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In this population-based cohort of 7538 adults, combined immunoglobulin (Ig) G, IgA, and IgM (IgG/A/M) anti-spike titers measured after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination were predictive of protection against breakthrough SARS-CoV-2 infection. Discrimination was significantly improved by adjustment for factors influencing risk of SARS-CoV-2 exposure, including household overcrowding, public transport use, and visits to indoor public places. Anti-spike IgG/A/M titers showed positive correlation with neutralizing antibody titers (rs = 0.80 [95% confidence interval, .72–.86]; P < .001) and S peptide–stimulated interferon-γ concentrations (rs = 0.31 [.13–.47]; P < .001).

ObjectiveTo determine the effect of population level implementation of a test-and-treat approach to correction of suboptimal vitamin D status (25-hydroxyvitamin D (25(OH)D) DesignPhase 3 open label randomised controlled trial.SettingUnited Kingdom.Participants6200 people aged ≥16 years who were not taking vitamin D supplements at baseline.InterventionsOffer of a postal finger prick test of blood 25(OH)D concentration with provision of a six month supply of lower dose vitamin D (800 IU/day, n=1550) or higher dose vitamin D (3200 IU/day, n=1550) to those with blood 25(OH)D concentration Main outcome measuresThe primary outcome was the proportion of participants with at least one swab test or doctor confirmed acute respiratory tract infection of any cause. A secondary outcome was the proportion of participants with swab test confirmed covid-19. Logistic regression was used to calculate odds ratios and associated 95% confidence intervals. The primary analysis was conducted by intention to treat.ResultsOf 3100 participants offered a vitamin D test, 2958 (95.4%) accepted and 2674 (86.3%) had 25(OH)D concentrations ConclusionsAmong people aged 16 years and older with a high baseline prevalence of suboptimal vitamin D status, implementation of a population level test-and-treat approach to vitamin D supplementation was not associated with a reduction in risk of all cause acute respiratory tract infection or covid-19.Trial registrationClinicalTrials.govNCT04579640.

Antibody responses to SARS-CoV-2 vaccines vary for reasons that remain poorly understood. A range of sociodemographic, behavioural, clinical, pharmacologic and nutritional factors could explain these differences. To investigate this hypothesis, we tested for presence of combined IgG, IgA and IgM (IgGAM) anti-Spike antibodies before and after 2 doses of ChAdOx1 nCoV-19 (ChAdOx1, AstraZeneca) or BNT162b2 (Pfizer-BioNTech) in UK adults participating in a population-based longitudinal study who received their first dose of vaccine between December 2020 and July 2021. Information on sixty-six potential sociodemographic, behavioural, clinical, pharmacologic and nutritional determinants of serological response to vaccination was captured using serial online questionnaires. We used logistic regression to estimate multivariable-adjusted odds ratios (aORs) for associations between independent variables and risk of seronegativity following two vaccine doses. Additionally, percentage differences in antibody titres between groups were estimated in the sub-set of participants who were seropositive post-vaccination using linear regression. Anti-spike antibodies were undetectable in 378/9101 (4.2%) participants at a median of 8.6 weeks post second vaccine dose. Increased risk of post-vaccination seronegativity associated with administration of ChAdOx1 vs. BNT162b2 (adjusted odds ratio (aOR) 6.6, 95% CI 4.2–10.4), shorter interval between vaccine doses (aOR 1.6, 1.2–2.1, 6–10 vs. >10 weeks), poor vs. excellent general health (aOR 3.1, 1.4–7.0), immunodeficiency (aOR 6.5, 2.5–16.6) and immunosuppressant use (aOR 3.7, 2.4–5.7). Odds of seronegativity were lower for participants who were SARS-CoV-2 seropositive pre-vaccination (aOR 0.2, 0.0–0.6) and for those taking vitamin D supplements (aOR 0.7, 0.5–0.9). Serologic responses to vaccination did not associate with time of day of vaccine administration, lifestyle factors including tobacco smoking, alcohol intake and sleep, or use of anti-pyretics for management of reactive symptoms after vaccination. In a sub-set of 8727 individuals who were seropositive post-vaccination, lower antibody titres associated with administration of ChAdOx1 vs. BNT162b2 (43.4% lower, 41.8–44.8), longer duration between second vaccine dose and sampling (12.7% lower, 8.2–16.9, for 9–16 weeks vs. 2–4 weeks), shorter interval between vaccine doses (10.4% lower, 3.7–16.7, for 10 weeks), receiving a second vaccine dose in October–December vs. April–June (47.7% lower, 11.4–69.1), older age (3.3% lower per 10-year increase in age, 2.1–4.6), and hypertension (4.1% lower, 1.1–6.9). Higher antibody titres associated with South Asian ethnicity (16.2% higher, 3.0–31.1, vs. White ethnicity) or Mixed/Multiple/Other ethnicity (11.8% higher, 2.9–21.6, vs. White ethnicity), higher body mass index (BMI; 2.9% higher, 0.2–5.7, for BMI 25–30 vs.

