Effects of BNT162b2 Messenger RNA Vaccine and ChAdOx1 Adenovirus Vector Vaccine on Deaths From COVID-19 in Adults Aged ≥70 Years.

We estimated the risk of death from coronavirus disease 2019 in vaccinated compared with unvaccinated patients. The risk of death was reduced 44% after 1 dose of the Pfizer-BioNTech BNT162b2 vaccine, 55% after 1 dose of the Oxford-Astrazeneca ChAdOx1 vaccine, and 69% after 2 doses of the BNT162b2 vaccine. This is above the protection provided against infection.

Mixture modelling of Bordetella pertussis serology samples to evaluate anti-pertussis toxin immunoglobulin G titre thresholds for positivity: England 2008-2022.

Introduction. Antibody testing for evidence of a recent Bordetella pertussis infection by estimating anti-pertussis toxin immunoglobulin G (anti-PT-IgG) titres by enzyme-linked immunosorbent assays is often recommended for those with a cough lasting more than 14 days. Interpreting results varies, with studies recommending different anti-PT-IgG titre thresholds for assigning positivity. In England, early work looking at antibody titre distributions for samples submitted from April 2010 to July 2012 found an optimal threshold of greater than 70 IU ml-1 for good sensitivity, specificity and positive predictive value.Aim. The aim of this study is to use the same mixture modelling technique to determine if the 70 IU ml-1 threshold remains appropriate when assessing data before, during and after the outbreak of pertussis in 2011-2012.Methods. We reviewed titres for all serology-tested samples in England between 1 July 2008 to 30 June 2022. IgG titres were used to calculate the positivity based on the current threshold of 70 IU ml-1, the median duration of cough for individuals who tested positive and, through mixture modelling, the sensitivity, specificity, positive and negative predictive values (PPV and NPV) of assay thresholds.Results. Positivity rates increased from 21.7 % prior to the outbreak to 30.3 % during the outbreak and dropped to 25.1 % post-outbreak; similar to estimates from the mixture model of 20.5, 33.3 and 28.7 %, respectively. Although the estimated sensitivity dropped during and after the outbreak when applying the 70 IU ml-1 threshold, the PPV remained high and therefore no change to this threshold is warranted.Conclusion. Mixture modelling is a useful tool to establish thresholds, but reassessment should also be done when there have been changes to prevalence and/or testing regimes to determine whether there have been any changes in sensitivity, specificity, PPV, and NPV and whether the threshold should be revised.

High attack rate in a large care home outbreak of SARS-CoV-2 BA.2.86, East of England, August 2023.

We investigated an outbreak of SARS-CoV-2 variant BA.2.86 in an East of England care home. We identified 45 infections (33 residents, 12 staff), among 38 residents and 66 staff. Twenty-nine of 43 PCR swabs were sequenced, all of which were variant BA.2.86. The attack rate among residents was 87%, 19 were symptomatic, and one was hospitalised. Twenty-four days after the outbreak started, no cases were still unwell. Among the 33 resident cases, 29 had been vaccinated 4 months earlier.

Pertussis immunisation strategies to optimise infant pertussis control: A narrative systematic review.

OBJECTIVE: Countries routinely offering acellular pertussis vaccine, where long-term protection is not sustained, have the challenge of selecting an optimal schedule to minimise disease among young infants. We conducted a narrative systematic review and synthesis of information to evaluate different pertussis immunisation strategies at controlling pertussis disease, hospitalisation, deaths, and vaccine effectiveness among young infants. METHODS: We conducted a review of the literature on studies about the primary, booster, and/or maternal vaccination series and synthesised findings narratively. Countries offering the first three doses of vaccine within six-months of life and a booster on or before the second year or life were defined as accelerated primary and booster schedules, respectively. Countries offering primary and booster doses later were defined as extended primary and booster schedules. All search results were screened, and articles reviewed and reconciled, by two authors. The Risk of Bias in Non-randomised Studies of Intervention tool was used to evaluate the risk of bias. FINDINGS: A total of 98 studies were included in the analyses and the following recurring themes were described: timing of vaccination, vaccine coverage, waning immunity/vaccine effectiveness, direct and indirect effectiveness, switching from an accelerated to extended schedule, impact of changes in testing. The risk of bias was generally low to moderate for most studies. CONCLUSION: Comparing schedules is challenging and there was insufficient evidence to that one schedule was superior to another. Countries must select a schedule that maintains high vaccine coverage and reduced the risk of delaying the delivery vaccines to protect infants.

