Vaccination Of Healthcare Workers Research Articles

SARS-CoV-2 antibody response after BNT162b2 mRNA vaccine in healthcare workers: Nine-month of follow-up

We collected sequential serum samples (0, 4, 12 weeks, 9 months) for the determination of S-RDB IgG levels from 103 vaccinated healthy subjects (age 45 ± 13 years; 60 women), in order to evaluate neutralizing antibody response against SARS-CoV-2 in healthy healthcare workers (HCWs) after the administration of two doses of BNT162b2 SARS-CoV-2 mRNA vaccine. Every subject received two doses of mRNA vaccine BNT162b2 (Pfizer-BioNTech), 21 days apart (January-February 2021). Furthermore, antibody titer of 14 subjects who were hospitalized for symptomatic COVID-19 was evaluated. Antibody response was (median, interquartile range) 35 U/mL (10–104) at baseline, 1960 (1241–3221) at 4 weeks, 791 (388–1179) at 12 weeks and 524 (273–931) at 6 months. Antibody response was inversely correlated with age at all timepoints (p < 0.001) while gender and Body Mass Index had no significant effect. At multivariate analysis, post-baseline values were significantly higher than baseline (p < 0.001) with a reduction at 12 weeks and 9 months (p < 0.001). Antibody response of hospitalized subjects who did not receive vaccination, symptomatic for COVID 19 infection, was 103 (25–557) U/mL, significantly higher than baseline (p = 0.007) of study population but lower than all post-baseline determinations (p < 0.001). Younger subjects showed a stronger response and a lower decrease of antibody titers compared to the classes of older subjects. SARS-CoV2 infection was excluded by performing 1017 nasopharyngeal RT-PCR swabs on the study cohort. The second dose of mRNA vaccine resulted in an antibody response effective in preventing infection in a population of healthcare professionals. The antibody level was stable through week 12, showing a reduction in the following six months.

Impact of prior SARS-CoV-2 infection and COVID-19 vaccination on the subsequent incidence of COVID-19: a multicentre prospective cohort study among UK healthcare workers – the SIREN (Sarscov2 Immunity & REinfection EvaluatioN) study protocol

IntroductionUnderstanding the effectiveness and durability of protection against SARS-CoV-2 infection conferred by previous infection and COVID-19 is essential to inform ongoing management of the pandemic. This study aims to determine...

Post effects associated with SARS-CoV-2 vaccination among health care workers in Pakistan

The COVID-19 pandemic has witnessed the rapid development of vaccines produced simultaneously form various countries. However, these vaccines were shrouded by a set of myths ranging from serious effects to change of human DNA. Pakistan was one of the countries to start vaccination early and the front-line workers were first to be vaccinated. We undertook to study the vaccinated health care workers for the post effects of vaccines they received. The methodology adopted was through a structured questionnaire comprising 12 questions covering almost all the possible post effects. This was circulated among health care workers of Pak-Emirates Military hospital and Army Medical College/ National University of Medical Sciences, Rawalpindi, Pakistan. Fever was the most frequently encountered post effect, followed closely by pain at site of injection, headache and fatigue. There was a strong association between age and post effects of vaccination. No life threatening or serious side effects were experienced by health are workers indicating that benefits of vaccine outweigh its adverse effects especially with emergence of new variants. No participant required hospitalization following immunization. Therefore, vaccination against SARS-CoV-2 should be carried out on priority basis in order to avoid severe COVID-19 infection.&lt;br /&gt;&lt;br /&gt;

Significant Increase in Antibody Titers after the 3rd Booster Dose of the Pfizer-BioNTech mRNA COVID-19 Vaccine in Healthcare Workers in Greece.

