SARS-CoV-2-Specific Neutralizing Antibody Responses in Norwegian Health Care Workers After the First Wave of COVID-19 Pandemic: A Prospective Cohort Study

Hospitalisations and humoral COVID-19 vaccine response in vaccinated rituximab-treated multiple sclerosis patients

BACKGROUND

Patients with multiple sclerosis (MS) treated with anti-CD20 therapies such as rituximab may have increased risk of severe COVID-19 disease. Vaccination induces protective immunity, but humoral vaccine response is known to be attenuated in rituximab-treated MS-patients-patients, which has indicated a need for real world data on severe morbidity and mortality from COVID-19 after vaccination.

METHODS

Rituximab-treated patients treated at Haukeland University Hospital were identified through the National MS Registry and invited to participate in the study by giving a consent and providing a blood sample 3 weeks or later after ordinary COVID-19- vaccination, i.e. 2 doses given with a standard interval of 3 weeks. Blood samples were analysed with Enzyme-Linked Immunosorbent assay (ELISA) to evaluate humoral vaccine response with screening test against receptor-binding domain (RBD) and confirmatory Spike IgG-specific ELISA. A haemagglutination test (HAT) was performed as a marker of neutralizing antibodies. Patient serum concentration of rituximab were quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS). Registry data from the Norwegian MS registry and information on hospitalization from patient records were collected and linked to laboratory results.

RESULTS

111 patients were included in the study. A total of 7 (6.3%) were hospitalized due to COVID-19 disease during the observation period. No patient was admitted to ICU and there were no deaths. 34.2% did not have detectable titre of SARS CoV-2 Spike IgG antibodies, 72.1% did not have a detectable titre of SARS CoV-2 RBD antibodies, and 88.2% did not have a detectable HAT titre. There was a correlation between hospitalisation and the absence of SARS CoV-2 Spike IgG antibody titre, and between hospitalisation and MS disease duration, as well as between spike IgG antibody titre and CD19 B-cell count, time since last rituximab infusion, cumulative rituximab treatment time and total IgG level in the patients.

CONCLUSION

A substantial proportion of rituximab-treated MS-patients-patients did not have detectable humoral vaccine responses after 2 doses of COVID-19 vaccination. Despite this, the cumulative percentage of patients hospitalized with COVID-19 disease throughout the observation period of 22 months was low, and no patients required ICU treatment. The results support that vaccinated MS-patients treated with rituximab have a protective effect against serious Covid-19 infection.

The Anti-SARS-CoV-2 IgG1 and IgG3 Antibody Isotypes with Limited Neutralizing Capacity against Omicron Elicited in a Latin Population a Switch toward IgG4 after Multiple Doses with the mRNA Pfizer-BioNTech Vaccine

The aim of this study was to analyze the profiles of IgG subclasses in COVID-19 convalescent Puerto Rican subjects and compare these profiles with those of non-infected immunocompetent or immunocompromised subjects that received two or more doses of an mRNA vaccine. The most notable findings from this study are as follows: (1) Convalescent subjects that were not hospitalized developed high and long-lasting antibody responses. (2) Both IgG1 and IgG3 subclasses were more prevalent in the SARS-CoV-2-infected population, whereas IgG1 was more prevalent after vaccination. (3) Individuals that were infected and then later received two doses of an mRNA vaccine exhibited a more robust neutralizing capacity against Omicron than those that were never infected and received two doses of an mRNA vaccine. (4) A class switch toward the "anti-inflammatory" antibody isotype IgG4 was induced a few weeks after the third dose, which peaked abruptly and remained at high levels for a long period. Moreover, the high levels of IgG4 were concurrent with high neutralizing percentages against various VOCs including Omicron. (5) Subjects with IBD also produced IgG4 antibodies after the third dose, although these antibody levels had a limited effect on the neutralizing capacity. Knowing that the mRNA vaccines do not prevent infections, the Omicron subvariants have been shown to be less pathogenic, and IgG4 levels have been associated with immunotolerance and numerous negative effects, the recommendations for the successive administration of booster vaccinations to people should be revised.

From rejection to the Nobel Prize: Karikó and Weissman's pioneering work on mRNA vaccines, and the need for diversity and inclusion in translational immunology

Katalin Karikó and Drew Weissman were given the 2023 Nobel Prize in Physiology or Medicine for their findings of nucleoside base modifications that lead to the development of effective mRNA vaccines against COVID-19. This was a remarkable achievement, given that their initial manuscript was rejected by Nature and Science in 2005. The development of mRNA vaccines lagged for more than a decade for several reasons, including the lack of funding, the perceived risks of the technology, and the scepticism of many scientists. Furthermore, Karikó and Weissman's study appeared to be technical and difficult to understand. The COVID-19 pandemic, on the other hand, has shown the importance of mRNA vaccine technology. COVID-19 mRNA vaccines have been highly effective in preventing serious illness, hospitalization, and death. The Nobel Prize for Karikó and Weissman highlights the importance of perseverance, diversity, and inclusion in translational immunology. We need to build a more inclusive scientific community, where scientists from all backgrounds are supported and their work is valued. This will result in more scientific breakthroughs and better healthcare for everyone.