Bias assessment of a test-negative design study of COVID-19 vaccine effectiveness used in national policymaking.

National test-negative-case-control (TNCC) studies are used to monitor COVID-19 vaccine effectiveness in the UK. A questionnaire was sent to participants from the first published TNCC COVID-19 vaccine effectiveness study conducted by the UK Health Security Agency, to assess for potential biases and changes in behaviour related to vaccination. The original study included symptomatic adults aged ≥70 years testing for COVID-19 between 08/12/2020 and 21/02/2021. A questionnaire was sent to cases and controls tested from 1-21 February 2021. In this study, 8648 individuals responded to the questionnaire (36.5% response). Using information from the questionnaire to produce a combined estimate that accounted for all potential biases decreased the original vaccine effectiveness estimate after two doses of BNT162b2 from 88% (95% CI: 79-94%) to 85% (95% CI: 68-94%). Self-reported behaviour demonstrated minimal evidence of riskier behaviour after vaccination. These findings offer reassurance to policy makers and clinicians making decisions based on COVID-19 vaccine effectiveness TNCC studies.

Re-evaluation of the risk of venous thromboembolism after COVID-19 vaccination using haematological criteria.

An elevated risk of venous thromboembolism (VTE) following a first dose of the ChAdOx1 adenovirus-vectored vaccine was found in a national epidemiological study in England using routine discharge diagnosis codes. Separately, the syndrome of vaccine-induced immune thrombotic thrombocytopenia (VITT) was identified using haematological criteria based on presence of thrombocytopenia, significantly elevated D-dimers and development of anti-PF4 antibodies. To re-evaluate risk estimates using haematological criteria, we obtained the haematology results for hospital admitted patients aged 18-64 years in 43 National Health Service trusts in England who were included in the national epidemiological study. Diagnoses were confirmed and haematological parameters obtained from local records without knowledge of vaccination status. The haematological parameters in patients admitted for a confirmed VTE following ChAdOx1 or BNT162b2 mRNA vaccination were then compared with those in a randomly selected 40% sample of unvaccinated patients with VTE. Overall, 12 (14%) of the 84 vaccinated cases had a diagnosis compatible with VITT, 11 after a first dose of ChAdOx1 and one after a first dose of BNT162b2. Thrombocytopenia (platelet count <150 × 109/L) occurred in 17 vaccinated (20%) and 4 (4%) of 108 unvaccinated patients, with all 6 cases of severe thrombocytopenia (<50 × 109/L) occurring within 42 days of a first dose of ChAdOx1. The attributable risk estimates for a cerebral venous thrombosis (CVT) or other VTE with thrombocytopenia after a first dose of ChAdOx1 vaccine were 2.82 and 9.62 per million doses respectively. However, elevated risks were also found after a first dose of ChAdOx1 for VTE without thrombocytopenia with relative incidences for CVT and other VTE of 2.67 (1.77-3.77) and 1.93 (1.57-2.35) respectively. While we identified a distinct population with features of VITT within 42 days of receiving ChAdOx1 vaccination, confirming current diagnostic criteria, we also found evidence of an increased risk of a VTE without thrombocytopenia after ChAdOx1 vaccine.

The impact of COVID-19 on residents of long-term care facilities with learning disabilities and/or autism.

