Shamez Ladhani

Shamez Ladhani
Public Health England | HPA · Immunisation, Hepatitis, and Blood Safety department

MRCPCH PhD

About

475
Publications
56,728
Reads
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15,695
Citations
Additional affiliations
September 2009 - present
St George's, University of London
Position
  • Lecturer

Publications

Publications (475)
Article
University students are a critical group for vaccination programmes against COVID-19, meningococcal disease (MenACWY) and measles, mumps and rubella (MMR). We aimed to evaluate risk factors for vaccine hesitancy and views about on-campus vaccine delivery among university students. Data were obtained through a cross-sectional anonymous online questi...
Article
During July-December 2021, after COVID-19 restrictions were removed in England, invasive pneumococcal disease incidence in children <15 years of age was higher (1.96/100,000 children) than during the same period in 2020 (0.7/100,000 children) and in prepandemic years 2017-2019 (1.43/100,000 children). Childhood vaccine coverage should be maintained...
Article
SARS‐CoV‐2 infection in pregnancy is associated with increased risk of adverse maternal and perinatal outcomes including preterm birth, pre‐eclampsia, stillbirth, admission to intensive care unit and death. Vaccines are highly effective in preventing severe COVID‐19, however there are limited data on COVID‐19 vaccines in pregnancy. This study aimed...
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Full-text available
Background Little is known about the views of adolescents returning to secondary school during the current COVID-19 pandemic. Methods In September 2020, the UK Health Security Agency (UKHSA), formerly known as Public Health England (PHE),recruited staff and students in secondary schools to provide nasal swabs, oral fluid and blood samples for SARS...
Preprint
The Omicron variant of SARS-CoV-2 is now globally dominant but despite high prevalence little is known regarding the immune response in children. We determined the antibody and cellular immune response following Omicron infection in children aged 6-14 years and related this to prior SARS-CoV-2 infection and vaccination status. Primary Omicron infec...
Preprint
Background Risk factors for infection and, therefore, antibody positivity rates will be different in children compared to adults. We aim to estimate national and regional prevalence of SARS-CoV-2 antibodies in primary (4-11-year-olds) and secondary (11-15-year-olds) school children between 10 November and 10 December 2021. Methods Cross-sectional...
Article
Little is known about the MIS-C risk with different SARS-CoV-2 variants. In Southeast England, MIS-C rates per confirmed SARS-CoV-2 infections in 0-16 years-olds were 56% lower (rate ratio, 0.34; 95%CI, 0.23-0.50) during pre-vaccine Delta, 66% lower (0.44; 0.28-0.69) during post-vaccine Delta and 95% lower (0.05; 0.02-0.10) during the Omicron perio...
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Full-text available
Objectives To analyse clinical meningococcal strains associated with meningococcal septic arthritis cases in England and Wales, and to identify associations between patient age, the synovial joint affected and strain characteristics. Methods IMD cases confirmed by the Meningococcal Reference Unit (UK Health Security Agency) between January 2010 an...
Preprint
BACKGROUND n.a OBJECTIVE COVID-19 data have been generated across the UK as a by-product of clinical care and public health provision, and numerous bespoke and repurposed research endeavours. Analysis of these data has underpinned the UK’s response to the pandemic and informed public health policies and clinical guidelines. However, these data are...
Article
Background: Pneumococcal conjugate vaccines covering 10 (PCV10) and 13 (PCV13) serotypes have been introduced in the infant immunization schedule of most European countries in 2010-11. To provide additional real-life data, we measured the effectiveness of PCV10 and PCV13 against invasive pneumococcal disease (IPD) in children of 12 European sites...
Preprint
Background In England, the emergence the more transmissible SARS-CoV-2 variant Alpha (B.1.1.7) led to a third national lockdown from December 2020, including restricted attendance at schools. Nurseries, however, remained fully open. COVID-19 outbreaks (≥ 2 laboratory-confirmed cases within 14 days) in nurseries and assess the risk of SARS-CoV-2 inf...
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Safety and effectiveness of COVID-19 vaccines during pregnancy is a particular concern affecting vaccination uptake by this vulnerable group. Here we evaluated evidence from 23 studies including 117,552 COVID-19 vaccinated pregnant people, almost exclusively with mRNA vaccines. We show that the effectiveness of mRNA vaccination against RT-PCR confi...
Preprint
Objectives This systematic review and meta-analysis aimed to estimate the age-specific proportion of asymptomatic SARS-CoV-2 infected persons by year of age. Methods We searched PubMed, Embase, medRxiv and Google Scholar on 10 September 2020 and 1 March 2021. We included studies conducted during January to October 2020, prior to routine vaccinatio...