SARS-CoV-2 specific immune responses in overweight and obese COVID-19 patients

Obesity is a known risk factor for severe respiratory tract infections. In this prospective study, we assessed the impact of being obese or overweight on longitudinal SARS-CoV-2 humoral and cellular responses up to 18 months after infection. 274 patients provided blood samples at regular time intervals up to 18 months including obese (BMI ≥30, n=32), overweight (BMI 25-29.9, n=103) and normal body weight (BMI 18.5-24.9, n=134) SARS-CoV-2 patients. We determined SARS-CoV-2 spike-specific IgG, IgA, IgM levels by ELISA and neutralising antibody titres by neutralisation assay. RBD- and spike-specific memory B cells were investigated by ELISpot, spike- and non-spike-specific IFN-γ, IL-2 and IFN-γ/IL-2 secreting T cells by FluoroSpot and T cell receptor (TCR) sequencing was performed. Higher BMI correlated with increased COVID-19 severity. Humoral and cellular responses were stronger in overweight and obese patients than normal weight patients and associated with higher spike-specific IgG binding titres relative to neutralising antibody titres. Linear regression models demonstrated that BMI, age and COVID-19 severity correlated independently with higher SARS-CoV-2 immune responses. We found an increased proportion of unique SARS-CoV-2 specific T cell clonotypes after infection in overweight and obese patients. COVID-19 vaccination boosted humoral and cellular responses irrespective of BMI, although stronger immune boosting was observed in normal weight patients. Overall, our results highlight more severe disease and an over-reactivity of the immune system in overweight and obese patients after SARS-CoV-2 infection, underscoring the importance of recognizing overweight/obese individuals as a risk group for prioritisation for COVID-19 vaccination.

Vaccination prevents severe COVID-19 outcome in patients with neutralizing type 1 interferon autoantibodies

A hallmark of patients with autoimmune polyendocrine syndrome type 1 (APS-1) is serological neutralizing autoantibodies against type 1 interferons (IFN-I). The presence of these antibodies has been associated with severe course of COVID-19. The aims of this study were to investigate SARS-CoV-2 vaccine tolerability and immune responses in a large cohort of patients with APS-1 (N = 33) and how these vaccinated patients coped with subsequent infections. We report that adult patients with APS-1 were able to mount adequate SARS-CoV-2 spike-specific antibody responses after vaccination and observed no signs of decreased tolerability. Compared with age- and gender-matched healthy controls, patients with APS-1 had considerably lower peak antibody responses resembling elderly persons, but antibody decline was more rapid in the elderly. We demonstrate that vaccination protected patients with APS-1 from severe illness when infected with SARS-CoV-2 virus, overriding the systemic danger of IFN-I autoantibodies observed in previous studies.

Risk assessment and antibody responses to SARS-CoV-2 in healthcare workers

Background

Preventing infection in healthcare workers (HCWs) is crucial for protecting healthcare systems during the COVID-19 pandemic. Here, we investigated the seroepidemiology of SARS-CoV-2 in HCWs in Norway with low-transmission settings.

Methods

From March 2020, we recruited HCWs at four medical centres. We determined infection by SARS-CoV-2 RT-PCR and serological testing and evaluated the association between infection and exposure variables, comparing our findings with global data in a meta-analysis. Anti-spike IgG antibodies were measured after infection and/or vaccination in a longitudinal cohort until June 2021.

Results

We identified a prevalence of 10.5% (95% confidence interval, CI: 8.8-12.3) in 2020 and an incidence rate of 15.0 cases per 100 person-years (95% CI: 12.5-17.8) among 1,214 HCWs with 848 person-years of follow-up time. Following infection, HCWs (n = 63) mounted durable anti-spike IgG antibodies with a half-life of 4.3 months since their seropositivity. HCWs infected with SARS-CoV-2 in 2020 (n = 46) had higher anti-spike IgG titres than naive HCWs (n = 186) throughout the 5 months after vaccination with BNT162b2 and/or ChAdOx1-S COVID-19 vaccines in 2021. In a meta-analysis including 20 studies, the odds ratio (OR) for SARS-CoV-2 seropositivity was significantly higher with household contact (OR 12.6; 95% CI: 4.5-35.1) and occupational exposure (OR 2.2; 95% CI: 1.4-3.2).

Conclusion

We found high and modest risks of SARS-CoV-2 infection with household and occupational exposure, respectively, in HCWs, suggesting the need to strengthen infection prevention strategies within households and medical centres. Infection generated long-lasting antibodies in most HCWs; therefore, we support delaying COVID-19 vaccination in primed HCWs, prioritising the non-infected high-risk HCWs amid vaccine shortage.

Durable immune responses after BNT162b2 vaccination in home-dwelling old adults

Objectives

Elderly are an understudied, high-risk group vulnerable to severe COVID-19. We comprehensively analyzed the durability of humoral and cellular immune responses after BNT162b2 vaccination and SARS-CoV-2 infection in elderly and younger adults.

Methods

Home-dwelling old (n = 100, median 86 years) and younger adults (n = 449, median 38 years) were vaccinated with two doses of BNT162b2 vaccine at 3-week intervals and followed for 9-months. Vaccine-induced responses were compared to home-isolated COVID-19 patients (n = 183, median 47 years). Our analysis included neutralizing antibodies, spike-specific IgG, memory B-cells, IFN-γ and IL-2 secreting T-cells and sequencing of the T-cell receptor (TCR) repertoire.