Background: The COVID-19 pandemic has had disproportionate impact on vulnerable populations including those with learning disabilities. Assessing the incidence and risk of death in such settings can improve the prevention of COVID-19. We describe individuals who tested positive for SARS-CoV-2 while residing in care homes for learning disabilities and/or autism and investigate the risk of death compared with individuals living in their own homes. Methods: Surveillance records for COVID-19 infections in England from 02 February 2020 to 31 March 2022 were extracted. Data on property type, variant wave, vaccination, hospitalisation and death were derived through data linkage and enrichment. Care home residents with learning disabilities and/or autism and diagnosed with COVID-19 were identified and analysed, and logistic regression analyses compared the risk of death of individuals living in private residence. We assessed interaction parameters by post-estimation analyses. Results: A total of 3501 individuals were identified as diagnosed with SARS-CoV-2 whilst living in 632 care home properties for learning disabilities and/or autism. Of the 3686 episodes of infection, 80.4% were part of an outbreak. The crude case fatality rate was 2.6% and 0.6% among care home residents with autism and/or learning disabilities and their counterparts in households, respectively.The post-estimation analyses found over eight times the odds of death among care home residents in 60 years old compared with their counterparts living in private homes. Conclusions: Care home residents with learning disabilities and/or autism have a greater risk of death from COVID-19. Optimising guidance to meet their needs is of great importance.

Comparative transmission of SARS-CoV-2 Omicron (B.1.1.529) and Delta (B.1.617.2) variants and the impact of vaccination: national cohort study, England.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant (B.1.1.529) rapidly replaced Delta (B.1.617.2) to become dominant in England. Our study assessed differences in transmission between Omicron and Delta using two independent data sources and methods. Omicron and Delta cases were identified through genomic sequencing, genotyping and S-gene target failure in England from 5-11 December 2021. Secondary attack rates for named contacts were calculated in household and non-household settings using contact tracing data, while household clustering was identified using national surveillance data. Logistic regression models were applied to control for factors associated with transmission for both methods. For contact tracing data, higher secondary attack rates for Omicron vs. Delta were identified in households (15.0% vs. 10.8%) and non-households (8.2% vs. 3.7%). For both variants, in household settings, onward transmission was reduced from cases and named contacts who had three doses of vaccine compared to two, but this effect was less pronounced for Omicron (adjusted risk ratio, aRR 0.78 and 0.88) than Delta (aRR 0.62 and 0.68). In non-household settings, a similar reduction was observed only in contacts who had three doses vs. two doses for both Delta (aRR 0.51) and Omicron (aRR 0.76). For national surveillance data, the risk of household clustering, was increased 3.5-fold for Omicron compared to Delta (aRR 3.54 (3.29-3.81)). Our study identified increased risk of onward transmission of Omicron, consistent with its successful global displacement of Delta. We identified a reduced effectiveness of vaccination in lowering risk of transmission, a likely contributor for the rapid propagation of Omicron.

Making the invisible visible: using national surveillance data to identify people experiencing homelessness in England with COVID-19.

Persons experiencing homelessness (PEH) or rough sleeping are a vulnerable population, likely to be disproportionately affected by the coronavirus disease 2019 (COVID-19) pandemic. The impact of COVID-19 infection on this population is yet to be fully described in England. We present a novel method to identify COVID-19 cases in this population and describe its findings. A phenotype was developed and validated to identify PEH or rough sleeping in a national surveillance system. Confirmed COVID-19 cases in England from March 2020 to March 2022 were address-matched to known homelessness accommodations and shelters. Further cases were identified using address-based indicators, such as NHS pseudo postcodes. In total, 1835 cases were identified by the phenotype. Most were <39 years of age (66.8%) and male (62.8%). The proportion of cases was highest in London (29.8%). The proportion of cases of a minority ethnic background and deaths were disproportionality greater in this population, compared to all COVID-19 cases in England. This methodology provides an approach to track the impact of COVID-19 on a subset of this population and will be relevant to policy making. Future surveillance systems and studies may benefit from this approach to further investigate the impact of COVID-19 and other diseases on select populations.

Monitoring the COVID-19 immunisation programme through a national immunisation Management system - England's experience.

