Longitudinal evaluation of the Abbott ARCHITECT SARS-CoV-2 IgM and IgG assays in a pediatric population

COVID-19 severity and corticosteroid treatment have minimal effect on specific antibody production

BACKGROUND

Dexamethasone is currently administered for Coronavirus disease 2019(COVID-19); however, there are concerns about its effect on specific antibodies' production. The aim of this study was to evaluate whether specific antibodies were affected by COVID-19 severity and corticosteroid treatment.

METHODS

Of 251 confirmed COVID-19 patients admitted to our hospital between January 26 and August 10, 2020, the early period of the pandemic, 75 patients with sera within 1 month of onset and 1 month or longer were included in the research. A total of 253 serum samples from these patients were collected. The levels of specific antibodies for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2), immunoglobulin G (IgG) and M (IgM), were measured retrospectively. The results were compared separately of each COVID-19 severity, and with or without corticosteroid treatment.

RESULTS

Among the 75 patients, 47, 18, and 10 had mild, moderate, and severe disease, respectively. The median age was 53.0 years and 22 (29%) were women. The most common comorbidities were hypertension and dyslipidemia. Corticosteroids were administered to 20 (27%) and 10 (53%), patients with moderate and severe disease, respectively. The positivity rates IgM increased first, and IgG was almost always positive after day 16, regardless of the severity of COVID-19. On days 6-10, both IgG and IgM positivity rates were higher in patients with moderate disease than in those with mild or severe disease. In patients with moderate disease, IgG positivity was similar over time, regardless of corticosteroid treatment.

CONCLUSIONS

In COVID-19 patients, specific IgG is positive and maintained for a long period of time, even after corticosteroid treatment. The effect of corticosteroid treatment in a COVID-19 epidemiological study using specific IgG antibodies was considered minor. COVID-19 patients were more likely to receive oxygen if IgM was positive 1 week after onset, but not mechanical ventilation. IgM measurement 1 week after onset may predict COVID-19 severity.

Severe acute respiratory syndrome coronavirus 2 seroprevalence and longitudinal antibody response following natural infection in pregnancy: A prospective cohort study

BACKGROUND

Antenatal care provides unique opportunities to assess severe acute respiratory syndrome coronavirus 2 seroprevalence and antibody response duration after natural infection detected during pregnancy; transplacental antibody transfer may inform peripartum and neonatal protection. We estimated seroprevalence and durability of antibodies from natural infection (anti-nucleocapsid immunoglobulin G) among pregnant people, and evaluated transplacental transfer efficiency.

OBJECTIVE AND DESIGN

We conducted a cross-sectional study to measure severe acute respiratory syndrome coronavirus 2 seroprevalence, and a prospective cohort study to longitudinally measure anti-nucleocapsid immunoglobulin G responses and transplacental transfer of maternally derived anti-nucleocapsid antibodies.

METHODS

We screened pregnant people for the seroprevalence study between 9 December 2020 and 19 June 2021 for anti-nucleocapsid immunoglobulin G in Seattle, Washington. We enrolled anti-nucleocapsid immunoglobulin G positive people from the seroprevalence study or identified through medical records with positive reverse transcription polymerase chain reaction or antigen positive results in a prospective cohort between 9 December 2020 and 9 August 2022.

RESULTS

In the cross-sectional study (N = 1284), 5% (N = 65) tested severe acute respiratory syndrome coronavirus 2 anti-nucleocapsid immunoglobulin G positive, including 39 (60%) without prior positive reverse transcription polymerase chain reaction results and 42 (65%) without symptoms. In the prospective cohort study (N = 107 total; N = 65 from the seroprevalence study), 86 (N = 80%) had anti-nucleocapsid immunoglobulin G positive results during pregnancy. Among 63 participants with delivery samples and prior anti-nucleocapsid positive results, 29 (46%) were anti-nucleocapsid immunoglobulin G negative by delivery. Of 34 remaining anti-nucleocapsid immunoglobulin G positive at delivery with paired cord blood, 19 (56%) had efficient transplacental anti-nucleocapsid immunoglobulin G antibody transfer. Median time from first anti-nucleocapsid immunoglobulin G positive to below positive antibody threshold was 19 weeks and did not differ by prior positive reverse transcription polymerase chain reaction status.

