Effectiveness of Omicron XBB.1.5 vaccine against infection with SARS-CoV-2 Omicron XBB and JN.1 variants, prospective cohort study, the Netherlands, October 2023 to January 2024.

We estimated vaccine effectiveness (VE) of SARS-CoV-2 Omicron XBB.1.5 vaccination against self-reported infection between 9 October 2023 and 9 January 2024 in 23,895 XBB.1.5 vaccine-eligible adults who had previously received at least one booster. VE was 41% (95% CI: 23-55) in 18-59-year-olds and 50% (95% CI: 44-56) in 60-85-year-olds. Sequencing data suggest lower protection against the BA.2.86 (including JN.1) variant from recent prior infection (OR = 2.8; 95% CI:1.2-6.5) and, not statistically significant, from XBB.1.5 vaccination (OR = 1.5; 95% CI:0.8-2.6).

Health-related quality of life during the COVID-19 pandemic: The impact of restrictive measures using data from two Dutch population-based cohort studies.

OBJECTIVES: We describe health-related quality of life during the COVID-19 pandemic in the general Dutch population and correlations with restrictive measures. METHODS: Data were obtained from 18-85 year-old participants of two population-based cohort studies (February 2021-July 2022): PIENTER Corona (n = 8,019) and VASCO (n = 45,413). Per cohort, mean scores of mental and physical health and health utility from the SF-12 were calculated by age group, sex and presence of a medical risk condition. Spearman correlations with stringency of measures were calculated. RESULTS: Both cohorts showed comparable results. Participants <30 years had lowest health utility and mental health score, and highest physical health score. Health utility and mental health score increased with age (up to 79 years), while physical health score decreased with age. Women and participants with a medical risk condition scored lower than their counterparts. Fluctuations were small over time but most pronounced among participants <60 years, and correlated weakly, but mostly positively with measure stringency. CONCLUSIONS: During the Dutch COVID-19 epidemic, health utility and mental health scores were lower and fluctuated strongest among young adults compared to older adults. In our study population, age, sex and presence of a medical risk condition seemed to have more impact on health scores than stringency of COVID-19 non-pharmaceutical interventions.

Higher-valency pneumococcal conjugate vaccines in older adults, taking into account indirect effects from childhood vaccination: a cost-effectiveness study for the Netherlands.

BACKGROUND: New 15- and 20-valent pneumococcal vaccines (PCV15, PCV20) are available for both children and adults, while PCV21 for adults is in development. However, their cost-effectiveness for older adults, taking into account indirect protection and serotype replacement from a switch to PCV15 and PCV20 in childhood vaccination, remains unexamined. METHODS: We used a static model for the Netherlands to assess the cost-effectiveness of different strategies with 23-valent pneumococcal polysaccharide vaccine (PPV23), PCV15, PCV20, and PCV21 for a 65-year-old cohort from a societal perspective, over a 15-year time horizon. Childhood vaccination was varied from PCV10 to PCV13, PCV15, and PCV20. Indirect protection was assumed to reduce the incidence of vaccine serotypes in older adults by 80% (except for serotype 3, no effect), completely offset by an increase in non-vaccine serotype incidence due to serotype replacement. RESULTS: Indirect effects from childhood vaccination reduced the cost-effectiveness of vaccination of older adults, depending on the serotype overlap between the vaccines. With PCV10, PCV13, or PCV15 in children, PCV20 was more effective and less costly for older adults than PPV23 and PCV15. PCV20 costs approximately €10,000 per quality-adjusted life year (QALY) gained compared to no pneumococcal vaccination, which falls below the conventional Dutch €20,000/QALY gained threshold. However, with PCV20 in children, PCV20 was no longer considered cost-effective for older adults, costing €22,550/QALY gained. As indirect effects progressed over time, the cost-effectiveness of PCV20 for older adults further diminished for newly vaccinated cohorts. PPV23 was more cost-effective than PCV20 for cohorts vaccinated 3 years after the switch to PCV20 in children. PCV21 offered the most QALY gains, and its cost-effectiveness was minimally affected by indirect effects due to its coverage of 11 different serotypes compared to PCV20. CONCLUSIONS: For long-term cost-effectiveness in the Netherlands, the pneumococcal vaccine for older adults should either include invasive serotypes not covered by childhood vaccination or become more affordable than its current pricing for individual use.

Early COVID-19 vaccine effectiveness of XBB.1.5 vaccine against hospitalisation and admission to intensive care, the Netherlands, 9 October to 5 December 2023.