BACKGROUND: In England routine vaccinations are recorded in either the patients General Practice record or in series of sub-national vaccine registers that are not interoperable. During the COVID-19 pandemic it was established that COVID vaccines would need to be delivered in multiple settings where current vaccine registers do not exist. We describe how a national vaccine register was created to collect data on COVID-19 vaccines. METHODS: The National Immunisation Management System (NIMS) was developed by a range of health and digital government agencies. Vaccinations delivered are entered on an application which is verified by individual National Health Service number in a centralised system. UKHSA receive a feed of this data to use for monitoring vaccine coverage, effectiveness, and safety. To validate the vaccination data, we compared vaccine records to self-reported vaccination dose, manufacturer, and vaccination date from the enhanced surveillance system from 11 February 2021 to 24 August 2021. RESULTS: With the Implementation of NIMS, we have been able to successfully record COVID-19 vaccinations delivered in multiple settings. Of 1,129 individuals, 97.8% were recorded in NIMS as unvaccinated compared to those who self-reported as unvaccinated. One hundred percent and 99.3% of individuals recorded in NIMS as having at least one dose and two doses of the COVID-19 vaccine were also self-reported as having at least one and two doses, respectively. Of the 100% reporting at least one dose, 98.3% self-reported the same vaccination date as NIMS. A total of 98.8% and 99.3% had the same manufacturer information for their first dose and second dose as that which was self-reported, respectively. DISCUSSION: Daily access to individual-level vaccine data from NIMS has allowed UKHSA to estimate vaccine coverage and provide some of the world's first vaccine effectiveness estimates rapidly and accurately.

Optimization of Timing of Maternal Pertussis Immunization From 6 Years of Postimplementation Surveillance Data in England.

BACKGROUND: England's third-trimester maternal pertussis vaccination, introduced in October 2012, was extended to the second trimester in 2016. Maternal vaccination provides high protection against infant disease, but routine second-trimester vaccination has not previously been assessed. METHODS: National laboratory-confirmed pertussis case surveillance determined vaccination history, maternal vaccination history and hospitalization. Pertussis hospital admissions between 2012 and 2019 were extracted from the Hospital Episode Statistics data set. Vaccine effectiveness (VE) was calculated for pertussis case patients born between October 2012 and September 2018 using the screening method and matching with a nationally representative data set. RESULTS: Higher coverage was observed after earlier maternal vaccination with approximately 40% of pregnant women vaccinated ≥13 weeks before delivery. Cases and hospitalizations stabilized at low levels in younger infants but remained elevated in older infants, children, and adults. No deaths occurred in infants with vaccinated mothers after 2016. Of 1162 laboratory-confirmed pertussis cases in the study, 599 (52%) were in infants aged <93 days: 463 (77%) with unvaccinated and 136 (23%) with vaccinated mothers. The VE was equivalent in infants with mothers vaccinated at different gestational periods except in those with mothers vaccinated between 7 days before and 41 days after delivery. Children whose mothers were unvaccinated but with vaccination in a previous pregnancy had a VE against disease of 44% (95% confidence interval, 19%-75%). There was no increased disease risk after primary vaccination in children with mothers vaccinated at least 7 days before delivery. CONCLUSIONS: National policy recommending vaccination in the second trimester increased earlier maternal vaccine uptake with sustained high VE and impact against early infant disease.

Equity of the Meningitis B vaccination programme in England, 2016-2018.