Results

Spike-specific breadth and depth of the CD4⁺ and CD8⁺ TCR repertoires were significantly lower in the elderly after one and two vaccinations. Both vaccinations boosted IFN-γ and IL-2 secreting spike-specific T-cells responses, with 96 % of the elderly and 100 % of the younger adults responding after the second dose, although responses were not maintained at 9-months. In contrast, T-cell responses persisted up to 12-months in infected patients. Spike-specific memory B-cells were induced after the first dose in 87 % of the younger adults compared to 38 % of the elderly, which increased to 83 % after the second dose. Memory B-cells were maintained at 9-months post-vaccination in both vaccination groups. Neutralizing antibody titers were estimated to last for 1-year in younger adults but only 6-months in the older vaccinees. Interestingly, infected older patients (n = 15, median 75 years) had more durable neutralizing titers estimated to last 14-months, 8-months longer than the older vaccinees.

Conclusions

Vaccine-induced spike-specific IgG and neutralizing antibodies were consistently lower in the older than younger vaccinees. Overall, our data provide valuable insights into the kinetics of the humoral and cellular immune response in the elderly after SARS-CoV-2 vaccination or infection, highlighting the need for two doses, which can guide future vaccine design.Clinical trials.gov; NCT04706390.

Kinetics of SARS-CoV-2 IgM and IgG Antibodies 3 Months after COVID-19 Onset in Moroccan Patients

Coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) poses serious global public health problems. Characterization of the immune response, particularly antibodies to SARS-CoV-2, is important for establishing vaccine strategies. The purpose of this study was to evaluate longitudinally the kinetics of anti-SARS-CoV-2 antibodies against spike protein (S1) for up to 3 months in a cohort of 169 COVID-19 patients. We enrolled COVID-19 patients at two regional hospitals in Casablanca, Morocco, between March and September 2021. Blood samples were collected and N-specific IgM and S-specific IgG levels were measured by a commercial Euroimmun ELISA. IgM antibodies were assessed 2-5 (D00), 9-12 (D07), 17-20 (D15), and 32-37 (D30) days after symptom onset; IgG antibodies were assessed at these time points plus 60 (D60) and 90 (D90) days after symptom onset. We found that at 3 months after symptom onset, 79% of patients had detectable SARS-CoV-2-specific IgG antibodies, whereas their IgM seropositivity was 19% by 1 month after symptom onset. The IgM level decreased to 0.34 (interquartile range [IQR] 0.19-0.92) at 1 month after symptom onset, whereas the IgG level peaked at D30 (3.10; IQR 1.83-5.64) and remained almost stable at D90 (2.95; IQR 1.52-5.19). IgG levels were significantly higher in patients older than 50 years than in those younger than 50 at all follow-up time points (P < 0.05). Statistical analysis showed no significant difference in median anti-S1 antibody levels among infected patients based on gender or comorbidities. This study provides information on the longevity of anti-SARS-CoV-2 IgM and IgG antibodies in COVID-19 patients.

SARS CoV-2 Infection among Health Care Workers from Different Health Care Facilities in Western Norway: A Prospective, Cross-Sectional Study

Background: Comparative data on COVID-19 among health care workers (HCWs) in different health care settings are scarce. This study investigated the rates of previous COVID-19 among HCWs in nursing homes, hospitals and a municipal emergency room (ER). Methods: We prospectively included 747 HCWs: 313 from nursing homes, 394 from hospitals and 40 from the ER. The diagnosis of COVID-19 was based on serological evidence of SARS-CoV-2 antibody positivity and self-reported RT-PCR positivity prior to inclusion. Information regarding age, sex and exposure to SARS-CoV-2 infection was collected. Results: A total of 4% (11/313) of nursing home HCWs and 6% (28/434) of HCWs in hospitals/the ER tested positive by serology and/or RT-PCR (p = 0.095). Fewer HCWs in nursing homes had occupational exposure to SARS-CoV-2 compared to those in hospitals/the ER (16% vs. 48%, p < 0, 001), but nursing homes had a higher proportion of HCWs with occupational exposure using partial/no PPE (56% vs. 19%, p < 0.001). Nevertheless, no significant differences in the risk for COVID-19 were found in relation to the rate of occupational exposure (p = 0.755) or use of inadequate PPE (p = 0.631). Conclusions: Despite a small sample size, the risk for COVID-19 among HCWs did not appear to be related to the type of health care facility, rates of occupational exposure or use of PPE.

The Performances of Three Commercially Available Assays for the Detection of SARS-CoV-2 Antibodies at Different Time Points Following SARS-CoV-2 Infection

The aim of this study was to evaluate the performances of three commercially available antibody assays for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies at different time points following SARS-CoV-2 infection. Sera from 536 cases, including 207 SARS-CoV-2 PCR positive, were tested for SARS-CoV-2 antibodies with the Wantai receptor binding domain (RBD) total antibody assay, Liaison S1/S2 IgG assay and Alinity i nucleocapsid IgG assay and compared to a two-step reference ELISA (SARS-CoV-2 RBD IgG and SARS-CoV-2 spike IgG). Diagnostic sensitivity, specificity, predictive values and Cohen's kappa were calculated for the commercial assays. The assay's sensitivities varied greatly, from 68.7% to 95.3%, but the specificities remained high (96.9-99.1%). The three tests showed good performances in sera sampled 31 to 60 days after PCR positivity compared to the reference ELISA. The total antibody test performed better than the IgG tests the first 30 days and the nucleocapsid IgG test showed reduced sensitivity two months or more after PCR positivity. Hence, the test performances at different time points should be taken into consideration in clinical practice and epidemiological studies. Spike or RBD IgG tests are preferable in sera sampled more than two months following SARS-CoV-2 infection.