We present early vaccine effectiveness (VE) estimates of the 2023 seasonal COVID-19 XBB.1.5 vaccine against COVID-19 hospitalisation and admission to an intensive care unit (ICU) in previously vaccinated adults ≥ 60 years in the Netherlands. We compared vaccination status of 2,050 hospitalisations including 92 ICU admissions with age group-, sex-, region- and date-specific population vaccination coverage between 9 October and 5 December 2023. VE against hospitalisation was 70.7% (95% CI: 66.6-74.3), VE against ICU admission was 73.3% (95% CI: 42.2-87.6).

Effectiveness of Immunization Products Against Medically Attended Respiratory Syncytial Virus Infection: Generic Protocol for a Test-Negative Case-Control Study.

Monitoring the real-life effectiveness of respiratory syncytial virus (RSV) products is of major public health importance. This generic protocol for a test-negative design study aims to address currently envisioned approaches for RSV prevention (monoclonal antibodies and vaccines) to study effectiveness of these products among target groups: children, older adults, and pregnant women. The generic protocol approach was chosen to allow for flexibility in adapting the protocol to a specific setting. This protocol includes severe acute respiratory infection (SARI) and acute respiratory infection (ARI), both due to RSV, as end points. These end points can be applied to studies in hospitals, primarily targeting patients with more severe disease, but also to studies in general practitioner clinics targeting ARI.

Vaccine effectiveness against COVID-19 hospitalisation in adults (≥ 20 years) during Alpha- and Delta-dominant circulation: I-MOVE-COVID-19 and VEBIS SARI VE networks, Europe, 2021.

IntroductionTwo large multicentre European hospital networks have estimated vaccine effectiveness (VE) against COVID-19 since 2021.AimWe aimed to measure VE against PCR-confirmed SARS-CoV-2 in hospitalised severe acute respiratory illness (SARI) patients ≥ 20 years, combining data from these networks during Alpha (March-June)- and Delta (June-December)-dominant periods, 2021.MethodsForty-six participating hospitals across 14 countries follow a similar generic protocol using the test-negative case-control design. We defined complete primary series vaccination (PSV) as two doses of a two-dose or one of a single-dose vaccine ≥ 14 days before onset.ResultsWe included 1,087 cases (538 controls) and 1,669 cases (1,442 controls) in the Alpha- and Delta-dominant periods, respectively. During the Alpha period, VE against hospitalisation with SARS-CoV2 for complete Comirnaty PSV was 85% (95% CI: 69-92) overall and 75% (95% CI: 42-90) in those aged ≥ 80 years. During the Delta period, among SARI patients ≥ 20 years with symptom onset ≥ 150 days from last PSV dose, VE for complete Comirnaty PSV was 54% (95% CI: 18-74). Among those receiving Comirnaty PSV and mRNA booster (any product) ≥ 150 days after last PSV dose, VE was 91% (95% CI: 57-98). In time-since-vaccination analysis, complete all-product PSV VE was > 90% in those with their last dose < 90 days before onset; ≥ 70% in those 90-179 days before onset.ConclusionsOur results from this EU multi-country hospital setting showed that VE for complete PSV alone was higher in the Alpha- than the Delta-dominant period, and addition of a first booster dose during the latter period increased VE to over 90%.

Vaccine effectiveness against COVID-19 hospitalisation in adults (≥ 20 years) during Omicron-dominant circulation: I-MOVE-COVID-19 and VEBIS SARI VE networks, Europe, 2021 to 2022.

IntroductionThe I-MOVE-COVID-19 and VEBIS hospital networks have been measuring COVID-19 vaccine effectiveness (VE) in participating European countries since early 2021.AimWe aimed to measure VE against PCR-confirmed SARS-CoV-2 in patients ≥ 20 years hospitalised with severe acute respiratory infection (SARI) from December 2021 to July 2022 (Omicron-dominant period).MethodsIn both networks, 46 hospitals (13 countries) follow a similar test-negative case-control protocol. We defined complete primary series vaccination (PSV) and first booster dose vaccination as last dose of either vaccine received ≥ 14 days before symptom onset (stratifying first booster into received < 150 and ≥ 150 days after last PSV dose). We measured VE overall, by vaccine category/product, age group and time since first mRNA booster dose, adjusting by site as a fixed effect, and by swab date, age, sex, and presence/absence of at least one commonly collected chronic condition.ResultsWe included 2,779 cases and 2,362 controls. The VE of all vaccine products combined against hospitalisation for laboratory-confirmed SARS-CoV-2 was 43% (95% CI: 29-54) for complete PSV (with last dose received ≥ 150 days before onset), while it was 59% (95% CI: 51-66) after addition of one booster dose. The VE was 85% (95% CI: 78-89), 70% (95% CI: 61-77) and 36% (95% CI: 17-51) for those with onset 14-59 days, 60-119 days and 120-179 days after booster vaccination, respectively.ConclusionsOur results suggest that, during the Omicron period, observed VE against SARI hospitalisation improved with first mRNA booster dose, particularly for those having symptom onset < 120 days after first booster dose.

