SARS-CoV-2 antibody responses post-vaccination in UK healthcare workers with pre-existing medical conditions: a cohort study

Abstract

ObjectivesTo examine antibody responses after the second vaccination in healthcare workers (HCWs) with underlying health conditions.DesignCohort study.SettingOxford University Hospitals in the United Kingdom.ParticipantsHealthcare workers who had SARS-CoV-2 serological data available and received two SARS-CoV- 2 vaccinations.Primary outcomePeak SARS-CoV-2 anti-spike IgG responses after the second vaccination and associations with underlying health conditions and the estimated risk of severe COVID-19 using an occupational health risk assessment tool.MethodsWe used univariable and multivariable linear regression models to investigate associations between antibody levels and demographics (age, sex, ethnicity), healthcare role, body mass index, underlying health conditions, vaccination status, prior infection and the Association of Local Authority Medical Advisors COVID-age risk score.Results1635 HCWs had anti-spike IgG measurements 14–84 days after second vaccination and data on any underlying health conditions. Only five HCWs (0.3%), all on immunosuppressive treatment, (including four organ transplant recipients), did not seroconvert after second vaccination. Antibody levels were independently lower with older age, diabetes, immunosuppression, respiratory disorders other than asthma and markedly so in organ transplant recipients. Levels were independently lower in ChAdOx1 versus BNT162b2 recipients and higher following previous infection. HCWs with ‘very high’ COVID-age risk scores had lower median antibody levels than those with ‘low’, ‘medium’ or ‘high’ risk scores; 4379 AU/mL, compared with 12 337 AU/mL, 9430 AU/mL and 10 524 AU/mL, respectively.ConclusionsTwo vaccine doses are effective in generating antibody responses among HCWs, including those with a high occupational risk. However, HCWs with underlying health conditions, especially diabetes, immunosuppression and organ transplant, had lower antibody levels, and vaccine response monitoring may be needed.

Association between antibody responses post-vaccination and severe COVID-19 outcomes in Scotland

“…Our findings confirm previously reported associations between the following risks or characteristics and a suboptimal antibody response following vaccination (individuals may fall into more than one risk group): cancers 7 , 20 , 21 , obesity 7 , 22 , 23 , use of immunosuppressant therapies 6 , 20 , 21 , 24 , 25 , being on the shielded patient list 25 and age 6 , 7 , 26 . Our findings of a greater likelihood of testing negative for antibodies post-vaccination among specific clinical risk groups (those with kidney disease 7 , 27 , cirrhosis 28 , diabetes 7 , 29 , haematological cancers 30 – 32 , and neurological conditions 7 , 33 ) were also consistent with the published literature, although in some of these conditions a diminished immune response may be attributable to therapies used to treat the condition rather than the condition itself. We did not however observe any association between socioeconomic status or sex and antibody response – the latter finding in contrast to previously published results, which have demonstrated higher SARS-CoV-2 IgG levels among females 7 , 26 .…”

Association between Antibody Responses Post-Vaccination and Severe COVID-19 Outcomes: National Population-Based Cohort Study in Scotland

“…Our findings confirm previously reported associations between the following risks or characteristics and a suboptimal antibody response following vaccination (individuals may fall into more than one risk group): cancers 7,17,18 , obesity 7,19,20 , use of immunosuppressant therapies 6,17,18,21,22 , being on the shielded patient list 22 and age 6,7,23 . Our findings of a greater likelihood of testing negative for antibodies post-vaccination among specific clinical risk groups (those with kidney disease 7,24 , cirrhosis 25 , diabetes 7,26 , haematological cancers [27][28][29] , and neurological conditions 7,30 ) were also consistent with the published literature, although in some of these conditions a diminished immune response may be attributable to therapies used to treat the condition rather than the condition itself. We did not however observe any association between socioeconomic status or sex and antibody responsethe latter finding in contrast to previously published results, which have demonstrated higher SARS-CoV-2 IgG levels among females 7,23 .…”

Ethnic differences in cellular and humoral immune responses to SARS-CoV-2 vaccination in UK healthcare workers: a cross-sectional analysis

“…In contrast, another UK HCW study found Black HCW to have lower serologic responses to vaccination than their White counterparts and found no differences between the White and Asian groups. 23 …”

“… 16 , 17 , 18 , 19 , 20 , 21 A recent study reporting findings from a large cohort of UK healthcare workers (HCWs) found higher SARS-CoV-2 anti-spike titres in ethnic minority vaccinees than in their White counterparts, 22 which contrasts with another UK HCW study which found lower peak anti-spike antibody titres in Black HCWs compared to White HCWs and did not find differences between the White and Asian groups. 23 A large UK observational study in the general population found South Asians vaccinees to have higher combined IgG, A and M titres against SARS-CoV-2 than those from White groups. 24 Crucially, there are no studies that present data relating to both cellular immune responses and SARS-CoV-2 neutralising activity after vaccination stratified by ethnicity.…”