OBJECTIVESTo determine whether population-level implementation of a test-and- treat approach to correction of sub-optimal vitamin D status (25-hydroxyvitamin D [25(OH)D] DESIGNPhase 3 open-label randomised controlled trial (CORONAVIT) utilising trials-within-cohorts (TwiCs) methodology.SETTINGUnited Kingdom.PARTICIPANTS6200 adults aged 16 years or older, who were not already taking vitamin D supplements at baseline.INTERVENTIONSOffer of a postal finger-prick test of blood 25(OH)D concentration with provision of a 6-month supply of higher-dose vitamin D (3200 IU/day, n=1550) or lower-dose vitamin D (800 IU/day, n=1550) to those with blood 25(OH)D concentration th December 2020 to 16th June 2021.MAIN OUTCOME MEASURESThe primary outcome was the proportion of participants experiencing at least one doctor- or swab test-confirmed ARI of any cause. Secondary outcomes included the proportion of participants developing swab test-confirmed COVID-19. Logistic regression was used to calculate odds ratios and associated 95% confidence intervals.RESULTSOf 3100 participants offered 25(OH)D testing, 2958 (95.4%) accepted, and 2690 (86.8%) had 25(OH)D CONCLUSIONSAmong adults with a high baseline prevalence of sub-optimal vitamin D status, implementation of a population-level test-and-treat approach to vitamin D replacement did not reduce risk of all-cause ARI or COVID-19.TRIAL REGISTRATIONClinicalTrials.gov no. NCT04579640SUMMARY BOXWhat is already known on this topic?Vitamin D metabolites support innate immune responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other respiratory pathogens. Sub-optimal vitamin D status (25-hydroxyvitamin D What this study addsThis phase 3 randomised controlled trial, including 6200 participants, shows that implementation of a population-level test-and-treat approach to oral vitamin D replacement at a dose of 800 IU or 3200 IU per day did not reduce risk of all-cause ARI or COVID-19 among adults with a high baseline prevalence of sub-optimal vitamin D status.

In this population-based cohort of 7530 adults, combined IgG/A/M anti-Spike titres measured after SARS-CoV-2 vaccination were predictive of protection against breakthrough SARS-CoV-2 infection. Discrimination was significantly improved by adjustment for factors influencing risk of SARS-CoV-2 exposure including household overcrowding, public transport use, and visits to indoor public places.

