Analysis and comparison of SARS-CoV-2 variant antibodies and neutralizing activity for 6 months after a booster mRNA vaccine in a healthcare worker population

Introduction

In the context of recurrent surges of SARS-CoV-2 infections, a detailed characterization of antibody persistence over a 6-month period following vaccine booster dose is necessary to crafting effective public health policies on repeat vaccination.

Methods

To characterize the SARS-CoV-2 antibody profile of a healthcare worker population over a 6-month period following mRNA vaccination and booster dose. 323 healthcare workers at an academic medical center in Orange County, California who had completed primary vaccination and booster dose against SARS-CoV-2 were recruited for the study. A total of 690 blood specimens over a 6-month period were collected via finger-stick blood and analyzed for the presence of antibodies against 9 SARS-CoV-2 antigens using a coronavirus antigen microarray.

Results

The primary outcome of this study was the average SARS-CoV-2 antibody level as measured using a novel coronavirus antigen microarray. Additional outcomes measured include levels of antibodies specific to SARS-CoV-2 variants including Delta, Omicron BA.1, and BA.2. We also measured SARS-CoV-2 neutralization capacity for a subset of the population to confirm correlation with antibody levels. Although antibodies against SARS-CoV-2 wane throughout the 6-month period following a booster dose, antibody levels remain higher than pre-boost levels. However, a booster dose of vaccine based on the original Wuhan strain generates approximately 3-fold lower antibody reactivity against Omicron variants BA.1 and BA.2 as compared to the vaccine strain. Despite waning antibody levels, neutralization activity against the vaccine strain is maintained throughout the 6-month period.

Discussion

In the context of recurrent surges of SARS-CoV-2 infections, our data indicate that breakthrough infections are likely driven by novel variants with different antibody specificity and not by time since last dose of vaccination, indicating that development of vaccinations specific to these novel variants is necessary to prevent future surges of SARS-CoV-2 infections.

Analysis and comparison of SARS-CoV-2 variant antibodies and neutralizing activity for 6 months after a booster mRNA vaccine in a healthcare worker population

In the context of recurrent surges of SARS-CoV-2 infections, a detailed characterization of antibody persistence over a 6-month period following vaccine booster dose is necessary to crafting effective public health policies on repeat vaccination. To characterize the SARS-CoV-2 antibody profile of a healthcare worker population over a 6-month period following mRNA vaccination and booster dose. 323 healthcare workers at an academic medical center in Orange County, California who had completed primary vaccination and booster dose against SARS-CoV-2 were recruited for the study. A total of 690 blood specimens over a 6-month period were collected via finger-stick blood and analyzed for the presence of antibodies against 9 SARS-CoV-2 antigens using a coronavirus antigen microarray. The primary outcome of this study was the average SARS-CoV-2 antibody level as measured using a novel coronavirus antigen microarray. Additional outcomes measured include levels of antibodies specific to SARS-CoV-2 variants including Delta, Omicron BA.1, and BA.2. We also measured SARS-CoV-2 neutralization capacity for a subset of the population to confirm correlation with antibody levels. Although antibodies against SARS-CoV-2 wane throughout the 6-month period following a booster dose, antibody levels remain higher than pre-boost levels. However, a booster dose of vaccine generates approximately 3-fold lower antibody reactivity against Omicron variants BA.1 and BA.2 as compared to the original Wuhan strain. Despite waning antibody levels, neutralization activity against the original Wuhan strain is maintained throughout the 6-month period. In the context of recurrent surges of SARS-CoV-2 infections despite vaccination with booster doses, our data indicate that breakthrough infections are likely driven by novel variants with different antibody specificity and not by time since last dose of vaccination, indicating that development of vaccinations specific to these novel variants is necessary to prevent future surges of SARS-CoV-2 infections.

Recurrent anaphylaxis due to lupin flour: primary sensitization through inhalation

Allergic reactions to lupin have increased in parallel with the growing use of lupin flour by food manufacturers. We studied a patient with recurrent anaphylaxis to manufactured foods and a history of rhinitis-asthma related to lupin inhalation and legume tolerance. Skin prick tests with airborne and food allergens, specific immunoglobulin (Ig) E determinations, and an inhalation exposure test to ground lupin were carried out. Lupin allergens and cross-reactivity with other legumes were also studied using sodium dodecyl sulfate polyacrylamide gel electrophoresis and immunoblotting/immunoblotting inhibition. The skin tests and specific IgE were positive for lupin and vetchling and negative for other legumes. The presence of lupin flour in the implicated foods was confirmed. Immunoblotting showed multiple IgE-binding bands (10-40 kDa) for lupin and vetchling but not for peanut, pea, or soy extracts. Immunoblotting inhibition demonstrated intense lupin-vetchling cross-reactivity. We present a case of recurrent anaphylaxis due to lupin flour as a hidden food allergen with primary sensitization due to exposure to ground lupin via inhalation. We found cross-reactivity between lupin and vetchling but not other legumes.