In England, the Meningitis B (MenB) vaccine is scheduled at eight and 16 weeks with a booster dose at one year of age and protects children against invasive bacterial meningococcal disease caused by Neisseria meningitidis serogroup B. Coverage of the second dose of MenB vaccine at 12 months was >92% in 2017/18, but this may mask inequalities in coverage in particular population groups. MenB vaccination records for children aged six, 12 and 18 months of age from December 2016 to May 2018 were routinely extracted from GP patient management systems every month in England via a web-based platform for national monitoring of vaccine coverage. We determined the association between ethnicity, deprivation and area of residence, vaccine coverage and drop-out rates (between dose one and dose two), using binomial regression. After adjusting for other factors, ethnic groups with lowest dose one coverage (Black or Black British-Caribbean, White-Any other White background, White-Irish) also had lowest dose two coverage, but in addition, these ethnic groups also had the largest drop-out rates between dose one and dose two. The drop-out rate for Black or Black British-Caribbean children was 5.7 percentage points higher than for White-British children. Vaccine coverage decreased with increasing deprivation quintile, and this was most marked for the booster coverage (6.2 percentage points lower in the most deprived compared to least deprived quintile, p < 0.001). To achieve high coverage for completed courses across all ethnic groups and deprivation quintiles both high initiation rates and a reduction in drop-out rates for ethnic groups with lowest coverage is necessary. A qualitative approach to better understand reasons behind lower coverage and higher drop-out rates in the most underserved ethnic groups is required to develop tailored approaches addressing these inequalities.

Long-Term Health-Related Quality of Life in Non-Hospitalized Coronavirus Disease 2019 (COVID-19) Cases With Confirmed Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Infection in England: Longitudinal Analysis and Cross-Sectional Comparison With Controls.

BACKGROUND: We aimed to quantify the unknown losses in health-related quality of life of coronavirus disease 2019 (COVID-19) cases using quality-adjusted lifedays (QALDs) and the recommended EQ-5D instrument in England. METHODS: Prospective cohort study of nonhospitalized, polymerase chain reaction (PCR)-confirmed severe acute respiratory syndrome coronavirus 2-positive (SARS-CoV-2-positive) cases aged 12-85 years and followed up for 6 months from 1 December 2020, with cross-sectional comparison to SARS-CoV-2-negative controls. Main outcomes were QALD losses; physical symptoms; and COVID-19-related private expenditures. We analyzed results using multivariable regressions with post hoc weighting by age and sex, and conditional logistic regressions for the association of each symptom and EQ-5D limitation on cases and controls. RESULTS: Of 548 cases (mean age 41.1 years; 61.5% female), 16.8% reported physical symptoms at month 6 (most frequently extreme tiredness, headache, loss of taste and/or smell, and shortness of breath). Cases reported more limitations with doing usual activities than controls. Almost half of cases spent a mean of £18.1 on nonprescription drugs (median: £10.0), and 52.7% missed work or school for a mean of 12 days (median: 10). On average, all cases lost 13.7 (95% confidence interval [CI]: 9.7, 17.7) QALDs, whereas those reporting symptoms at month 6 lost 32.9 (95% CI: 24.5, 37.6) QALDs. Losses also increased with older age. Cumulatively, the health loss from morbidity contributes at least 18% of the total COVID-19-related disease burden in the England. CONCLUSIONS: One in 6 cases report ongoing symptoms at 6 months, and 10% report prolonged loss of function compared to pre-COVID-19 baselines. A marked health burden was observed among older COVID-19 cases and those with persistent physical symptoms.

Characteristics associated with COVID-19 vaccine uptake among adults aged 50 years and above in England (8 December 2020-17 May 2021): a population-level observational study.

OBJECTIVE: To determine characteristics associated with COVID-19 vaccine coverage among individuals aged 50 years and above in England since the beginning of the programme. DESIGN: Observational cross-sectional study assessed by logistic regression and mean prevalence margins. SETTING: COVID-19 vaccinations delivered in England from 8 December 2020 to 17 May 2021. PARTICIPANTS: 30 624 257/61 967 781 (49.4%) and 17 360 045/61 967 781 (28.1%) individuals in England were recorded as vaccinated in the National Immunisation Management System with a first dose and a second dose of a COVID-19 vaccine, respectively. INTERVENTIONS: Vaccination status with COVID-19 vaccinations. MAIN OUTCOME MEASURES: Proportion, adjusted ORs and mean prevalence margins for individuals not vaccinated with dose 1 among those aged 50-69 years and dose 1 and 2 among those aged 70 years and above. RESULTS: Of individuals aged 50 years and above, black/African/Caribbean ethnic group was the least likely of all ethnic groups to be vaccinated with dose 1 of the COVID-19 vaccine. However, of those aged 70 years and above, the odds of not having dose 2 was 5.53 (95% CI 5.42 to 5.63) and 5.36 (95% CI 5.29 to 5.43) greater among Pakistani and black/African/Caribbean compared with white British ethnicity, respectively. The odds of not receiving dose 2 was 1.18 (95% CI 1.16 to 1.20) higher among individuals who lived in a care home compared with those who did not. This was the opposite to that observed for dose 1, where the odds of being unvaccinated was significantly higher among those not living in a care home (0.89 (95% CI 0.87 to 0.91)). CONCLUSIONS: We found that there are characteristics associated with low COVID-19 vaccine coverage. Inequalities, such as ethnicity are a major contributor to suboptimal coverage and tailored interventions are required to improve coverage and protect the population from SARS-CoV-2.