Preprint
Importance Predictive models can help identify SARS-CoV-2 patients at greatest risk of post-COVID sequelae and direct them towards appropriate care. Objective To develop and internally validate a model to predict children and young people most likely to experience at least one impairing physical symptom 3 months after a SARS-CoV-2 PCR-test and to...
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Background We hypothesised that the clinical characteristics of hospitalised children and young people (CYP) with SARS-CoV-2 in the UK second wave (W2) would differ from the first wave (W1) due to the alpha variant (B.1.1.7), school reopening and relaxation of shielding. Methods Prospective multicentre observational cohort study of patients <19 ye...
Preprint
Introduction Streptococcus pneumoniae epidemiology is changing in response to vaccination and some data suggest empyema incidence is increasing. However, differences exist between UK and USA studies. We describe trends in the clinical phenotype of adult pneumococcal pleural infection, including simple parapneumonic effusions (SPE) in the pneumococc...
Preprint
Paediatric Inflammatory Multisystem Syndrome (PIMS-TS, also known as MIS-C) typically occurs 2-6 weeks after exposure to SARS-CoV-2. Early estimates suggested a risk of PIMS-TS of 1 in 3-4000 infected children. Whether this risk is sustained with new SARS-CoV-2 variants remains unknown. We utilised prospective data from the NHS South Thames Paediat...
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Background: A rapid increase in coronavirus disease 2019 (Covid-19) cases due to the omicron (B.1.1.529) variant of severe acute respiratory syndrome coronavirus 2 in highly vaccinated populations has aroused concerns about the effectiveness of current vaccines. Methods: We used a test-negative case-control design to estimate vaccine effectivene...
Article
Full-text available
Background The role of educational settings in SARS-CoV-2 infection and transmission remains controversial. We investigated SARS-CoV-2 infection, seroprevalence, and seroconversion rates in secondary schools during the 2020/21 academic year, which included the emergence of the more transmissible alpha and delta variants, in England. Methods The UK...
Article
Full-text available
Background Reinfection after primary SARS-CoV-2 infection is uncommon in adults, but little is known about the risks, characteristics, severity, or outcomes of reinfection in children. We aimed to assess the risk of SARS-CoV-2 reinfection in children and compare this with the risk in adults, by analysis of national testing data for England. Method...
Preprint
In contrast to the increasing levels of high avidity S antibody measured by the Roche assay in the first 6 months following natural infection, marked waning is seen post 2 or 3 doses of vaccine. Although the kinetics differ between those with vaccine-induced immunity compared to those infected prior to vaccination (hybrid immunity), waning rates ap...
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Background Following the full re-opening of schools in England and emergence of the SARS-CoV-2 Alpha variant, we investigated the risk of SARS-CoV-2 infection in students and staff who were contacts of a confirmed case in a school bubble (school groupings with limited interactions), along with their household members. Methods Primary and secondary...
Preprint
Background University students are a critical group for vaccination programmes against COVID-19, meningococcal disease (MenACWY), and measles, mumps and rubella (MMR). We aimed to evaluate risk factors for vaccine hesitancy (refusal or intention to refuse a vaccine) and views of university students about on-campus vaccine delivery. Methods Cross-s...
Article
Full-text available
Background We describe post-COVID symptomatology in a non-hospitalised, national sample of adolescents aged 11–17 years with PCR-confirmed SARS-CoV-2 infection compared with matched adolescents with negative PCR status. Methods In this national cohort study, adolescents aged 11–17 years from the Public Health England database who tested positive f...
Article
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Background Vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (Covid-19), have been used since December 2020 in the United Kingdom. Real-world data have shown the vaccines to be highly effective against Covid-19 and related severe disease and death. Vaccine effectiveness may...
Article
Serum samples were collected pre- and post-booster vaccination with Comirnaty in 626 participants (aged ≥ 50 years) who had received two Comirnaty doses < 30 days apart, two Comirnaty doses ≥ 30 days apart or two Vaxzevria doses ≥ 30 days apart. Irrespective of primary vaccine type or schedule, spike antibody GMTs peaked 2–4 weeks after second dose...
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We report on the first large-scale assessment of the suitability of oral fluids for detection of SARS-CoV-2 antibody obtained from healthy children attending school. The sample type (gingiva-crevicular fluid, which is a transudate of blood but is not saliva) can be self collected.