The aim of our study was to assess the immunogenicity of the third dose of the BNT162b2 mRNA COVID-19 vaccine (Comirnaty) in a cohort of 129 health-care workers in Greece whose anti-S1 RBD IgG titers were monitored over the course of nine months. Titers were measured for each participant just before the third dose (nine months after the second dose) and also one month after the third dose. Of the 129 participants, 19 had been previously infected before starting the vaccination scheme. The SARS-CoV-2 IgG II Quant assay on the Architect System was employed to longitudinally assess the titers of IgG against the receptor-binding domain of the S1 subunit of the spike protein (anti-S1 RBD). Boosters raised Geometric Mean Concentrations (GMCs) by a factor of approximately 47 relative to levels at 9 months and by a factor of approximately 23 relative to levels at 6 months. The immune response one month after the third dose was significantly higher than the response achieved one month after the second dose (p = 0.008). In conclusion, our findings verify the potent immunogenicity elicited by the third dose in all age and prior COVID-19 status groups, suggesting that the timely administration of the third (booster) dose maximizes the immunogenic potential of the vaccine.

Antibody Response to COVID-19 Booster Vaccination in Healthcare Workers.

ObjectiveTo evaluate the mean increase of anti-S IgG antibody titer between the basal, pre-booster level to the titer assessed 14 days after the booster dose of BNT162b2.Patients and MethodsThe RENAISSANCE study is an observational, longitudinal, prospective, population-based study, conducted on healthcare workers of Niguarda Hospital in Milan, Italy who received a BNT162b2 booster dose at least 180 days after their second dose or after positivity for SARS-CoV-2 and accepted to take part in the study. The RENAISSANCE study was conducted from January 1, 2021 through December 28, 2021.Findings1,738 subjects were enrolled among healthcare workers registered for the booster administration at our hospital. Overall, 0.4% of subjects were seronegative at the pre-booster evaluation, and 1 subject had a titer equal to 50 AU/ml: none of the evaluated subjects was seronegative after the booster dose. Thus, the efficacy of the booster in our population was universal. Mean increase of pre- to post-booster titer was more significant in subjects who never had SARS-CoV-2 (44 times CI 95% 42-46) compared to those who had it, before (33 times, CI 95% 13-70) or after the first vaccination cycle (12 times, CI 95% 11-14). Differently from sex, age and pre-booster titers affected the post-booster antibody response. Nevertheless, the post-booster titer was very similar in all subgroups, and independent of a prior exposure to SARS-CoV-2, pre-booster titer, sex or age.ConclusionOur study shows a potent universal antibody response of the booster dose of BNT162b2, regardless of pre-booster vaccine seronegativity.

COVID-19 vaccination strategy for hospital staff in Germany: a cross-sectional study in March–April 2021

BackgroundSARS-CoV-2 vaccination for healthcare workers (HCWs) started in Germany in December 2020. Hospitals had little time to prepare a vaccination strategy.AimTo gather information on the initial vaccination strategy for HCWs from the infection control practitioners in Germany.MethodsA cross-sectional, ethically approved questionnaire was developed, formatted as an online survey and pre-tested. Infection control practitioners responsible for hygiene/infection prevention in 987 randomly selected German hospitals were invited to participate in the survey in March and April 2021. For statistical analysis, the hospitals were categorized into two groups based on bed capacity (<500 beds: small; ≥500 beds: large).FindingsOne hundred out of 987 (10%) infection control practitioners completed the survey. In 80% of the participating hospitals, HCW vaccination prioritization was based on recommendations of the German standing committee on vaccination (STIKO). Even so, only 54% prioritized the vaccination of HCWs with contact to vulnerable patients, thus deviating from STIKO recommendations. HCWs with a high personal health risk were prioritized for vaccination in 24% of the hospitals. Transferring unvaccinated HCWs to an area with less infection risk was considered by 2% of large and 12% of small hospitals.ConclusionVaccination prioritization differed across hospitals and deviated from STIKO recommendations. A pandemic preparedness concept should address the potential impact of divergent strategies compared to a common approach. In addition, further studies analysing the reasons why HCWs remain unvaccinated are needed to adopt effective strategies. This is especially important against the background of facility-based compulsory vaccination.