Uptake of infant and preschool immunisations in Scotland and England during the COVID-19 pandemic: An observational study of routinely collected data.

BACKGROUND: In 2020, the SARS-CoV-2 (COVID-19) pandemic and lockdown control measures threatened to disrupt routine childhood immunisation programmes with early reports suggesting uptake would fall. In response, public health bodies in Scotland and England collected national data for childhood immunisations on a weekly or monthly basis to allow for rapid analysis of trends. The aim of this study was to use these data to assess the impact of different phases of the pandemic on infant and preschool immunisation uptake rates. METHODS AND FINDINGS: We conducted an observational study using routinely collected data for the year prior to the pandemic (2019) and immediately before (22 January to March 2020), during (23 March to 26 July), and after (27 July to 4 October) the first UK "lockdown". Data were obtained for Scotland from the Public Health Scotland "COVID19 wider impacts on the health care system" dashboard and for England from ImmForm. Five vaccinations delivered at different ages were evaluated; 3 doses of "6-in-1" diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type b, and hepatitis B vaccine (DTaP/IPV/Hib/HepB) and 2 doses of measles, mumps, and rubella (MMR) vaccine. This represented 439,754 invitations to be vaccinated in Scotland and 4.1 million for England. Uptake during the 2020 periods was compared to the previous year (2019) using binary logistic regression analysis. For Scotland, uptake within 4 weeks of a child becoming eligible by age was analysed along with geographical region and indices of deprivation. For Scotland and England, we assessed whether immunisations were up-to-date at approximately 6 months (all doses 6-in-1) and 16 to 18 months (first MMR) of age. We found that uptake within 4 weeks of eligibility in Scotland for all the 5 vaccines was higher during lockdown than in 2019. Differences ranged from 1.3% for first dose 6-in-1 vaccine (95.3 versus 94%, odds ratio [OR] compared to 2019 1.28, 95% confidence intervals [CIs] 1.18 to 1.39) to 14.3% for second MMR dose (66.1 versus 51.8%, OR compared to 2019 1.8, 95% CI 1.74 to 1.87). Significant increases in uptake were seen across all deprivation levels. In England, fewer children due to receive their immunisations during the lockdown period were up to date at 6 months (6-in-1) or 18 months (first dose MMR). The fall in percentage uptake ranged from 0.5% for first 6-in-1 (95.8 versus 96.3%, OR compared to 2019 0.89, 95% CI 0.86- to 0.91) to 2.1% for third 6-in-1 (86.6 versus 88.7%, OR compared to 2019 0.82, 95% CI 0.81 to 0.83). The use of routinely collected data used in this study was a limiting factor as detailed information on potential confounding factors were not available and we were unable to eliminate the possibility of seasonal trends in immunisation uptake. CONCLUSIONS: In this study, we observed that the national lockdown in Scotland was associated with an increase in timely childhood immunisation uptake; however, in England, uptake fell slightly. Reasons for the improved uptake in Scotland may include active measures taken to promote immunisation at local and national levels during this period and should be explored further. Promoting immunisation uptake and addressing potential vaccine hesitancy is particularly important given the ongoing pandemic and COVID-19 vaccination campaigns.

