Diversified humoral immunity and impacts of booster vaccines: SARS-CoV-2 antibody profile and Omicron BA.2 neutralization before and after first or second boosters.

This study aims to investigate humoral immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and assess the impact of booster vaccines. We recruited individuals scheduled to receive either the first (original formula) or the second (bivalent) booster following the initial two-dose SARS-CoV-2 vaccination. We tested for IgG antibodies targeting the spike protein receptor-binding domain (RBD), S1, S2, and nucleocapsid protein, as well as for neutralizing antibodies against Omicron BA.2, before and 14-28 days after receiving the boosters. One year after receiving the initial series of vaccinations, all participants maintained anti-RBD/S1 antibodies. However, levels were lower in individuals who were vaccinated only compared to those who had both vaccination and prior infection (hybrid immunity). Participants with hybrid immunity also showed higher retention of neutralizing antibodies (93% compared to 24% in vaccine-only individuals). Even before receiving any booster shots, participants with hybrid immunity had antibody levels similar to those of vaccine-only individuals after their first booster. After receiving booster shots, antibody levels at 14-28 days were similar regardless of the number of boosters or the type of immunity. About 1 year after the first booster, all participants maintained neutralizing antibodies, and vaccine-only individuals retained about 10 times higher levels of binding antibodies than those without a booster. Humoral immunity varies widely among individuals, and vaccination planning should consider both vaccination and infection history. Boosters are beneficial for increasing antibody levels to ensure sufficient protection against infection and helping bridge the immunity gap between vaccine-only and hybrid immunity.IMPORTANCEAs we move into the era of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine boosters and shifting from pandemic to endemic, the landscape has changed for both the circulating SARS-CoV-2 variants and population immunity. Even though recent waves of infection have been clinically milder than earlier variants due to the high levels of population immunity and the properties of the Omicron subvariants, vaccination remains crucial for managing COVID-19 in the post-pandemic era. Our study unveils significant variations in the retention of anti-SARS-CoV-2 binding antibody profiles and neutralizing antibody levels 1 year after the primary and the first booster mRNA vaccination. It adds new information regarding how boosters change antibody levels and durability in individuals with hybrid (vaccination plus infection) or vaccine-only (never-infected) immunity. The findings can shed light on future vaccination planning.

The humoral response to SARS-COV-2 vaccines in MS patients: A case series exploring the impact of DMT, lymphocyte count, immunoglobulins, and vaccine type.

BACKGROUND & OBJECTIVES: Certain disease modifying therapies may negatively impact the humoral response to SARS-CoV-2 vaccines. Many MS related clinical, demographic, and immunological characteristics can also affect vaccine response but those have not been fully explored. This study aimed to investigate potential correlations between clinical, demographic, and immunological variables in MS patients to post-vaccination spike protein antibody positivity rates and levels. METHODS: Patients with MS and related neuroimmunological disorders who requested verification of the immune response to the SARS-COV-2 vaccine were tested for the spike protein antibody from January to October 2021. We performed an exploratory analysis to compare patients with positive versus negative spike protein antibody. RESULTS: Fifty patients (mean age 53 ±12, 78% females) were included. There were 29 patients with positive post-vaccination spike protein antibody (58%) and 21 with negative antibody (42%). Patients with negative antibody were more likely to have been on B-cell therapy (86% vs 31%, P=.001) while positive patients were more likely to have been on a fumarate (31% vs 4.8%, P=.03). Thirty percent of positive patients on fumarate therapy had mild lymphopenia. No differences existed between groups in gender, age, race, disease phenotype, vaccine brand, and lymphocyte counts. Among patients on B-cell therapy, 33% had a positive spike protein antibody. There was an association between detectable CD19 cells at time of vaccination and positive humoral response to vaccination (P=0.049). There was no relationship between subgroups in terms of vaccine timing relative to B-cell therapy dose. Hypogammaglobulinemia was not associated with seroconversion rates, however it was associated with decreased quantitative spike protein antibody levels (p=0.045). DISCUSSION: B-cell therapy is associated with a negative humoral response to SARS-COV-2 vaccines. Patients on B-cell depleting therapy with detectable CD19 counts at the time of vaccination were associated with a positive humoral response. There was no relationship between hypogammaglobinemia and seroconversion rate, however it was associated with decreased spike protein antibody levels. The fumarates are associated with positive humoral response even in the presence of mild lymphopenia.

Pediatric Case of Severe COVID-19 With Shock and Multisystem Inflammation.

While the majority of pediatric coronavirus disease 2019 (COVID-19) cases have not been critical, occurrences of a multisystem inflammatory syndrome in children (MIS-C) have been emerging as the pandemic progresses. Herein, we report our experience with a pediatric COVID-19 case that presented with shock and multisystem inflammation. Our patient notably had multiple negative severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcription polymerase chain reaction (RT-PCR) assays but tested positive for SARS-CoV-2 IgG antibody. This case not only highlights the utility of SARS-CoV-2 IgG in the diagnosis of COVID-19 when RT-PCR is negative but suggests MIS-C may be a post-infectious immune-mediated process.