Assessment of hybrid population immunity to SARS-CoV-2 following breakthrough infections of distinct SARS-CoV-2 variants by the detection of antibodies to nucleoprotein.

Immunity induced by vaccination and infection, referred to as hybrid immunity, provides better protection against SARS-CoV-2 infections compared to immunity induced by vaccinations alone. To assess the development of hybrid immunity we investigated the induction of Nucleoprotein-specific antibodies in PCR-confirmed infections by Delta or Omicron in vaccinated individuals (n = 520). Eighty-two percent of the participants with a breakthrough infection reached N-seropositivity. N-seropositivity was accompanied by Spike S1 antibody boosting, and independent of vaccination status or virus variant. Following the infection relatively more antibodies to the infecting virus variant were detected. In conclusion, these data show that hybrid immunity through breakthrough infections is hallmarked by Nucleoprotein antibodies and broadening of the Spike antibody repertoire. Exposure to future SARS-CoV-2 variants may therefore continue to maintain and broaden vaccine-induced population immunity.

Effects of COVID-19 vaccination and previous infection on Omicron SARS-CoV-2 infection and relation with serology.

An increasing proportion of the population has acquired immunity through COVID-19 vaccination and previous SARS-CoV-2 infection, i.e., hybrid immunity, possibly affecting the risk of new infection. We aim to estimate the protective effect of previous infections and vaccinations on SARS-CoV-2 Omicron infection, using data from 43,257 adult participants in a prospective community-based cohort study in the Netherlands, collected between 10 January 2022 and 1 September 2022. Our results show that, for participants with 2, 3 or 4 prior immunizing events (vaccination or previous infection), hybrid immunity is more protective against infection with SARS-CoV-2 Omicron than vaccine-induced immunity, up to at least 30 weeks after the last immunizing event. Differences in risk of infection are partly explained by differences in anti-Spike RBD (S) antibody concentration, which is associated with risk of infection in a dose-response manner. Among participants with hybrid immunity, with one previous pre-Omicron infection, we do not observe a relevant difference in risk of Omicron infection by sequence of vaccination(s) and infection. Additional immunizing events increase the protection against infection, but not above the level of the first weeks after the previous event.

Effect of COVID-19 vaccination on mortality by COVID-19 and on mortality by other causes, the Netherlands, January 2021-January 2022.

BACKGROUND: We aimed to estimate vaccine effectiveness (VE) against COVID-19 mortality, and to explore whether an increased risk of non-COVID-19 mortality exists in the weeks following a COVID-19 vaccine dose. METHODS: National registries of causes of death, COVID-19 vaccination, specialized health care and long-term care reimbursements were linked by a unique person identifier using data from 1 January 2021 to 31 January 2022. We used Cox regression with calendar time as underlying time scale to, firstly, estimate VE against COVID-19 mortality after primary and first booster vaccination, per month since vaccination and, secondly, estimate risk of non-COVID-19 mortality in the 5 or 8 weeks following a first, second or first booster dose, adjusting for birth year, sex, medical risk group and country of origin. RESULTS: VE against COVID-19 mortality was > 90 % for all age groups two months after completion of the primary series. VE gradually decreased thereafter, to around 80 % at 7-8 months post-primary series for most groups, and around 60 % for elderly receiving a high level of long-term care and for people aged 90+ years. Following a first booster dose, the VE increased to > 85 % in all groups. The risk of non-COVID-19 mortality was lower or similar in the 5 or 8 weeks following a first dose compared to no vaccination, as well as following a second dose compared to one dose and a booster compared to two doses, for all age and long-term care groups. CONCLUSION: At the population level, COVID-19 vaccination greatly reduced the risk of COVID-19 mortality and no increased risk of death from other causes was observed.

Meningococcal ACWY conjugate vaccine immunogenicity and safety in adolescents with juvenile idiopathic arthritis and inflammatory bowel disease: A prospective observational cohort study.