Symptom Burden and Immune Dynamics 6 to 18 Months Following Mild Severe Acute Respiratory Syndrome Coronavirus 2 Infection (SARS-CoV-2): A Case-control Study

BACKGROUND

The burden and duration of persistent symptoms after nonsevere coronavirus disease 2019 (COVID-19) remains uncertain. This study aimed to assess postinfection symptom trajectories in home-isolated COVID-19 cases compared with age- and time- matched seronegative controls, and investigate immunological correlates of long COVID.

METHODS

A prospective case-control study included home-isolated COVID-19 cases between February 28 and April 4, 2020, and followed for 12 (n = 233) to 18 (n = 149) months, and 189 age-matched severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-naive controls. We collected clinical data at baseline, 6, 12, and 18 months postinfection, and blood samples at 2, 4, 6, and 12 months for analysis of SARS-CoV-2-specific humoral and cellular responses.

RESULTS

Overall, 46% (108/233) had persisting symptoms 12 months after COVID-19. Compared with controls, adult cases had a high risk of fatigue (27% excess risk, sex, and comorbidity adjusted odds ratio [aOR] 5.86; 95% confidence interval [CI], 3.27-10.5), memory problems (21% excess risk; aOR 7.42; CI, 3.51-15.67), concentration problems (20% excess risk; aOR 8.88; 95% CI, 3.88-20.35), and dyspnea (10% excess risk; aOR 2.66; 95% CI, 1.22-5.79). The prevalence of memory problems increased overall from 6 to 18 months (excess risk 11.5%; 95% CI, 1.5-21.5; P = .024) and among women (excess risk 18.7%; 95% CI, 4.4-32.9; P = .010). Longitudinal spike immunoglobulin G was significantly associated with dyspnea at 12 months. The spike-specific clonal CD4+ T-cell receptor β depth was significantly associated with both dyspnea and number of symptoms at 12 months.

CONCLUSIONS

This study documents a high burden of persisting symptoms after mild COVID-19 and suggests that infection induced SARS-CoV-2-specific immune responses may influence long-term symptoms.

SARS-CoV-2 RBD-specific and NP-specific antibody response of healthcare workers in the westernmost Austrian state Vorarlberg: a prospective cohort study

OBJECTIVES

Austria, and particularly its westernmost federal state Vorarlberg, developed an extremely high incidence rate during the COVID-19 pandemic. Healthcare workers (HCWs) worldwide are known to have an increased risk of contracting the disease within the working environment and, therefore, the seroprevalence in this population is of particular interest. We thus aimed to analyse SARS-CoV-2-specific antibody dynamics in Vorarlberg HCWs.

DESIGN

Prospective cohort study of HCWs including testing at three different time points for the prevalence of anti-SARS-CoV-2 IgG antibodies specific for nucleocapsid protein (NP) and receptor-binding domain (RBD).

SETTING

All five state hospitals of Vorarlberg.

PARTICIPANTS

A total of 395 HCWs, enrolled in June 2020 (time point 1 (t₁)), 2 months after the end of the first wave, retested between October and November at the beginning of the second wave (time point 2 (t₂)) and again at the downturn of the second wave in January 2021 (time point 3 (t₃)).

MAIN OUTCOMES

We assessed weak and strong seropositivity and associated factors, including demographic and clinical characteristics, symptoms consistent with COVID-19 infection, infections verified by reverse transcription PCR (RT-PCR) and vaccinations.

RESULTS

At t₁, 3% of HCWs showed strong IgG-specific responses to either NP or RBD. At t₂, the rate had increased to 4%, and at t₃ to 14%. A strong response was found to be stable for up to 10 months. Overall, only 55% of seropositive specimen had antibodies against both antigens RBD and NP; 29% had only RBD-specific and 16% only NP-specific antibodies. Compared with the number of infections found by RT-PCR, the number of HCWs being seropositive was 38% higher.

CONCLUSION AND RELEVANCE

Serological testing based on only one antigen implicates the risk of missing infections; thus, the set of antigens should be broadened in the future. The seroprevalence among participating HCWs was comparable to the general population in Austria. Nevertheless, in view of undetected infections, monitoring and surveillance should be reconsidered.

COVID-19 Vaccines and Public Anxiety: Antibody Tests May Be Widely Accepted

Background

More than 200 countries are experiencing the coronavirus disease (COVID-19) pandemic. COVID-19 vaccination strategies have been implemented worldwide, and repeat COVID-19 outbreaks have been seen. The purpose of this study was to investigate the impact of COVID-19 vaccination on the reduction of perceived anxiety and the association between public anxiety and antibody testing intention during the COVID-19 pandemic.

Methods

Chinese adults aged 18 and over were surveyed using an anonymous online questionnaire in April and May 2021. The questionnaire collected sociodemographic characteristics, vaccination characteristics, perceived anxiety due to COVID-19, and attitudes toward future antibody testing after COVID-19 vaccination. Perceived anxiety was assessed on a visual analog scale (VAS). Multivariate logistic regression analysis was used to determine the factors influencing future antibody detection.