Breakthrough Infections of COVID-19 among Vaccinated Healthcare Workers in a Tertiary Care Hospital in Northern Kerala, India

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is rapidly spreading both in India and across the world and healthcare workers are at increased risk of contracting this infection due to their constant exposure status. This study aims to assess the breakthrough infections among vaccinated health care workers in a tertiary care centre. A cross sectional study was conducted for a period of one year among vaccinated healthcare workers who turned positive two weeks post complete vaccination. 82 (4.73%) out of 1732 vaccinated healthcare workers (2 doses) developed breakthrough COVID-19 infection of which 70.7% were females and the mean age was 35.5 years. 52.4% (n=43) were doctors, 30.5% nurses (n=25) and 15.9% were allied health professionals. 67 (81.7%) had mild symptoms, 10 (12.19%) were asymptomatic, 5 (6.09%) were hospitalised with none requiring ventilator support. 43.1% of infections occurred 6-9 months post vaccination. 23.7% acquired infection from fellow healthcare workers, 12.2% from household contacts, 46.3% from patients/bystanders, and 18.2% were from unknown sources. Proper understanding and analysis of the breakthrough COVID-19 infections can help in taking appropriate infection control practices as well as improving the overall health status of healthcare workers during this pandemic.

‘Leading from the front’ implementation increases the success of influenza vaccination drives among healthcare workers: a reanalysis of systematic review evidence using Intervention Component Analysis (ICA) and Qualitative Comparative Analysis (QCA)

BackgroundSeasonal influenza vaccination of healthcare workers (HCW) is widely recommended to protect staff and patients. A previous systematic review examined interventions to encourage uptake finding that hard mandates, such as loss of employment for non-vaccination, were more effective than soft mandates, such as signing a declination form, or other interventions such as incentives. Despite these overarching patterns the authors of the review concluded that ‘substantial heterogeneity’ remained requiring further analysis. This paper reanalyses the evidence using Intervention Component Analysis (ICA) and Qualitative Comparative Analysis (QCA) to examine whether the strategies used to implement interventions explain the residual heterogeneity.MethodsWe used ICA to extract implementation features and trialists’ reflections on what underpinned the success of the intervention they evaluated. The ICA findings then informed and structured two QCA analyses to systematically examine associations between implementation features and intervention outcomes. Analysis 1 examined hard mandate studies. Analysis 2 examined soft mandates and other interventions.ResultsIn Analysis 1 ICA revealed the significance of ‘leading from the front’ rather than ‘top-down’ implementation of hard mandates. Four key features underpinned this: providing education prior to implementation; two-way engagement so HCW can voice concerns prior to implementation; previous use of other strategies so that institutions ‘don’t-go-in-cold’ with hard-mandates; and support from institutional leadership. QCA revealed that either of two configurations were associated with greater success of hard mandates. The first involves two-way engagement, leadership support and a ‘don’t-go-in-cold’ approach. The second involves leadership support, education and a ‘don’t-go-in-cold’ approach. Reapplying the ‘leading from the front’ theory in Analysis 2 revealed similar patterns.ConclusionsRegardless of intervention type a ‘leading from the front’ approach to implementation will likely enhance intervention success. While the results pertain to flu vaccination among HCWs, the components identified here may be relevant to public health campaigns regarding COVID-19 vaccination.

Impact of SARS-CoV-2 vaccination in healthcare workers in a network of clinics in Latin America