Impact of the COVID-19 pandemic on Bordetella pertussis infections in England.

BACKGROUND: In March 2020, England went into its first lockdown in response to the COVID-19 pandemic. Restrictions eased temporarily, followed by second and third waves in October 2020 and January 2021. Recent data showed that the COVID-19 pandemic resulted in reduced transmission of some invasive diseases. We assess the impact of the COVID-19 pandemic on pertussis incidence and on the immunisation programme in England. METHODS: We assessed trends in pertussis cases from 2012 to 2020 by age group and month. Incidence from the time that England eased its initial lockdown measures in July 2020 through to summer 2021 was calculated and the incidence rate ratios of pertussis cases from five years prior to the pandemic (July 2014 - June 2019) compared to the same time period during the pandemic (July 2020 - June 2021). Vaccine coverage estimates for pertussis containing vaccines were reviewed for the maternal and childhood programmes. RESULTS: A substantial decline in pertussis cases was observed from April 2020 onwards, marking the lowest number of cases in the last decade. Pertussis incidence dropped in all age groups, particularly among infants less than one year old (0.50 / 100,000 during July 2020 to June 2021 compared to 24.49/ 100,000 from July 2014 to June 2019). The incidence rate ratio was 0.02 (95% CI 0.01 to 0.02) for July 2014 to June 2019 (pre-pandemic) compared to the pandemic period of July 2020 to June 2021. None of the cases had a co-infection with SARS-CoV-2. Vaccine coverage for infants born between January to March 2020 with three doses of pertussis vaccine by 12 months of age decreased by 1.1% points compared to infants born between January to March 2019 (91.6% and 92.7%, respectively). Prenatal pertussis coverage for the 2020 to 2021 financial year was 2.7% points lower than the year prior to the pandemic (70.5% and 76.8%, respectively). CONCLUSIONS: Lockdown measures due to the COVID-19 pandemic have had a significant impact on pertussis transmission. With the easing of restrictions it is important to continue monitoring pertussis cases in England alongside coverage of the maternal and childhood immunisation programmes.

Duration of Protection against Mild and Severe Disease by Covid-19 Vaccines.

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 wane over time since the receipt of the second dose of the ChAdOx1-S (ChAdOx1 nCoV-19) and BNT162b2 vaccines. METHODS: We used a test-negative case-control design to estimate vaccine effectiveness against symptomatic Covid-19 and related hospitalization and death in England. Effectiveness of the ChAdOx1-S and BNT162b2 vaccines was assessed according to participant age and status with regard to coexisting conditions and over time since receipt of the second vaccine dose to investigate waning of effectiveness separately for the B.1.1.7 (alpha) and B.1.617.2 (delta) variants. RESULTS: Vaccine effectiveness against symptomatic Covid-19 with the delta variant peaked in the early weeks after receipt of the second dose and then decreased by 20 weeks to 44.3% (95% confidence interval [CI], 43.2 to 45.4) with the ChAdOx1-S vaccine and to 66.3% (95% CI, 65.7 to 66.9) with the BNT162b2 vaccine. Waning of vaccine effectiveness was greater in persons 65 years of age or older than in those 40 to 64 years of age. At 20 weeks or more after vaccination, vaccine effectiveness decreased less against both hospitalization, to 80.0% (95% CI, 76.8 to 82.7) with the ChAdOx1-S vaccine and 91.7% (95% CI, 90.2 to 93.0) with the BNT162b2 vaccine, and death, to 84.8% (95% CI, 76.2 to 90.3) and 91.9% (95% CI, 88.5 to 94.3), respectively. Greater waning in vaccine effectiveness against hospitalization was observed in persons 65 years of age or older in a clinically extremely vulnerable group and in persons 40 to 64 years of age with underlying medical conditions than in healthy adults. CONCLUSIONS: We observed limited waning in vaccine effectiveness against Covid-19-related hospitalization and death at 20 weeks or more after vaccination with two doses of the ChAdOx1-S or BNT162b2 vaccine. Waning was greater in older adults and in those in a clinical risk group.