SummaryBackgroundAntibody responses to SARS-CoV-2 vaccination vary for reasons that remain poorly understood.MethodsWe tested for presence of combined IgG, IgA and IgM (IgGAM) anti-spike antibodies before and after administration of two doses of ChAdOx1 nCoV-19 (ChAdOx1, Oxford-AstraZeneca) or BNT162b2 (Pfizer-BioNTech) in UK adults participating in a population-based longitudinal study who received their first dose of vaccine from December 15, 2020 to July 10, 2021. Information on sixty-six potential sociodemographic, behavioural, clinical, pharmacological and nutritional determinants of serological response to vaccination was captured using serial online questionnaires. We used logistic regression to estimate multivariable-adjusted odds ratios (aORs) for associations between independent variables and risk of seronegativity following two vaccine doses. Participants who were seronegative after receiving two vaccine doses were offered an additional antibody test following subsequent administration of a ‘booster’ dose of BNT162b2 or mRNA-1273 (Moderna) from September 23 to December 12, 2021.FindingsSerology results following two vaccine doses were available for 9,101 participants, of whom 5,770 (63.4%) received ChAdOx1 and 3,331 (36.6%) received BNT162b2. Anti-spike IgGAM was undetectable in 378 (4.2%) participants at a median of 8.6 weeks (IQR 6.4-10.7 weeks) after their second dose of vaccine. Seronegativity following two doses of SARS-CoV-2 vaccination was associated with administration of ChAdOx1 vs BNT162b2 (aOR 7.03, 95% CI 4.39-11.24), shorter interval between first and second vaccine doses (aOR 2.37, 1.06-5.26, for vs >10 weeks; aOR 1.59, 1.18-2.13, for 6-10 weeks vs >10 weeks), poorer self-assessed general health (aOR 3.33, 1.49-7.46, for poor vs excellent), immunodeficiencies (aOR 6.75, 2.63-17.35) and prescription of systemic immunosuppressants (aOR 3.76, 2.44-5.78). By contrast, pre-vaccination SARS-CoV-2 seropositivity (aOR 0.16, 0.04-0.70, for symptomatic seropositives vs seronegatives) and supplemental vitamin D intake (aOR 0.73, 0.53-0.99) were associated with reduced risk of post-vaccination seronegativity. 247/378 (65.3%) of participants who were seronegative after two doses of ChAdOx1 vs BNT162b2 provided a third sample at a median of 7.8 weeks (IQR 5.8-10.4) after receiving a booster dose of BNT162b2 or mRNA-1273: eight (3.2%) of them remained seronegative after three vaccine doses, all of whom either had a primary immunodeficiency or were taking systemic immunosuppressant drugs.InterpretationWe identify multiple determinants of antibody responses to two doses of ChAdOx1 or BNT162b2, many of which are potentially modifiable. Booster doses of BNT162b2 or mRNA-1273 were highly effective in achieving seroconversion in those who failed to mount antibody responses following two doses of ChAdOx1 or BNT162b2.Study registrationhttps://clinicaltrials.gov/ct2/show/NCT04330599FundingBarts Charity, Fischer Family Trust, The Exilarch’s Foundation, DSM Nutritional Products, Health Data Research UKResearch in contextEvidence before this studyWe searched PubMed, medRxiv, and Google Scholar for papers published from January 1, 2020, to February 1, 2022, using the search terms (antibody OR humoral OR serologic* OR immunogenic*) AND (SARS-CoV-2 vaccine OR ChAdOx1 or BNT162b2 coronavirus), with no language restrictions. Population-based studies investigating multiple potential determinants of vaccine immunogenicity in people with known pre-vaccination SARS-CoV-2 serostatus are lacking.Added value of this studyThis large population-based study, conducted in a population with known pre-vaccination SARS-CoV-2 serostatus, examines a comprehensive range of potential sociodemographic, behavioural, clinical, pharmacological and nutritional determinants of antibody responses to administration of two major SARS-CoV-2 vaccines (i.e., ChAdOx1 or BNT162b2), many of which have not previously been investigated. It is also the first population-based study to characterise antibody responses to booster doses of SARS-CoV-2 vaccines in adults who were seronegative after their primary course of vaccination.Implications of all the available evidenceIncreased risk of seronegativity following two doses of SARS-CoV-2 vaccines was associated with administration of ChAdOx1 vs BNT162b2, shorter interval between first and second vaccine doses, poorer self-assessed general health, immunocompromise and SARS-CoV-2 seronegativity pre-vaccination. Regular intake of vitamin D supplements was associated with reduced risk of post-vaccination seronegativity. Randomised controlled trials are now needed to test for causality. Booster doses of BNT162b2 or mRNA-1273 were highly effective in achieving seroconversion in the majority of people who failed to mount antibody responses following a primary course of vaccination, the few exceptions being a subset of those with primary immunodeficiency or systemic immunosuppressant drugs.