CONCLUSIONS

Maternally derived severe acute respiratory syndrome coronavirus 2 antibodies to natural infection may wane before delivery. Vaccines are recommended for pregnant persons to reduce severe illness and confer protection to infants.

The SARS-CoV-2 pandemic in Germany may represent the sum of a large number of local but independent epidemics each initiated by individuals aged 10 - 19 years, middle aged males, or elderly individuals

Many epidemiological aspects of the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) pandemics, particularly those affecting children, are still sparsely elucidated. Data on the first pandemic phase during the year 2020 indicated that children might serve as a virus reservoir. We now analyzed data on more than 530 000 SARS‐CoV‐2 polymerase chain reaction (PCR) and 12 503 anti‐SARS‐CoV‐2 antibody tests performed in the west of Germany until Week 4 of 2021. We show that children of at least 10 years of age may play a prominent role in the pandemic showing highest PCR‐positive rates in the first (Weeks 28–35), second (Weeks 42–48), and third wave (Week 50 of 2020–Week 2 2021) of the second pandemic phase, although the waves were not mainly initiated by children. The waves' kinetics differed even in nearby cities. Low PCR‐positive rates were confined to areas of lower population density. PCR‐positive rates were higher among middle‐aged males compared with women and among very old females compared with males. From Week 25, seroprevalence rates slowly increased to 50%, indicating ongoing virus activity. In conclusion, the SARS‐CoV‐2 pandemics is characterized by many local but interacting epidemics, initiated and driven by different social groups. Children may not be the main initiators of virus spreading but older children may significantly affect the course of the pandemic. High population density is associated with higher SARS‐CoV‐2 incidence.

Long-Term Persistence of Anti-SARS-CoV-2 Antibodies in a Pediatric Population

Background: Antibody dynamics over time after SARS-CoV-2 infection are still unclear, and data regarding children are scarce. Methods: A prospective cohort study was performed including children infected by SARS-CoV-2 between March and May 2020. Patients were categorized into 3 groups: children admitted with COVID-19; outpatient children with mild COVID-19; and seropositive children participating in a seroprevalence study among cohabitants of infected healthcare workers (HCWs). Six months after the infection, a new serological control was performed. Results: A total of 58 children were included, 50% male (median age 8.3 [IQR 2.8–13.5] years). The median time between the two serological studies was 186 (IQR 176–192) days, and 86% (48/56) of the children maintained positive IgG six months after the infection. This percentage was 100% in admitted patients and 78% among the rest of the included children (p = 0.022). The diagnoses of lower respiratory tract infection and multisystemic inflammatory syndrome were associated with persistence of IgG (p = 0.035). The children of HCWs in the seroprevalence study lost antibodies more often (p = 0.017). Initial IgG titers of the children who remained positive six months after the infection were significantly higher (p = 0.008). Conclusions: Most children infected by SARS-CoV-2 maintain a positive serological response six months after the infection. Those children who lost their IgG titer were more frequently asymptomatic or mildly symptomatic, presenting with low antibody titers after the infection.

Dataset for longitudinal evaluation of the Abbott ARCHITECT SARS-CoV-2 IgM and IgG assays in a pediatric population divided by age

Background

SARS-CoV-2 infection in children does not seem to follow the same pattern as in adults. Limited information is published on the level of antibody production and the duration of antibody response in children with COVID-19. Moreover, it is unknown if all children have a similar immune response to the infection, or if there are age dependent differences. In these data, we look at the IgM and IgG levels and duration of two age groups infected by the SARS-CoV-2 virus.

Methods

Residual laboratory specimens from pediatric patients positive for SARS-CoV-2 infection were tested for IgM and IgG against SARS-CoV-2 using an automated Abbott ARCHITECT i1000. We tested 181 specimens from 41 patients with a positive molecular result. Data was grouped either as time after nucleic acid amplification test (NAAT) or time after symptom onset. Patient samples were divided into 2 age groups: 0 to 11 years old and 12 to 19 years old. The assays detect IgM against the spike protein and IgG against the nucleocapsid protein.