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Full-text available
Objective: To assess the incidence of maternal group B streptococcal (GBS) infection in England DESIGN: Population surveillance augmented through data linkage. Setting: England POPULATION: All pregnant women accessing the National Health Service (NHS) in England METHODS: Invasive GBS (iGBS) infections during pregnancy or within six weeks of chil...
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Full-text available
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is rarely fatal in children and young people (CYP, <18 years old), but quantifying the risk of death is challenging because CYP are often infected with SARS-CoV-2 exhibiting no or minimal symptoms. To distinguish between CYP who died as a result of SARS-CoV-2 infection and those...
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Identifying which children and young people (CYP) are most vulnerable to serious infection due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is important to guide protective interventions. To address this question, we used data for all hospitalizations in England among 0–17 year olds from 1 February 2019 to 31 January 2021. We exa...
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SARS-CoV-2 infection is generally mild or asymptomatic in children but a biological basis for this outcome is unclear. Here we compare antibody and cellular immunity in children (aged 3–11 years) and adults. Antibody responses against spike protein were high in children and seroconversion boosted responses against seasonal Beta-coronaviruses throug...
Preprint
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Background The role of children and young people (CYP) in transmission of SARS-CoV-2 in household and educational settings remains unclear. We undertook a systematic review and meta-analysis of contact-tracing and population-based studies at low risk of bias. Methods We searched 4 electronic databases on 28 July 2021 for contact-tracing studies and...
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Background There are limited data on immune responses to heterologous COVID–19 immunisation schedules, especially following an extended ≥12–week interval between doses. Methods SARS–CoV–2 infection–naïve and previously–infected adults receiving ChAd–BNT (ChAdOx1 nCoV–19, AstraZeneca followed by BNT162b2, Pfizer–BioNTech) or BNT–ChAd as part of the...
Preprint
Full-text available
Background A rapid increase in cases due to the SARS-CoV-2 Omicron (B.1.1.529) variant in highly vaccinated populations has raised concerns about the effectiveness of current vaccines. Methods We used a test-negative case-control design to estimate vaccine effectiveness (VE) against symptomatic disease caused by the Omicron and Delta variants in En...
Preprint
Full-text available
Background The role of educational settings on SARS-CoV-2 infection and transmission remains controversial. We investigated SARS-CoV-2 infection, seroprevalence and seroconversions rates in secondary schools during the 2020/21 academic year, which included the emergence of the more transmissible Alpha and Delta variants, in England. Methods The UK...
Preprint
Full-text available
Background Reinfection after primary SARS-CoV-2 infection is uncommon in adults, but little is known about the risks, characteristics, severity or outcomes of reinfection in children. Methods We used national SARS-CoV-2 testing data in England to estimate the risk of reinfection ≥90 days after primary infection from 01 January 2020 to 31 July 2021...
Preprint
Full-text available
Adolescents in the UK were recommended to have their first dose of mRNA vaccine during a period of high community transmission due to the highly transmissible Delta variant, followed by a second dose at an extended interval of 8-12 weeks. We used national SARS-CoV-2 testing, vaccination and hospitalisation data to estimate vaccine effectiveness (VE...
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Full-text available
The UK prioritised delivery of the first dose of BNT162b2 (Pfizer/BioNTech) and AZD1222 (AstraZeneca) vaccines by extending the interval between doses up to 12 weeks. In 750 participants aged 50–89 years, we here compare serological responses after BNT162b2 and AZD1222 vaccination with varying dose intervals, and evaluate these against real-world n...
Preprint
UNSTRUCTURED One of the most debated questions in the COVID-19 pandemic has been the role of schools in SARS-CoV-2 transmission. The COVID-19 Schools Infection Survey (SIS) aims to provide much-needed evidence addressing this, and to investigate how transmission within, and from, schools could be mitigated through implementation of school COVID-19...
Article
Background: One of the most debated questions in the COVID-19 pandemic has been the role of schools in SARS-CoV-2 transmission. The COVID-19 Schools Infection Survey (SIS) aims to provide much-needed evidence addressing this. Objective: This paper presents the study protocol and participation profile for the SIS study, aimed at assessing the rol...
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Full-text available
Background Understanding the duration of protection and risk of reinfection after natural infection is crucial to planning COVID-19 vaccination for at-risk groups, including care home residents, particularly with the emergence of more transmissible variants. We report on the duration, neutralising activity, and protection against the alpha variant...