Results

A total of 3,233 people were investigated, 3,209 valid questionnaires were collected, and the response rate was 99.3%. Of the 3,209 respondents, 2,047 were vaccinated, and 1,162 were unvaccinated. There was a significant difference in anxiety levels between vaccinated and unvaccinated respondents (24.9±25.4 vs. 50.0±33.1, respectively). With the local spread of COVID-19 in mainland China, the public anxiety VAS scores increased by 15.4±25.6 (SMD=120%) and 33.8±31.7 (SMD=49%) among vaccinated and unvaccinated respondents, respectively. Of the 2,047 respondents who were vaccinated, 1,626 (79.4%) thought they would accept antibody testing. Those who displayed more anxiety about acquiring COVID-19 disease were more likely to accept COVID-19 antibody testing. If the antibody test results showed protective antibodies, 1,190 (58.1%) were more likely to arrange travel plans in China, while 526 (25.7%) thought they would feel safer traveling abroad.

Conclusion

COVID-19 vaccination strategies help reduce public anxiety. However, public anxiety may be elevated as the local transmission of COVID-19 occurs in mainland China, which is usually caused now by imported cases. Those who display more anxiety choose to have antibody testing. Improving the accessibility of COVID-19 antibody tests can help ease public anxiety and enhance the confidence of some people to participate in social activities.

A rapid antibody screening haemagglutination test for predicting immunity to SARS-CoV-2 variants of concern

Background

Evaluation of susceptibility to emerging SARS-CoV-2 variants of concern (VOC) requires rapid screening tests for neutralising antibodies which provide protection.

Methods

Firstly, we developed a receptor-binding domain-specific haemagglutination test (HAT) to Wuhan and VOC (alpha, beta, gamma and delta) and compared to pseudotype, microneutralisation and virus neutralisation assays in 835 convalescent sera. Secondly, we investigated the antibody response using the HAT after two doses of mRNA (BNT162b2) vaccination. Sera were collected at baseline, three weeks after the first and second vaccinations from older (80-99 years, n = 89) and younger adults (23-77 years, n = 310) and compared to convalescent sera from naturally infected individuals (1-89 years, n = 307).

Results

Here we show that HAT antibodies highly correlated with neutralising antibodies (R = 0.72-0.88) in convalescent sera. Home-dwelling older individuals have significantly lower antibodies to the Wuhan strain after one and two doses of BNT162b2 vaccine than younger adult vaccinees and naturally infected individuals. Moverover, a second vaccine dose boosts and broadens the antibody repertoire to VOC in naïve, not previously infected older and younger adults. Most (72-76%) older adults respond after two vaccinations to alpha and delta, but only 58-62% to beta and gamma, compared to 96-97% of younger vaccinees and 68-76% of infected individuals. Previously infected older individuals have, similarly to younger adults, high antibody titres after one vaccination.

Conclusions

Overall, HAT provides a surrogate marker for neutralising antibodies, which can be used as a simple inexpensive, rapid test. HAT can be rapidly adaptable to emerging VOC for large-scale evaluation of potentially decreasing vaccine effectiveness.

Durable T-cellular and humoral responses in SARS-CoV-2 hospitalized and community patients

Background

Neutralizing antibodies are important for protection against the pandemic SARS-CoV-2 virus, and long-term memory responses determine the risk of re-infection or boosting after vaccination. T-cellular responses are considered important for partial protection against novel variants of concern.

Methods

A prospective cohort of hospitalized (n = 14) and community (n = 38) patients with rt-PCR confirmed SARS-CoV-2 infection were recruited. Blood samples and clinical data were collected when diagnosed and at 6 months. Serum samples were analyzed for SARS-CoV-2-spike specific antibodies using ELISA (IgG, IgA, IgM), pseudotype neutralization and microneutralization assays. Peripheral blood mononuclear cells were investigated for virus-specific T-cell responses in the interferon-γ and interleukin-2 fluorescent-linked immunosorbent spot (FluroSpot) assay.

Results

We found durable SARS-CoV-2 spike- and internal protein specific T-cellular responses in patients with persistent antibodies at 6 months. Significantly higher IL-2 and IFN-γ secreting T-cell responses as well as SARS-CoV-2 specific IgG and neutralizing antibodies were detected in hospitalized compared to community patients. The immune response was impacted by age, gender, comorbidity and severity of illness, reflecting clinical observations.

Conclusions

SARS-CoV-2 specific T-cellular and antibody responses persisted for 6 months post confirmed infection. In previously infected patients, re-exposure or vaccination will boost long-term immunity, possibly providing protection against re-infection with variant viruses.

Impact of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) vaccination on the incidence of coronavirus disease 2019 (COVID-19) among healthcare workers at an academic medical center in Vermont

Infection prevention strategies and vaccination reduce risk of severe acute respiratory coronavirus virus 2 (SARS-CoV-2) transmission to healthcare workers (HCWs). We describe coronavirus disease 2019 (COVID-19) incidence and vaccination rates in a cohort of HCWs at the University of Vermont Medical Center. Before vaccines, the HCW COVID-19 incidence paralleled that of the State of Vermont; after vaccination, incidence fell and remained low.

