXV-infected individuals through differential binding, aiding in serosurveillance and future immunology studies.

Background: The Oxford-Royal College of General Practitioners (RCGP) Research and Surveillance Centre (RSC) is one of Europe’s oldest sentinel systems, working with the UK Health Security Agency (UKHSA) and its predecessor bodies for 55 years. Its surveillance report now runs twice weekly, supplemented by online observatories. In addition to conducting sentinel surveillance from a nationally representative group of practices, the RSC is now also providing data for syndromic surveillance. Objective: The aim of this study was to describe the cohort profile at the start of the 2021-2022 surveillance season and recent changes to our surveillance practice. Methods: The RSC’s pseudonymized primary care data, linked to hospital and other data, are held in the Oxford-RCGP Clinical Informatics Digital Hub, a Trusted Research Environment. We describe the RSC’s cohort profile as of September 2021, divided into a Primary Care Sentinel Cohort (PCSC)—collecting virological and serological specimens—and a larger group of syndromic surveillance general practices (SSGPs). We report changes to our sampling strategy that brings the RSC into alignment with European Centre for Disease Control guidance and then compare our cohort’s sociodemographic characteristics with Office for National Statistics data. We further describe influenza and COVID-19 vaccine coverage for the 2020-2021 season (week 40 of 2020 to week 39 of 2021), with the latter differentiated by vaccine brand. Finally, we report COVID-19–related outcomes in terms of hospitalization, intensive care unit (ICU) admission, and death. Results: As a response to COVID-19, the RSC grew from just over 500 PCSC practices in 2019 to 1879 practices in 2021 (PCSC, n=938; SSGP, n=1203). This represents 28.6% of English general practices and 30.59% (17,299,780/56,550,136) of the population. In the reporting period, the PCSC collected >8000 virology and >23,000 serology samples. The RSC population was broadly representative of the national population in terms of age, gender, ethnicity, National Health Service Region, socioeconomic status, obesity, and smoking habit. The RSC captured vaccine coverage data for influenza (n=5.4 million) and COVID-19, reporting dose one (n=11.9 million), two (n=11 million), and three (n=0.4 million) for the latter as well as brand-specific uptake data (AstraZeneca vaccine, n=11.6 million; Pfizer, n=10.8 million; and Moderna, n=0.7 million). The median (IQR) number of COVID-19 hospitalizations and ICU admissions was 1181 (559-1559) and 115 (50-174) per week, respectively. Conclusions: The RSC is broadly representative of the national population; its PCSC is geographically representative and its SSGPs are newly supporting UKHSA syndromic surveillance efforts. The network captures vaccine coverage and has expanded from reporting primary care attendances to providing data on onward hospital outcomes and deaths. The challenge remains to increase virological and serological sampling to monitor the effectiveness and waning of all vaccines available in a timely manner.