BackgroundProspective population-based studies investigating multiple determinants of pre-vaccination antibody responses to SARS-CoV-2 are lacking.MethodsWe did a prospective population-based study in SARS-CoV-2 vaccine-naive UK adults recruited between May 1 and November 2, 2020, without a positive swab test result for SARS-CoV-2 prior to enrolment. Information on 88 potential sociodemographic, behavioural, nutritional, clinical and pharmacological risk factors was obtained through online questionnaires, and combined IgG/IgA/IgM responses to SARS-CoV-2 spike glycoprotein were determined in dried blood spots obtained between November 6, 2020 and April 18, 2021. We used logistic and linear regression to estimate adjusted odds ratios (aORs) and adjusted geometric mean ratios (aGMRs) for potential determinants of SARS-CoV-2 seropositivity (all participants) and antibody titres (seropositive participants only), respectively.Results1696 (15.2%) of 11,130 participants were seropositive. Factors independently associated with increased risk of SARS-CoV-2 seropositivity included frontline health/care occupation (aOR 1.86, 95% CI 1.48–2.33), international travel (1.20, 1.07–1.35), number of visits to shops and other indoor public places (≥5 vs. 0/week: 1.29, 1.06-1.57, P-trend=0.01), body mass index (BMI) ≥25 vs 2 (1.24, 1.11–1.39), Asian/Asian British vs White ethnicity (1.65, 1.10–2.49), and alcohol consumption ≥15 vs 0 units/week (1.23, 1.04–1.46). Light physical exercise associated with decreased risk (0.80, 0.70–0.93, for ≥10 vs 0–4 h/week). Among seropositive participants, higher titres of anti-Spike antibodies associated with factors including BMI ≥30 vs 2 (aGMR 1.10, 1.02–1.19), Asian/Asian British vs White ethnicity (1.22, 1.04–1.44), frontline health/care occupation (1.24, 95% CI 1.11–1.39), international travel (1.11, 1.05–1.16), and number of visits to shops and other indoor public places (≥5 vs. 0/week: 1.12, 1.02-1.23, P-trend=0.01); these associations were not substantially attenuated by adjustment for COVID-19 disease severity.ConclusionsHigher alcohol consumption and reduced light physical exercise represent new modifiable risk factors for SARS-CoV-2 infection. Recognised associations between Asian/Asian British ethnic origin and obesity and increased risk of SARS-CoV-2 seropositivity were independent of other sociodemographic, behavioural, nutritional, clinical and pharmacological factors investigated. Among seropositive participants, higher titres of anti-Spike antibodies in people of Asian ancestry and in obese people were not explained by greater COVID-19 disease severity in these groups.FundingBarts Charity, Health Data Research UK.

Background: Prospective population-based studies investigating multiple determinants of pre-vaccination antibody responses to SARS-CoV-2 are lacking. Methods: We did a prospective population-based study in SARS-CoV-2 vaccine-naive UK adults between May 1 and Nov 2, 2020. Information on 88 potential risk factors was obtained through online questionnaires, and combined IgG/IgA/IgM responses to SARS-CoV-2 spike glycoprotein were determined in dried blood spots. We used logistic and linear regression to estimate adjusted odds ratios (aORs) and adjusted geometric mean ratios (aGMRs) for potential determinants of SARS-CoV-2 seropositivity (all participants) and antibody titres (seropositive participants only), respectively. Findings: 1696 (15.2%) of 11,130 participants were seropositive. Factors independently associated with increased risk included frontline health/care occupation (aOR 1.86, 95% CI 1.49–2.33), international travel (1.22, 1.08–1.37), BMI >30 vs 30 vs