Prevalence of SARS-CoV-2 amongst ophthalmologists throughout the first and second waves of the pandemic

The study aims to investigate the prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among ophthalmology unit staff throughout the first and second waves of the outbreak, in order to verify the effectiveness of the measures adopted in containing the contagion.A retrospective observational study was conducted involving staff members, who received a naso/oropharyngeal swab when complaining of SARS-CoV-2 symptoms and once a month as a screening measure. They were tested for SARS-CoV-2 antibodies as a screening measure during the first and the second wave. Clinical activities performed during the outbreak were compared with those performed during the same period in 2019 and correlated with the number of coronavirus disease-2019 eye care workers.Analysis included 25 workers. Clinical infection was 0% and 12% whereas the prevalence of SARS-CoV-2 antibodies ranged from 4% to 8% in the first and second wave, respectively. The increase in the prevalence of SARS-CoV-2 infection between the first and the second wave was not significant (1/25 vs 3/25, P = .6092). Clinical activities significantly decreased during the first wave compared with the same period in 2019 (3256 vs 10,075, P < .0001, -68% to 2019), but increased during the second wave (8208 vs 3256, P < .0001, +152% to the first wave).Despite the increase in routine activities during the second wave, we did not observe a significant increase in SARS-CoV-2 prevalence. Strict protection measures seemed to contain the rate of contagion among the ophthalmology unit members even in a high-volume clinical setting in one of the most affected area by the coronavirus disease-2019 outbreak.

COVID-19 infection, progression, and vaccination: Focus on obesity and related metabolic disturbances

Coronaviruses are constantly circulating in humans, causing common colds and mild respiratory infections. In contrast, infection with the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), responsible for coronavirus disease-2019 (COVID-19), can cause additional severe complications, particularly in patients with obesity and associated metabolic disturbances. Obesity is a principal causative factor in the development of the metabolic syndrome; a series of physiological, biochemical, clinical, and metabolic factors that increase the risk of obesity-associated diseases. "Metabolically unhealthy" obesity is, in addition to metabolic disturbances, also associated with immunological disturbances. As such, patients with obesity are more prone to develop serious complications from infections, including those from SARS-CoV-2. In this review, we first describe how obesity and related metabolic disturbances increase the risk of SARS-CoV-2 infection. Then, mechanisms contributing to COVID-19 complications and poor prognosis in these patients are discussed. Finally, we discuss how obesity potentially reduces long-term COVID-19 vaccination efficacy. Despite encouraging COVID-19 vaccination results in patients with obesity and related metabolic disturbances in the short-term, it is becoming increasingly evident that long-term COVID-19 vaccination efficacy should be closely monitored in this vulnerable group.

Determinants and dynamics of SARS-CoV-2 infection in a diverse population: 6-month evaluation of a prospective cohort study

Background

We studied risk factors, antibodies, and symptoms of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in a diverse, ambulatory population.

Methods

A prospective cohort (n = 831) previously undiagnosed with SARS-CoV-2 infection underwent serial testing (SARS-CoV-2 polymerase chain reaction, immunoglobulin G [IgG]) for 6 months.

Results

Ninety-three participants (11.2%) tested SARS-CoV-2-positive: 14 (15.1%) asymptomatic, 24 (25.8%) severely symptomatic. Healthcare workers (n = 548) were more likely to become infected (14.2% vs 5.3%; adjusted odds ratio, 2.1; 95% confidence interval, 1.4–3.3) and severely symptomatic (29.5% vs 6.7%). IgG antibodies were detected after 79% of asymptomatic infections, 89% with mild-moderate symptoms, and 96% with severe symptoms. IgG trajectories after asymptomatic infections (slow increases) differed from symptomatic infections (early peaks within 2 months). Most participants (92%) had persistent IgG responses (median 171 days). In multivariable models, IgG titers were positively associated with symptom severity, certain comorbidities, and hospital work. Dyspnea and neurologic changes (including altered smell/taste) lasted ≥ 120 days in ≥ 10% of affected participants. Prolonged symptoms (frequently more severe) corresponded to higher antibody levels.

Conclusions

In a prospective, ethnically diverse cohort, symptom severity correlated with the magnitude and trajectory of IgG production. Symptoms frequently persisted for many months after infection.

Clinical Trials Registration. NCT04336215.

The front-line during the coronavirus disease 2019 pandemic: healthcare personnel

PURPOSE OF REVIEW

An estimated four to 11% of reported coronavirus disease 2019 (COVID-19) cases occurs in healthcare personnel (HCP). HCP are at high risk of acquiring and transmitting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) given their close contact with individuals with recognized and unrecognized COVID-19. We summarize the literature to date describing the epidemiology, identifying risk factors associated with COVID-19, and analyzing clinical characteristics and outcomes of SARS-CoV-2 infection in HCP.

RECENT FINDINGS

The prevalence of SARS-CoV-2 antibodies among HCP ranges from 0.7 to 45%. Although there is heterogeneity in the seroprevalence rate reported in the literature, HCP may be at increased risk of SARS-CoV-2 infection from exposure to patients with COVID-19. The literature supports that this can be minimized with adequate personal protective equipment (PPE) supply, proper hand hygiene, appropriate PPE use, and other infection prevention measures. In addition, infections in HCP are commonly acquired in the community as well as in nonclinical care settings including break rooms or work rooms.

SUMMARY

While much focus has been on minimizing patient-to-HCP transmission of SARS-CoV-2, additional efforts are needed to prevent exposures in nonclinical care settings and in the community.