ObjectivesHealthcare workers (HCWs) have been severely affected in terms of both morbidity and mortality since the beginning of the COVID-19 pandemic. During the first few months of 2021, Colombia experienced a surge in positive cases. This study aimed to evaluate the effect of vaccination on the incidence of new positive cases in HCWs. DesignThis was a retrospective cohort study of frontline employees in a network of clinics in Colombia, who were prioritized for COVID-19 vaccination from February to March 2021. ResultsOur findings were consistent with recent reports. During early 2020, the incidence of HCWs positively diagnosed with COVID-19 in Colombia was higher than that for the general population. With the start of the national vaccination program, the incidence among HCWs decreased from April 2021, while that for the general population remained relatively unchanged. Our study identified lower infection rates among HCWs during April (odds ratio [OR], 0.72 [95% CI 0.58–0.90]; p < 0.01) and May (odds ratio [OR], 0.25 [95% CI 0.18–0.36]; p < 0.01). ConclusionsCOVID-19 vaccination rollout in Colombia during early 2021 led to a decrease in the incidence of new positive cases among HCWs, in contrast to a continuing surge in the general population. Our findings suggested that COVID-19 vaccination provided adequate immunity, which guaranteed protection to HCWs.

Adverse events after BNT162b2 mRNA COVID-19 vaccination in health care workers and medical students in Japan

To control the coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the promotion of vaccination is important. However, adverse reactions following vaccination remain a concern. To investigate adverse events in the vaccinated Japanese population, we conducted a survey-based study among health care workers, including medical doctors and nurses; other medical staff; and medical university faculty, staff, and students in a single medical school and affiliated hospital in Japan. In addition, we analyzed the association of different adverse events with individual factors (e.g., age, sex) by performing network analysis. While young age and female sex are often considered risk factors for more severe adverse events, the regression models showed neither age nor sex was associated with local injection-site reactions after the second dose in this study. In contrast to local reactions, systemic adverse events were associated with young age and female sex. However, myalgia was unique in that it was not associated with younger age even though the network analysis showed that myalgia was consistently related to arthralgia and belonged to the group of systemic events after both the first and second vaccine doses. Further study is needed to ensure safe and effective vaccination to aid in controlling the COVID-19 pandemic.

COVID-19 Vaccination in Health Care Workers in Italy: A Literature Review and a Report from a Comprehensive Cancer Center.

The coronavirus disease 2019 pandemic still represents a global public health emergency, despite the availability of different types of vaccines that reduced the number of severe cases, the hospitalization rate and mortality. The Italian Vaccine Distribution Plan identified healthcare workers (HCWs) as the top-priority category to receive access to a vaccine and different studies on HCWs have been implemented to clarify the duration and kinetics of antibody response. The aim of this paper is to perform a literature review across a total of 44 studies of the serologic response to COVID-19 vaccines in HCWs in Italy and to report the results obtained in a prospective longitudinal study implemented at the Fondazione IRCCS Istituto Nazionale Tumori (INT) of Milan on 1565 HCWs. At INT we found that 99.81% of the HCWs developed an antibody response one month after the second dose. About six months after the first serology evaluation, 100% of the HCWs were still positive to the antibody, although we observed a significant decrease in its levels. Overall, our literature review results highlight a robust antibody response in most of the HCWs after the second vaccination dose. These figures are also confirmed in our institutional setting seven months after the completion of the cycle of second doses of vaccination.

Sex differences in B cell frequencies and antibody responses following influenza vaccination in healthcare workers during the 2019–2020 season

Abstract Annual influenza vaccination for healthcare workers (HCWs) is required at Johns Hopkins to reduce influenza spread in healthcare facilities. We conducted a clinical study to evaluate sex differences in virus-specific antibody-producing B cells (i.e., plasmablasts) following receipt of the seasonal influenza vaccine in a highly vaccinated population of healthcare workers. To understand sex differences in immune responses to the influenza vaccine in the HCWs, 83 participants consented to blood draws at baseline and 75 participants returned for the 7- and 28-days post-vaccination survey and blood draw. Participants received their annual quadrivalent influenza vaccine (QIV). Influenza A specific plasmablasts were quantified at baseline and day 7 post-vaccination. Males had a significantly greater percentage of influenza-specific plasmablasts than females after vaccination (p&amp;lt;0.0003) Plasma collected at baseline and at day 28 post-vaccination was used to measure neutralizing antibody (nAb) titers against H1N1 and H3N2 vaccine viruses. Neutralizing antibody responses against either the H1N1 and H3N2 viruses increase after vaccination to the same degree in both males and females. The proportion of plasmablasts at day 7 was significantly associated with the vaccine-induced fold rise in nAb. This relationship differed by sex, whereby for a given proportion of plasmablasts, females tended to mount a greater fold-rise in nAb than males. These data suggest that despite having potentially fewer plasmablasts after vaccination, females mount an antiviral antibody response to the influenza vaccine viruses equivalent to males. Identification of transcriptional differences in plasmablasts from male and female HCWs is ongoing.

