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The SARS-CoV-2 pandemic enables the analysis of immune responses induced against a novel coronavirus infecting immunologically naïve individuals. This provides an opportunity for analysis of immune responses and associations with age, sex and disease severity. Here we measured an array of solid-phase binding antibody and viral neutralising Ab (nAb) responses in participants (n=337) of the ISARIC4C cohort and characterised their correlation with peak disease severity during acute infection and early convalescence. Overall, the responses in a Double Antigen Binding Assay (DABA) for antibody to the receptor binding domain (anti-RBD) correlated well with IgM as well as IgG responses against viral spike, S1 and nucleocapsid protein (NP) antigens. DABA reactivity also correlated with nAb. As we and others reported previously, there is greater risk of severe disease and death in older men, whilst the sex ratio was found to be equal within each severity grouping in younger people. In older males with severe disease (mean age 68 years), peak antibody levels were found to be delayed by one to two weeks compared with women, and nAb responses were delayed further. Additionally, we demonstrated that solid-phase binding antibody responses reached higher levels in males as measured via DABA and IgM binding against Spike, NP and S1 antigens. In contrast, this was not observed for nAb responses. When measuring SARS-CoV-2 RNA transcripts (as a surrogate for viral shedding) in nasal swabs at recruitment, we saw no significant differences by sex or disease severity status. However, we have shown higher antibody levels associated with low nasal viral RNA indicating a role of antibody responses in controlling viral replication and shedding in the upper airway. In this study, we have shown discernible differences in the humoral immune responses between males and females and these differences associate with age as well as with resultant disease severity. [ABSTRACT FROM AUTHOR]

The immune impairment related to some haematological malignancies and their treatments is considered responsible for the more severe COVID-19 [[1]] and the lower response rate to anti-SARS-CoV-2 vaccines in these patients [[2], [4]]. A total of 481 serological tests (Supplementary Figure 1) were performed over 9 months on 312 CML patients and we found 35 patients (11.2%) to be seropositive, of whom 23 (65.7%) recalled COVID-19 symptoms in the previous months and 12 (34.3%) were asymptomatic. Anti-SARS-CoV-2 seroprevalence, COVID-19 symptoms and persistence of natural anti-RBD antibodies in CML patients. [Extracted from the article]

At T3, 51/52 patients (98%) and 29/29 HS (100%) were seropositive, a finding that persisted at T4 (45/46 patients and 26/26 HS) with a single patient failing to seroconvert at any time. Keywords: CML; TKI; SARS-CoV-2; COVID-19; vaccines EN CML TKI SARS-CoV-2 COVID-19 vaccines e1 e4 4 03/30/22 20220401 NES 220401 The COVID-19 pandemic is a serious healthcare challenge, leading to more than 5 million deaths worldwide so far. At the time of their first vaccine dose, most patients ( I n i = 41, 76%) were receiving a 2 SP nd sp /3 SP rd sp -generation or newer TKI (which were dasatinib, nilotinib, bosutinib, ponatinib and asciminib in 21, 7, 5, 2 and 6 patients, respectively); 27 and 27 patients were in major molecular response and in deep molecular response, respectively. [Extracted from the article]

At-home sampling is key to large scale seroprevalence studies. Dried blood spot (DBS) self-sampling removes the need for medical personnel for specimen collection but facilitates specimen referral to an appropriately accredited laboratory for accurate sample analysis. To establish a highly sensitive and specific antibody assay that would facilitate self-sampling for prevalence and vaccine-response studies. Paired sera and DBS eluates collected from 439 sero-positive, 382 sero-negative individuals and DBS from 34 vaccine recipients were assayed by capture ELISAs for IgG and IgM antibody to SARS-CoV-2. IgG and IgM combined on DBS eluates achieved a diagnostic sensitivity of 97.9% (95%CI 96.6 to 99.3) and a specificity of 99.2% (95% CI 98.4 to 100) compared to serum, displaying limits of detection equivalent to 23 and 10 WHO IU/ml, respectively. A strong correlation (r = 0.81) was observed between serum and DBS reactivities. Reactivity remained stable with samples deliberately rendered inadequate, (p = 0.234) and when samples were accidentally damaged or 'invalid'. All vaccine recipients were sero-positive. This assay provides a secure method for self-sampling by DBS with a sensitivity comparable to serum. The feasibility of DBS testing in sero-prevalence studies and in monitoring post-vaccine responses was confirmed, offering a robust and reliable tool for serological monitoring at a population level. [ABSTRACT FROM AUTHOR]

It is currently unknown how post-COVID-19 syndrome (PCS) may affect those infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This longitudinal study includes healthcare staff who tested positive for SARS-CoV-2 between March and April 2020, with follow-up of their antibody titers and symptoms. More than half (21 of 38) had PCS after 7-8 months. There was no statistically significant difference between initial reverse-transcription polymerase chain reaction titers or serial antibody levels between those who did and those who did not develop PCS. This study highlights the relative commonality of PCS in healthcare workers and this should be considered in vaccination scheduling and workforce planning to allow adequate frontline staffing numbers. [ABSTRACT FROM AUTHOR]