BACKGROUND: Immunogenicity to meningococcal serogroup ACWY (MenACWY) conjugate vaccine has not been studied in immunocompromised minors with juvenile idiopathic arthritis (JIA) or inflammatory bowel disease (IBD). We determined immunogenicity of a MenACWY-TT vaccine in JIA and IBD patients at adolescent age and compared results to data from aged-matched healthy controls (HCs). METHODS: We performed a prospective observational cohort study in JIA and IBD patients (14-18 years old), who received a MenACWY vaccination during a nationwide catch-up campaign (2018-2019) in the Netherlands. Primary aim was to compare MenACWY polysaccharide-specific serum IgG geometric mean concentrations (GMCs) in patients with HCs and secondary between patients with or without anti-TNF therapy. GMCs were determined before and 3-6, 12, and 24 months postvaccination and compared with data from HCs at baseline and 12 months postvaccination. Serum bactericidal antibody (SBA) titers were determined in a subset of patients at 12 months postvaccination. RESULTS: We included 226 JIA and IBD patients (66 % and 34 % respectively). GMCs were lower for MenA and MenW (GMC ratio 0·24 [0·17-0·34] and 0·16 [0·10-0·26] respectively, p < 0·01) in patients compared to HCs at 12 months postvaccination. Anti-TNF users had lower MenACWY GMCs postvaccination compared with those without anti-TNF (p < 0·01). The proportion protected (SBA ≥ 8) for MenW was reduced in anti-TNF users (76 % versus 92 % in non-anti-TNF and 100 % in HCs, p < 0.01). CONCLUSION: The MenACWY conjugate vaccine was immunogenic in the vast majority of JIA and IBD patients at adolescent age, but seroprotection was lower in patients using anti-TNF agents. Therefore, an extra booster MenACWY vaccination should be considered.

Number of COVID-19 hospitalisations averted by vaccination: Estimates for the Netherlands, January 6, 2021 through August 30, 2022.

BACKGROUND: Vaccines against COVID-19 have proven effective in preventing COVID-19 hospitalisation. In this study, we aimed to quantify part of the public health impact of COVID-19 vaccination by estimating the number of averted hospitalisations. We present results from the beginning of the vaccination campaign ('entire period', January 6, 2021) and a subperiod starting at August 2, 2021 ('subperiod') when all adults had the opportunity to complete their primary series, both until August 30, 2022. METHODS: Using calendar-time specific vaccine effectiveness (VE) estimates and vaccine coverage (VC) by round (primary series, first booster and second booster) and the observed number of COVID-19 associated hospitalisations, we estimated the number of averted hospitalisations per age group for the two study periods. From January 25, 2022, when registration of the indication of hospitalisation started, hospitalisations not causally related to COVID-19 were excluded. RESULTS: In the entire period, an estimated 98,170 (95 % confidence interval (CI) 96,123-99,928) hospitalisations were averted, of which 90,753 (95 % CI 88,790-92,531) were in the subperiod, representing 57.0 % and 67.9 % of all estimated hospital admissions. Estimated averted hospitalisations were lowest for 12-49-year-olds and highest for 70-79-year-olds. More admissions were averted in the Delta period (72.3 %) than in the Omicron period (63.4 %). CONCLUSION: COVID-19 vaccination prevented a large number of hospitalisations. Although the counterfactual of having had no vaccinations while maintaining the same public health measures is unrealistic, these findings underline the public health importance of the vaccination campaign to policy makers and the public.

Vaccine effectiveness of primary and booster COVID-19 vaccinations against SARS-CoV-2 infection in the Netherlands from July 12, 2021 to June 6, 2022: A prospective cohort study.

OBJECTIVES: We estimated vaccine effectiveness (VE) of primary and booster vaccinations against SARS-CoV-2 infection overall and in four risk groups defined by age and medical risk condition during the Delta and Omicron BA.1/BA.2 periods. METHODS: VAccine Study COvid-19 is an ongoing prospective cohort study among Dutch adults. The primary end point was a self-reported positive SARS-CoV-2 test from July 12, 2021 to June 06, 2022. The analyses included only participants without a previous SARS-CoV-2 infection based on a positive test or serology. We used Cox proportional hazard models with vaccination status as the time-varying exposure and adjustment for age, sex, educational level, and medical risk condition. RESULTS: A total of 37,170 participants (mean age 57 years) were included. In the Delta period, VE <6 weeks after the primary vaccination was 80% (95% confidence interval 69-87) and decreased to 71% (65-77) after 6 months. VE increased to 96% (86-99) shortly after the first booster vaccination. In the Omicron period, these estimates were 46% (22-63), 25% (8-39), and 57% (52-62), respectively. For the Omicron period, an interaction term between vaccination status and risk group significantly improved the model (P <0.001), with generally lower VEs for those with a medical risk condition. CONCLUSION: Our results show the benefit of booster vaccinations against infection, also in risk groups; although, the additional protection wanes quite rapidly.