Prevalence of COVID-19 Vaccine Side Effects among Early-Vaccinated Healthcare Workers in Eastern Ethiopia.

The Ministry of Health of Ethiopia launched the COVID-19 vaccination campaign in March 2021, with frontline healthcare workers as first-round recipients and a goal of vaccinating 20% of the population by the end of 2021. The study aims to estimate the prevalence of COVID-19 vaccination side effects among early vaccinated healthcare workers in Adama hospital medical college. A cross-sectional study was carried out between March and June 2021, following the vaccination of COVID-19 vaccine among healthcare workers in Adama hospital medical college. The study used a structured self-administered questionnaire and additional telephone surveys on items covering the participants' demographic data, local and systemic manifestations after vaccination. A total of 540 health care workers and supportive staff were enrolled in this study. The overall any-symptom report after the first dose of ChAdOx1 nCoV- 19 vaccine was 84.3%. The majority (39.6%) of participants had both systemic and local symptoms and 25.7% had only local and 18.9% had only systemic symptoms. Injection site pain was the most prevalent side effect symptom (64.1%), followed by fatigue (35.7%), headache (28.9%), joint pain (26.5%), and muscle pain (21.5%). Vaccine side effects were common and found to be well-tolerated among the recipients of the first dose of ChAdOx1 nCoV-19 at Adama hospital medical college healthcare workers. The side effects were mainly mild to moderate. More side-effect profiles should be studied and disseminated to detect rare adverse reactions.

Age and sex associations of SARS-CoV-2 antibody responses post BNT162b2 vaccination in healthcare workers: A mixed effects model across two vaccination periods.

This study aimed to examine the associations with epidemiological, behavioral and clinical parameters of IgG antibody responses against the spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after immunization with two doses of the BNT162b2 vaccine in a cohort of healthcare workers (HCWs, n = 439) in Greece. We used a mixed effects model to investigate the potential associations of antibody levels one and three months after vaccination and examined by bootstrapping t-tests the putative effects of gender and age for each period. We also employed exact tests of independence in R × C contingency tables to explore associations between behavioral and gender variables with vaccinations side effects. We found significant differences between males and females as well as between subjects in the youngest (21–30 years) and the older age groups in both study periods. We also detected a decrease in titers with age and time. Males had steeper elimination rates across the age span in both periods, in contrast to females who exhibited a softer elimination titer rate with age in the first period and almost constant titers in the second. Concerning side effects, we found a significant association between pain at the injection site and female sex. Hence, our real-world data analyses revealed potentially important clues into the associations of antibody responses to SARS-CoV-2 spike. We discuss the importance of these findings in view of current mass vaccination perspectives and provide useful clues for the design and optimal timing of booster doses for COVID-19.

The impact of COVID-19 on use of maternal and reproductive health services and maternal and perinatal mortality