SARS-CoV-2 antibody kinetics eight months from COVID-19 onset: Persistence of spike antibodies but loss of neutralizing antibodies in 24% of convalescent plasma donors

Elucidating the characteristics of human immune response against SARS-CoV-2 is of high priority and relevant for determining vaccine strategies. We report the results of a follow-up evaluation of anti-SARS-CoV-2 antibodies in 148 convalescent plasma donors who participated in a phase 2 study at a median of 8.3 months (range 6.8-10.5 months) post first symptom onset. Monitoring responses over time, we found contraction of antibody responses for all four antigens tested, with Spike antibodies showing higher persistence than Nucleocapsid antibodies. A piecewise linear random-effects multivariate regression analysis showed a bi-phasic antibody decay with a more pronounced decrease during the first 6 months post symptoms onset by analysis of two intervals. Interestingly, antibodies to Spike showed better longevity whereas their neutralization ability contracted faster. As a result, neutralizing antibodies were detected in only 76% of patients at the last time point. In a multivariate analysis, older age and hospitalization were independently associated with higher Spike, Spike-RBD, Nucleocapsid, N-RBD antibodies and neutralizing antibody levels. Results on persistence and neutralizing ability of anti-SARS-CoV-2 antibodies, especially against Spike and Spike-RBD, should be considered in the design of future vaccination strategies.

Long COVID in a prospective cohort of home-isolated patients

Long-term complications after coronavirus disease 2019 (COVID-19) are common in hospitalized patients, but the spectrum of symptoms in milder cases needs further investigation. We conducted a long-term follow-up in a prospective cohort study of 312 patients—247 home-isolated and 65 hospitalized—comprising 82% of total cases in Bergen during the first pandemic wave in Norway. At 6 months, 61% (189/312) of all patients had persistent symptoms, which were independently associated with severity of initial illness, increased convalescent antibody titers and pre-existing chronic lung disease. We found that 52% (32/61) of home-isolated young adults, aged 16–30 years, had symptoms at 6 months, including loss of taste and/or smell (28%, 17/61), fatigue (21%, 13/61), dyspnea (13%, 8/61), impaired concentration (13%, 8/61) and memory problems (11%, 7/61). Our findings that young, home-isolated adults with mild COVID-19 are at risk of long-lasting dyspnea and cognitive symptoms highlight the importance of infection control measures, such as vaccination.

Analysis of a prospectively enrolled cohort of patients with SARS-CoV-2 infections in Bergen, Norway, reveals a high proportion of patients who experienced long COVID symptoms at 6 months, despite being relatively young and having only mild to moderate acute COVID-19 symptoms.

Novel coronavirus seropositivity and related factors among healthcare workers at a university hospital during the prevaccination period: a cross-sectional study

BACKGROUND

This study aimed to investigate the specific risk factors for the transmission of novel coronavirus (SARS-CoV-2) among healthcare workers in different campuses of a university hospital and to reveal the risk factors for antibody positivity.

METHODS

In this retrospective cross-sectional study, 2988 (82%) of 3620 healthcare workers in a university hospital participated. The coronavirus disease 2019 (COVID-19) antibody was investigated using serum from healthcare workers who underwent COVID-19 antibody testing. The antibody test results of the participants were evaluated based on their work campus, their profession and their workplace. The statistical significance level was p < 0.05 in all analyses.

RESULTS

Of the participants in this study, 108 (3.6%) were antibody positive, and 2880 (96.4%) were negative. Antibody positivity rates were greater in nurses compared with other healthcare workers (p < 0.001). Regarding workplace, antibody positivity was greater in those working in intensive care compared to those working in other locations (p < 0.001).

CONCLUSIONS

Healthcare workers are at the highest risk of being infected with COVID-19. Those who have a higher risk of infection among healthcare workers and those working in high-risk areas should be vaccinated early and use personal protective equipment during the pandemic.

TRIAL REGISTRATION

Retrospective permission was obtained from both the local ethics committee and the Turkish Ministry of Health for this study (IRB No:71522473/050.01.04/370, Date: 05.20.2020).

Prevalence and Course of IgA and IgG Antibodies against SARS-CoV-2 in Healthcare Workers during the First Wave of the COVID-19 Outbreak in Germany: Interim Results from an Ongoing Observational Cohort Study

(1) Background: Healthcare workers (HCWs) are prone to intensified exposure to severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in the ongoing pandemic. We prospectively analyzed the prevalence of antibodies against SARS-CoV-2 in HCWs at baseline and follow up with regard to clinical signs and symptoms in two university hospitals in Brandenburg, Germany. (2) Methods: Screening for anti-SARS-CoV-2 IgA and IgG antibodies was offered to HCWs at baseline and follow up two months thereafter in two hospitals of Brandenburg Medical School during the first wave of the COVID-19 pandemic in Germany in an ongoing observational cohort study. Medical history and signs and symptoms were recorded by questionnaires and analyzed. (3) Results: Baseline seroprevalence of anti-SARS-CoV-2 IgA was 11.7% and increased to 15% at follow up, whereas IgG seropositivity was 2.1% at baseline and 2.2% at follow up. The rate of asymptomatic seropositive cases was 39.5%. Symptoms were not associated with general seropositivity for anti-SARS-CoV-2; however, class switch from IgA to IgG was associated with increased symptom burden. (4) Conclusions: The seroprevalence of antibodies against SARS-CoV-2 was low in HCWs but higher compared to population data and increased over time. Screening for antibodies detected a significant proportion of seropositive participants cases without symptoms.