Article
Background In August, 2015, the UK implemented an emergency adolescent immunisation programme with the meningococcal ACWY conjugate vaccine to combat a national outbreak of meningococcal group W (MenW) disease due to a hypervirulent ST-11 complex strain, which is currently causing regional and national outbreaks worldwide. This immunisation program...
Article
Full-text available
Background The role of children and young people (CYP) in transmission of SARS-CoV-2 in household and educational settings remains unclear. We undertook a systematic review and meta-analysis of contact-tracing and population-based studies at low risk of bias. Methods We searched 4 electronic databases on 28 July 2021 for contact-tracing studies and...
Article
Memory B cells (MBC) can provide a recall response able to supplement waning antibodies with an affinity-matured response better able to neutralise variant viruses. We studied a cohort of elderly care home residents and younger staff (median age 87yrs and 56yrs respectively) who had survived COVID-19 outbreaks with only mild/asymptomatic infection....
Article
Background Most children recover quickly after COVID-19, but some may have on-going symptoms. Follow-up studies have been limited by small sample sizes and lack of appropriate controls Methods We used national testing data to identify children aged 2-16 years with a SARS-CoV-2 PCR test during 01-07 January 2021 and randomly selected1,500 PCR-posit...
Preprint
Full-text available
Importance: There are limited data on immune responses after COVID-19 vaccine boosters in individuals receiving primary immunisation with BNT162b2 (Pfizer-BioNTech) or AZD1222 (AstraZeneca) Objective: To assess SARS-CoV-2 antibody responses before and after booster vaccination with BNT162b2 in adults receiving two BNT162b2 or AZD1222 vaccine doses...
Preprint
Full-text available
We present a comprehensive analysis of antibody and cellular responses in children aged 12-16 years who received COVID-19 vaccination with ChAdOx1 (n=6) or mRNA vaccine (mRNA-1273 or BNT162b2, n=9) using a 12-week extended-interval schedule. mRNA vaccination of seropositive children induces high antibody levels, with one dose, but a second dose is...
Article
Full-text available
TIPiCO is an annual expert meeting and workshop on infectious diseases and vaccination. The edition of 2020 changed its name and format to aTIPiCO, the first series and podcasts on infectious diseases and vaccines. A total of 13 prestigious experts from different countries participated in this edition launched on the 26 November 2020. The state of...
Article
The benefits of in-person schooling with mitigations in place outweigh the risks of COVID-19 for children.
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Full-text available
Background Prospective, longitudinal SARS-CoV-2 sero-surveillance in schools across England was initiated after the first national lockdown, allowing comparison of child and adult antibody responses over time. Methods Prospective active serological surveillance in 46 primary schools in England tested for SARS-CoV-2 antibodies during June, July and...
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Full-text available
Background Data on the long-term impact of SARS-CoV-2 infection in children and young people (CYP) is conflicting. We assessed evidence on long-term post-COVID symptoms in CYP examining prevalence, risk factors, type and duration. Methods: Systematic search of published and unpublished literature using 13 online databases between 01/12/2019 – 31/07...
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Objectives In 2015 the UK became the first country to implement the meningococcal B (MenB) vaccine, 4CMenB, into the national infant programme. 4CMenB is expected to cover meningococci expressing sufficient levels of cross-reactive proteins. This study presents clonal complex, 4CMenB antigen genotyping, and 4CMenB coverage data for all English inva...
Preprint
Serological surveillance studies sometimes use presence of anti-nucleocapsid antibody as a marker of natural SARS-CoV-2 infection. We explore seroconversion rates and antibody titres following Alpha and Delta variant infections, and vaccine breakthrough infections. We find lower seroconversion rates particularly following Alpha-variant vaccine brea...
Article
Background: Universal mass vaccination (UMV) against rotavirus has been implemented in many but not all European countries. This study investigated the impact of UMV on rotavirus incidence trends by comparing European countries with UMV: Belgium, England/Wales and Germany versus countries without UMV: Denmark and the Netherlands. Methods: For th...
Preprint
Full-text available
Background COVID-19 vaccines have been used for 9 months in the UK. Real world data have demonstrated the vaccines to be highly effective against COVID-19, severe disease and death. Here, we estimate vaccine effectiveness over time since the second dose of Comirnaty, Vaxzevria and Spikevax in England. Methods We used a test-negative case-control de...
Preprint
Full-text available
Background Children and young people (CYP) were less affected than adults in the first wave of SARS-CoV-2 in the UK. We test the hypothesis that clinical characteristics of hospitalized CYP with SARS-CoV-2 in the UK second wave would differ from the first due to the combined impact of the alpha variant, school reopening and relaxation of shielding....