South Africa experienced two waves of COVID-19 infection in the financial year 2020/21. This study examines the impact of these waves on maternal and perinatal mortality and their effect on the use of and access to maternal and reproductive health services. Data from the District Health Information System on maternal and perinatal deaths, births, antenatal visits, and use of contraceptive termination of pregnancy services were used, and the 2020/21 and 2019/20 financial years were compared in order to formulate national and provincial perspectives. Data on visits for initiating antenatal care, births, contraceptive prescriptions and termination-of-pregnancy services were used to assess utilisation of maternal and reproductive health services respectively; and the number and rates of maternal and perinatal deaths were examined to assess impact. A second descriptive analysis of pregnant women who had delivered after having contracted COVID-19 was performed using a separate database set up by the National Department of Health/South African Medical Research Council/University of Pretoria (NDoH/ SAMRC/UP), specifically to monitor the effects of COVID-19). The data suggest that there was a marked increase (of 40%) in maternal deaths (p&lt;0.00001), 10% in stillbirths (p&lt;0.00001), and 3% in (p=0.31) neonatal deaths when compared with the same period in 2019/20. There was a mean 28% increase in the institutional maternal mortality ratio in all provinces during the second wave compared with the first wave (p&lt;0.0001), except in the Western Cape which had a decrease of 1%. Data from the National Institute for Communicable Diseases showed that the case fatality rate for pregnant women with COVID-19 was high (4.5%), as was the perinatal mortality rate (70.6 per 1 000 births), while the institutional maternal mortality ratio for South Africa was 16.94/100 000 live births. An increase of 3.6% in in-facility births in 2020/21 compared with 2019/20 was observed, with increased movement of pregnant women to the more rural provinces and districts for delivery. Antenatal care services were maintained overall, but use of reproductive health services declined (contraceptive prescriptions by 5%, and termination of pregnancy by 17% overall). The effect of the COVID-19 epidemic on pregnant women and its collateral damage is severe. Strengthening the health system to maintain essential services during a pandemic and vaccination of healthcare workers and pregnant women are key to reducing maternal and perinatal mortality.

Early and Longitudinal Humoral Response to the SARS-CoV-2 mRNA BNT162b2 Vaccine in Healthcare Workers: Significance of BMI, Adipose Tissue and Muscle Mass on Long-Lasting Post-Vaccinal Immunity.

Background: This study aimed to investigate the early and longitudinal humoral response in Healthcare Workers (HCWs) after two doses of the BNT162b2 vaccine and to assess the association between metabolic and anthropometric parameters and the humoral response after vaccination. Methods: The study included 243 fully vaccinated HCWs: 25.50% previously infected with SARS-CoV-2 (with prior history of COVID-19—PH) and 74.40%—uninfected, seronegative before the first vaccination (with no prior history of COVID-19—NPH). IgG antibodies were measured, and sera were collected: prior to the vaccination, 21 days after the first dose, and 14 days and 8 months after the second dose. Results: 21 days after the first dose, 90.95% of individuals were seropositive; 14 days after the second dose, persistent immunity was observed in 99.18% HCWs, 8 months after complete vaccination—in 61.73%. Statistical analysis revealed that HCWs with PH had a greater chance of maintaining a humoral response beyond eight months after vaccination. Increased muscle mass, decreased fat mass, and younger age may positively affect long-term immunity. Smokers have a reduced chance of developing immunity compared to non-smokers. Conclusions: Fully vaccinated HCWs with PH are more likely to be seropositive than fully inoculated volunteers with NPH.

Long-Lasting T Cell Responses in BNT162b2 COVID-19 mRNA Vaccinees and COVID-19 Convalescent Patients.

The emergence of novel variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has made it more difficult to prevent the virus from spreading despite available vaccines. Reports of breakthrough infections and decreased capacity of antibodies to neutralize variants raise the question whether current vaccines can still protect against COVID-19 disease. We studied the dynamics and persistence of T cell responses using activation induced marker (AIM) assay and Th1 type cytokine production in peripheral blood mononuclear cells obtained from BNT162b2 COVID-19 mRNA vaccinated health care workers and COVID-19 patients. We demonstrate that equally high T cell responses following vaccination and infection persist at least for 6 months against Alpha, Beta, Gamma, and Delta variants despite the decline in antibody levels.

Comparison of the Immunogenicity and Protective Efficacy of Various SARS-CoV-2 Vaccines among Healthcare Workers: Are Our White Coat Armies Protected?