SARS-CoV-2 Antibody Screening in Healthcare Workers in Non-Infectious Hospitals in Two Different Regions of Southern Poland (Upper Silesia and Opole Voivodeships): A Prospective Cohort Study

(1) Background: Detection of asymptomatic or subclinical human coronavirus SARS-CoV-2 infection in healthcare workers (HCWs) is crucial for understanding the overall prevalence of the new coronavirus and its infection potential in public (non-infectious) healthcare units with emergency wards. (2) Methods: We evaluated the host serologic responses, measured with semi-quantitative ELISA tests (IgA, IgG, IgM abs) in sera of 90 individuals in Hospital no. 4 in Bytom, 84 HCWs in the University Hospital in Opole and 25 in a Miasteczko Śląskie local surgery. All volunteers had negative RT-PCR test results or had not had the RT-PCR test performed within 30 days before sampling. The ELISA test was made at two different time points (July/August 2020) with a 2-weeks gap between blood collections to avoid the “serological window” period. (3) Results: The IgG seropositivity of asymptomatic HCWs varied between 1.2% to 10% (Opole vs. Bytom, p < 0.05; all without any symptoms). IgA seropositivity in HCWs was 8.8% in Opole and 7.14% in Bytom. IgM positive levels in HCWs in Opole and Bytom was 1.11% vs. 2.38%, respectively. Individuals with IgA and IgM seropositivity results were observed only in Opole (1.19%). More studies are needed to determine whether these results are generalizable to other populations and geographic as well as socio-demographic locations. (4) Conclusions: 100% of IgG(+) volunteers were free from any symptoms of infection in the 30 days before first or second blood collection and they had no awareness of SARS-CoV-2 infection. Asymptomatic HCWs could spread SARS-CoV-2 infection to other employees and patients. Only regular HCWs RT-PCR testing can reduce the risk of SARS-CoV-2 spreading in a hospital environment. The benefit of combining the detection of specific IgA with that of combined specific IgM/IgG is still uncertain.

SARS-CoV-2 RT-PCR positivity and antibody prevalence among asymptomatic hospital-based health care workers

Background

The level of asymptomatic infection with SARS-CoV-2 could be substantial and among health care workers (HCWs) a source of continuing transmission of the virus to patients and co-workers.

Objectives

Measure the period prevalence of SARS-CoV-2 PCR positivity and seroprevalence of SARS-CoV-2 IgG antibodies among a random sample of asymptomatic health system hospital-based health care workers (HCWs) 6½ -15½ weeks after 4/5/2020, the peak of the first surge of COVID-19 admissions.

Results

Of 524 eligible and consented participants from four metropolitan hospitals, nasopharyngeal swabs were obtained from 439 (83.8 %) and blood from 374 (71.4 %). Using PCR nucleic acid-based amplification (NAAT) methods, the period prevalence of SARS-CoV-2 infection was 0.23 % (95 % confidence interval (CI) 0.01 %–1.28 %; 1/439) from 5/21/20−7/16/20. The seroprevalence of SARS-CoV-2 IgG antibodies from June 17-July 24, 2020 was 2.41 % (95 % CI 1.27 %–4.51 %; 9/374). Those who were reactive were younger (median age 36 versus 44 years; p = 0.050), and those with self-reported Hispanic/Latino ethnicity had a higher seroprevalence (2/12 = 16.7 % versus 7/352 = 2.0 %; p = 0.051). There were no significant differences by sex, race, residence, hospital, unit or job type. The one employee who was found to be PCR test positive in this study was also reactive for IgG antibodies, tested 27 days later.

Conclusions

The period prevalence of PCR positivity to SARS-CoV-2 and IgG seroprevalence was unexpectedly low in asymptomatic HCWs after a peak in COVID-19 admissions and the establishment of state and institutional infection control policies, suggesting that routine screening tests while community prevalence is relatively low would produce a minimal yield.

Comparison of SARS-CoV-2 infections in healthcare workers with high and low exposures to Covid-19 patients in a Norwegian University Hospital

INTRODUCTION

A year into the pandemic, the knowledge of SARS-CoV-2 infection risks among healthcare workers remains limited. In this cross-sectional study, we examined whether healthcare workers with high exposure to Covid-19 patients had a higher risk of SARS-CoV-2 infection than other healthcare workers in a Norwegian University Hospital. We also investigated the prevalence of asymptomatic healthcare workers in a ward with a SARS-CoV-2 outbreak.

METHODS

Healthcare workers from five wards at Akershus University Hospital were included between May 11 and June 11, 2020. Blood samples were analyzed for SARS-CoV-2 antibodies and seroprevalences compared between participants with high and low exposure to Covid-19 patients. Demographic data and SARS-CoV-2 infection risk factors were recorded in a questionnaire. Naso-/oropharyngeal swabs from participants from the outbreak ward were analyzed by reverse transcriptase-polymerase chain reaction.

RESULTS

360/436 (82.6%) healthcare workers participated. 9/262 (3.4%) participants from wards with high exposure to Covid-19 patients were SARS-CoV-2 seropositive versus 3/98 (3.1%) from wards with low exposure (OR 1.13; 95%CI 0.3-4.26, p = .861). SARS-CoV-2 antibodies were found in 11/263 (4.2%) participants who had worked one or more shifts caring for Covid-19 patients versus in 1/85 (1.2%) without any known occupational Covid-19 exposure (OR 3.67; 95%CI 0.46-29.06, p = .187). SARS-CoV-2 was detected in naso-/oropharyngeal swabs from 2/78 (2.6%) participants.

CONCLUSION

We found no significantly increased risk of SARS-CoV-2 infection in healthcare workers with high exposure to COVID-19 patients. Five healthcare workers had either serologic or molecular evidence of past or present unrecognized SARS-CoV-2 infection.