Vaccine Effectiveness Against Severe Acute Respiratory Syndrome Coronavirus 2 Delta and Omicron Infection and Infectiousness Within Households in the Netherlands Between July 2021 and August 2022.

BACKGROUND: We aimed to estimate vaccine effectiveness against infection (VE-infection) and against further transmission (VE-infectiousness) in a household setting during Delta and Omicron. Knowing these effects can aid policy makers in deciding which groups to prioritize for vaccination. METHODS: Participants with a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test were asked about coronavirus disease 2019 (COVID-19) vaccination status and SARS-CoV-2 testing of their household members 1 month later. VE-infection and VE-infectiousness were estimated using generalized estimating equation logistic regression adjusting for age, vaccination status, calendar week, and household size. RESULTS: A total of 3399 questionnaires concerning 4105 household members were included. During the Delta period, VE-infection and VE-infectiousness of primary series were 47% (95% confidence interval [CI], -27% to 78%) and 70% (95% CI, 28% to 87%), respectively. During the Omicron period, VE-infection was -36% (95% CI, -88% to 1%) for primary series and -28% (95% CI, -77% to 7%) for booster vaccination. VE-infectiousness was 45% (95% CI, -14% to 74%) for primary series and 64% (95% CI, 31% to 82%) for booster vaccination. CONCLUSIONS: Our study shows that COVID-19 vaccination is effective against infection with SARS-CoV-2 Delta and against infectiousness of SARS-CoV-2 Delta and Omicron. Estimation of VE against infection with SARS-CoV-2 Omicron was limited by several factors. Our results support booster vaccination for those in close contact with vulnerable people to prevent transmission.

The burden of invasive meningococcal disease in the Netherlands, 2011-2020.

INTRODUCTION: Representative information on disease course and outcome of invasive meningococcal disease (IMD) is important because of the shift in meningococcal epidemiology that recently occurred in the Netherlands. With this study, we update earlier research on the burden of IMD in the Netherlands. MATERIAL AND METHODS: We performed a retrospective study using Dutch surveillance data on IMD from July 2011 to May 2020. Clinical information was collected from hospital records. The effect of age, serogroup, and clinical manifestation on disease course and outcome was assessed in multivariable logistic regression analyses. Grouping of infecting isolates was performed by Ouchterlony gel diffusion or by PCR. RESULTS: Clinical information was collected for 278 IMD cases of which the majority had IMD-B (55%), followed by IMD-W (27%), IMD-Y (13%), and IMD-C (5%). Most patients presented with meningitis (32%) or sepsis (30%). Hospitalisation for ≥ 10 days was most frequent among 24-64 year olds (67%). ICU admission was highest among 24-64 year olds (60%), and in case of sepsis (70%), or sepsis plus meningitis (61%). Sequelae at discharge was lower for patients with mild meningococcaemia compared to patients with sepsis plus meningitis (OR: 0.19, 95% CI: 0.07-0.51). The overall case fatality rate was 7%, and was highest for IMD-Y (14%) and IMD-W (13%) patients. CONCLUSIONS: IMD remains a disease with high morbidity and mortality. Sepsis (with or without meningitis) is associated with a more severe disease course and outcome compared to other clinical manifestations. The high disease burden can be partly prevented by meningococcal vaccination.

Higher risk of SARS-CoV-2 Omicron BA.4/5 infection than of BA.2 infection after previous BA.1 infection, the Netherlands, 2 May to 24 July 2022.