Background: The effective immunization of healthcare workers (HCWs) plays a vital role in preventing the spread of SARS-CoV-2 infection during the coronavirus disease 2019 (COVID-19) pandemic. There is limited data on the immune response to vaccination among HCWs. We aim to determine seroprevalence rates and neutralizing IgG antibody response to various immunizations among HCWs. Methods: This study was conducted between July and September 2021, in which blood samples were obtained from HCWs and SARS-CoV-2 IgG neutralizing antibodies were measured. Data regarding vaccination status with Pfizer/BioNTech, Sinopharm, or AstraZeneca vaccines, occupation, and prior COVID-19 infection were analyzed. Results: COVID-19 infection post-vaccination was associated with higher mean antibody titers, regardless of vaccine type. Pfizer/BioNTech vaccination produced higher mean antibody titers for HCWs with prior COVID-19 infection (p < 0.00001) than other types of vaccines. Although 96% of HCWs were vaccinated, 3% were seronegative. For HCWs who were seropositive, there were no significant differences between the mean antibody titers when comparing occupations and blood indices. Conclusion: Awareness of the immunity status of HCWs is key to protecting this important group against SARS-CoV-2, especially those without prior COVID-19 infection. Further public health efforts regarding booster vaccination for HCWs are crucial to provide necessary antibody protection.

Higher Antibody Concentrations in U.S. Health Care Workers Associated with Greater Reactogenicity Post-Vaccination.

Multiple factors may be associated with immune responses to SARS-CoV-2 vaccines. Factors potentially related to magnitude and durability of response include age, time, and vaccine reactogenicity. This study analyzed SARS-CoV-2 IgG spike antibody responses following the second dose of vaccine in healthcare workers (HCWs). Data were collected from participants enrolled in a longitudinal SARS-CoV-2 serology study over a 12-month period. Participants completed a survey documenting symptoms post-vaccination. Serum specimens were tested for SARS-CoV-2 IgG antibodies using the Abbott Architect AdvisdeDx SARS-CoV-2 IgGII assay. Antibody levels were compared against time from second vaccine dose, and symptoms following vaccination. Altogether, 335 women (86.6%) and 52 men (13.4%) participated. Median age was 37 years (IQR 30-43). Overall median antibody level was 2150.80 [1246.12, 3556.98] AU/mL (IQR). Age was not associated with antibody concentration (p-value = 0.10). Higher antibody responses (2253 AU/mL vs. 1506 AU/mL; p = 0.008) were found in HCWs with one or more symptoms after the second dose of the vaccine (n = 311). Antibody responses persisted throughout the study period post-vaccination; statistically significant decreases in antibody responses were observed over time (p < 0.001). Higher antibody response was associated with reactogenicity post-vaccine. Age and sex were not associated with higher antibody responses.

Persistence of SARS-CoV-2 Antibodies in Vaccinated Health Care Workers Analyzed by Coronavirus Antigen Microarray.

Recent studies provide conflicting evidence on the persistence of SARS-CoV-2 immunity induced by mRNA vaccines. Here, we aim to quantify the persistence of humoral immunity following vaccination using a coronavirus antigen microarray that includes 10 SARS-CoV-2 antigens. In a prospective longitudinal cohort of 240 healthcare workers, composite SARS-CoV-2 IgG antibody levels did not wane significantly over a 6-month study period. In the subset of the study population previously exposed to SARS-CoV-2 based on seropositivity for nucleocapsid antibodies, higher composite anti-spike IgG levels were measured before the vaccine but no significant difference from unexposed individuals was observed at 6 months. Age, vaccine type, or worker role did not significantly impact composite IgG levels, although non-significant trends towards lower antibody levels in older participants and higher antibody levels with Moderna vaccine were observed at 6 months. A small subset of our cohort were classified as having waning antibody titers at 6 months, and these individuals were less likely to work in patient care roles and more likely to have prior exposure to SARS-CoV-2.