DOI: 10.5061/dryad.1vhhmgr49
title: Increased number of COVID-19 boosters increases the longevity of anti-RBD and anti-RBD neutralizing antibodies

description: Since the World Health Organization declared COVID-19 a pandemic in March
 2020, the virus has caused multiple waves of infection globally. The
 largest four-year public university in the United States, offers a
 uniquely diverse setting for assessing immunity within a large community.
 This study aimed to evaluate SARS-CoV-2 antibody seroprevalence and the
 effects of infection and vaccination three years into the pandemic. A
 serosurvey was conducted at the public university in early 2023.
 Participants completed questionnaires about demographics, respiratory
 infection history, symptoms, and COVID-19 vaccination status. Blood
 samples were analyzed for anti-receptor binding domain (RBD) IgG and
 anti-nucleocapsid (NC) antibodies, offering a comprehensive view of
 immunity from both natural infection and vaccination. The seroprevalence
 of anti-RBD IgG antibodies was 96.2% (95% CI: 94.8%-97.2%), and 64.9% of
 participants had anti-NC antibodies (95% CI: 61.9%-67.8%). Anti-RBD IgG
 levels correlated strongly with neutralizing antibody levels, and
 participants who received more vaccine doses showed higher levels of both
 anti-RBD IgG and neutralizing antibodies. Increasing number of exposures
 through vaccination and/or infection resulted in higher and long-lasting
 antibodies. Conclusion: The high levels of anti-RBD antibodies observed
 reflect substantial vaccine uptake within this population. Ongoing
 vaccination efforts, especially as new variants emerge, are essential to
 maintaining antibody levels. These findings underscore the importance of
 sustained public health initiatives to support broad-based immunity and
 protection.
description: The study was approved by the institutional Review Board. The
 study population comprised students and employees recruited in early, 2021
 at the University. Recruitment for this study was conducted through
 invitations, email announcements to the university community, and social
 media advertising, and potential participants were required to complete an
 electronic consent and a survey before giving biological specimens. The
 sample collection was extended for three days, in early, 2023.
 Participants were initially invited via emails and social media channels.
 Individuals were eligible for inclusion if they were 18 years of age or
 older and were able to provide informed consent. 999 individuals,
 including students and employees, who completed the screening, provided
 informed consent, and filled out the initial survey forms, were
 successfully recruited for the study. Participants were compensated for
 their time and efforts towards completing the survey and submitting
 samples.  Individuals under 18, those unable to provide consent, pregnant
 women, or those weighing less than 110 lbs. at the time of the survey were
 excluded Demographic information, COVID-19 vaccination
 status, testing history, and symptoms were collected through a
 self-reported questionnaire. Participants voluntarily provided this
 information and were compensated after providing samples. Blood samples
 were collected by trained phlebotomists.  
description: # Serosurvey -3 at the large public university
 [https://doi.org/10.5061/dryad.1vhhmgr49](https://doi.org/10.5061/dryad.1vhhmgr49) ## Description of the data and file structure The study was approved by the institutional Review Board. The study population comprised students and employees recruited in early, 2021 at the University. Recruitment for this study was conducted through invitations, email announcements to the university community, and social media advertising, and potential participants were required to complete an electronic consent and a survey before giving biological specimens. The sample collection was extended for three days, in early, 2023. Participants were initially invited via emails and social media channels. Individuals were eligible for inclusion if they were 18 years of age or older and were able to provide informed consent. 999 individuals, including students and employees, who completed the screening, provided informed consent, and filled out the initial survey forms, were successfully recruited for the study. Participants were compensated for their time and efforts towards completing the survey and submitting samples.  Individuals under 18, those unable to provide consent, pregnant women, or those weighing less than 110 lbs. at the time of the survey were excluded Demographic information, COVID-19 vaccination status, testing history, and symptoms were collected through a self-reported questionnaire. Participants voluntarily provided this information and were compensated after providing samples. Blood samples were collected by trained phlebotomists. All demographic information and assay results were provided via Excel files. Any participant under the age of 18, those who did not provide a biological sample, or those with non-unique sample IDs were removed from the study. Assay information was first merged together by a sample ID and those in common were kept in the study (inner join). The combined assay data was then merged to the demographic information. Those who provided biological samples but no demographic information were removed from the study (left join). Finally, we performed data cleaning in order to fix input mistakes (e.g. spelling, wrong dates, etc.) and group responses in the appropriate categories. We corrected input mistakes by participants (e.g. wrong spelling of vaccine source). We also checked whether the vaccination dates were sequential. For example, if the second vaccination date was reported before the first vaccination date, then the second vaccination date was recorded as missing (NA).  ### Missing and Incomplete Data: Certain cells are empty when the data is not available, not collected or assays are not performed. ### Files and variables #### File: Serosurvey-3.xlsx **Description:** | **Variable** | **Type** | **Description** | **Additional Descriptions** | | :------------------------ | :-------- | :------------------------------------------------------------------ | :------------------------------------------------------------------------------------------ | | surv.type | Character | Indicator of survey the participant took part in | ·       sero3: Serosurvey III | | pseudoid | numeric | Deidentified patient ID | | | age.gr2 | Character | Age group | ·       Participants who did not respond were labeled as NA | | gender | Character | Gender | ·       Others: non-binary, third gender & prefer not to say | | status | Character | Employment status: | ·       empl:  employees | | howheard1 | Character | How they heard about the study | ·       Ad: Advertisement | | covid19 | Character | Have you ever been diagnosed with covid? | ·       Participants who did not respond were labeled as NA | | vaccine | Character | Have you been vaccinated for COVID-19? | | | vaccine.source | Character | Vaccine Source: | ·       Mixed: participants who received more than one vaccine source | | vaccine.num | Numeric | Number of vaccines participant received | ·       Participants who did not respond were labeled as NA | | covid19.num | Numeric | Number of times participant was diagnosed with covid | ·       Participants who did not respond were labeled as NA | | last.vac.to.survey.mo | Numeric | Time from last vaccination to survey date, in months | ·       Participants who did not provide vaccine dates were labeled as NA | | last.vac.to.survey.mo.grp | Character | Time from last vaccination to survey date, in months (grouped): | ·       Participants who did not provide vaccine dates were labeled as NA | | vac.num.grp | Character | Number of vaccines participant received (grouped) | ·       Number of vaccines calculated using vaccine.num | | exp.to.survey.mo | Numeric | Time from last vaccination or infection to survey date, in months | ·       Vaccinations and infections were considered “exposures” (exp). | | exp.num.grp | Character | Number of vaccines and/or infections participant received (grouped) | ·       Number of exposures calculated using vaccine.num and covid19.num | | Spike.Dxi.IgG.value2 | Numeric | Value for Spike Dxi IgG results, after dilution | ·       Anything &gt; 10 was considered positive. Otherwise, negative. | | Spike.Dxi.IgG | Character | Spike Dxi IgG results: | | | NC.ELISA.value | Numeric | Value for NC ELISA results | | | NC.ELISA | Character | ELISA results: | | | qPCR\_result | Character | Saliva qPCR results: | | | Pct.Neut | | Percent Neutralizing Antibodies | ·       Participants with insufficient sample volume to perform the assay were marked as NA | ## Code/software Microsoft Excel can be used to view the file.