BackgroundIn summer 2022, SARS-CoV-2 Omicron BA.5 became dominant in Europe. In vitro studies have shown a large reduction of antibody neutralisation for this variant.AimWe aimed to investigate differences in protection from previous infection and/or vaccination against infection with Omicron BA.4/5 vs BA.2.MethodsWe employed a case-only approach including positive PCR tests from community testing between 2 May and 24 July 2022 that were tested for S gene target failure (SGTF), which distinguishes BA.4/5 from BA.2 infection. Previous infections were categorised by variant using whole genome sequencing or SGTF. We estimated by logistic regression the association of SGTF with vaccination and/or previous infection, and of SGTF of the current infection with the variant of the previous infection, adjusting for testing week, age group and sex.ResultsThe percentage of registered previous SARS-CoV-2 infections was higher among 19,836 persons infected with Omicron BA.4/5 than among 7,052 persons infected with BA.2 (31.3% vs 20.0%). Adjusting for testing week, age group and sex, the adjusted odds ratio (aOR) was 1.4 (95% CI: 1.3-1.5). The distribution of vaccination status did not differ for BA.4/5 vs BA.2 infections (aOR = 1.1 for primary and booster vaccination). Among persons with a previous infection, those currently infected with BA4/5 had a shorter interval between infections, and the previous infection was more often caused by BA.1, compared with those currently infected with BA.2 (aOR = 1.9; 95% CI: 1.5-2.6).ConclusionOur results suggest immunity induced by BA.1 is less effective against BA.4/5 infection than against BA.2 infection.

Effectiveness of bivalent mRNA booster vaccination against SARS-CoV-2 Omicron infection, the Netherlands, September to December 2022.

We used data of 32,542 prospective cohort study participants who previously received primary and one or two monovalent booster COVID-19 vaccinations. Between 26 September and 19 December 2022, relative effectiveness of bivalent original/Omicron BA.1 vaccination against self-reported Omicron SARS-CoV-2 infection was 31% in 18-59-year-olds and 14% in 60-85-year-olds. Protection of Omicron infection was higher than of bivalent vaccination without prior infection. Although bivalent booster vaccination increases protection against COVID-19 hospitalisations, we found limited added benefit in preventing SARS-CoV-2 infection.

Elevated risk of infection with SARS-CoV-2 Beta, Gamma, and Delta variants compared with Alpha variant in vaccinated individuals.

The extent to which severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern (VOCs) break through infection- or vaccine-induced immunity is not well understood. We analyzed 28,578 sequenced SARS-CoV-2 samples from individuals with known immune status obtained through national community testing in the Netherlands from March to August 2021. We found evidence of an increased risk of infection by the Beta (B.1.351), Gamma (P.1), or Delta (B.1.617.2) variants compared with the Alpha (B.1.1.7) variant after vaccination. No clear differences were found between vaccines. However, the effect was larger in the first 14 to 59 days after complete vaccination compared with ≥60 days. In contrast to vaccine-induced immunity, there was no increased risk for reinfection with Beta, Gamma, or Delta variants relative to the Alpha variant in individuals with infection-induced immunity.

COVID-19 vaccine effectiveness against SARS-CoV-2 infection during the Delta period, a nationwide study adjusting for chance of exposure, the Netherlands, July to December 2021.

BackgroundDifferential SARS-CoV-2 exposure between vaccinated and unvaccinated individuals may confound vaccine effectiveness (VE) estimates.AimWe conducted a test-negative case-control study to determine VE against SARS-CoV-2 infection and the presence of confounding by SARS-CoV-2 exposure.MethodsWe included adults tested for SARS-CoV-2 at community facilities between 4 July and 8 December 2021 (circulation period of the Delta variant). The VE against SARS-CoV-2 infection after primary vaccination with an mRNA (Comirnaty or Spikevax) or vector-based vaccine (Vaxzevria or Janssen) was calculated using logistic regression adjusting for age, sex and calendar week (Model 1). We additionally adjusted for comorbidity and education level (Model 2) and SARS-CoV-2 exposure (number of close contacts, visiting busy locations, household size, face mask wearing, contact with SARS-CoV-2 case; Model 3). We stratified by age, vaccine type and time since vaccination.ResultsVE against infection (Model 3) was 64% (95% CI: 50-73), only slightly lower than in Models 1 (68%; 95% CI: 58-76) and 2 (67%; 95% CI: 56-75). Estimates stratified by age group, vaccine and time since vaccination remained similar: mRNA VE (Model 3) among people ≥ 50 years decreased significantly (p = 0.01) from 81% (95% CI: 66-91) at < 120 days to 61% (95% CI: 22-80) at ≥ 120 days after vaccination. It decreased from 83% to 59% in Model 1 and from 81% to 56% in Model 2.ConclusionSARS-CoV-2 exposure did not majorly confound the estimated COVID-19 VE against infection, suggesting that VE can be estimated accurately using routinely collected data without exposure information.