Unvaccinated Healthcare Workers Research Articles

Long-term course of neutralising antibodies against SARS-CoV-2 in vaccinated and unvaccinated staff and residents in a Swiss nursing home: a cohort study 2021-2022.

Given their high-risk resident population, nursing homes were critical institutions in the COVID-19 pandemic, calling for continued monitoring and vaccine administration to healthcare workers and residents. Here, we studied long-term severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) immunity in vaccinated and unvaccinated healthcare workers and residents of a nursing home in Switzerland between February 2021 and June 2022. Our study comprised 45 participants, of which 39 were healthcare workers and six were residents. All participants were offered a maximum of three mRNA vaccine doses (Pfizer/BioNTech, BNT162b2) in December 2020, January 2021, and November/December 2021. Thirty-five participants received three vaccinations, seven either one or two, and three remained unvaccinated. We collected four blood samples: one in March 2021 and three during follow-ups in November 2021, February 2022, and June 2022. We performed a multifactorial serological SARS-CoV-2 assay (ABCORA) for immunoglobulin G, A, and M responses to spike (receptor-binding domain, S1, and S2) and nucleocapsid (N) proteins. Furthermore, we assessed predicted neutralisation activity based on signal over cutoff in ABCORA. We collected epidemiological data from participants via a standardised questionnaire. Thirty-two (71%) of the 45 participants showed hybrid immunity from combined vaccination and previous infection; 10 (22%) had only vaccine-induced immunity; and three (7%) had only post-infection immunity. Participants with hybrid immunity showed the highest predicted neutralisation activity at the end of the study period (median Sum S1 = 273), and unvaccinated participants showed the lowest (median Sum S1 = 41). Amongst participants who reported a SARS-CoV-2 infection, median Sum S1 levels increased with the number of vaccinations (p = 0.077). The healthcare worker group showed a significant time-dependent decrease in median Sum S1 after base immunisation (93% decrease, p = 0.0005) and the booster dose (26% decrease, p = 0.010). Predicted neutralisation activity was lower amongst residents (adjusted ratio of means [AM] = 0.7, 95% confidence interval [CI] = 0.3-1.0) and amongst smokers (AM = 0.5, 95% CI 0.3-0.8). Activity increased with the number of vaccinations (booster: AM = 3.6, 95% CI 1.5-8.8; no booster: AM = 2.3, 95% CI 0.9-2.5). Positive SARS-CoV-2 infection status tended to confer higher predicted neutralisation levels (AM = 1.5, 95% CI 0.9-2.5). Our study of the long-term serological course of SARS-CoV-2 in a nursing home showed that the first SARS-CoV-2 booster vaccine was essential for maintaining antiviral antibody levels. Hybrid immunity sustained SARS-CoV-2 immunity at the highest level. In critical settings such as nursing homes, monitoring the SARS-CoV-2 immune status may guide booster vaccinations.

Seroprevalence of SARS-CoV-2 antibodies among healthcare workers in Dutch hospitals after the 2020 first wave: a multicentre cross-sectional study with prospective follow-up

BackgroundWe aimed to estimate the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence and describe its determinants and associated symptoms among unvaccinated healthcare workers (HCWs) after the first wave of the pandemic.MethodsHCWs from 13 Dutch hospitals were screened for antibodies against the spike protein of SARS-CoV-2 in June-July 2020 and after three months. Participants completed a retrospective questionnaire on determinants for occupational and community exposure to SARS-CoV-2 and symptoms suggestive of COVID-19 experienced since January 2020. The seroprevalence was calculated per baseline characteristic and symptom at baseline and after follow-up. Adjusted odds ratios (aOR) for seropositivity were determined using logistic regression.ResultsAmong 2328 HCWs, 323 (13.9%) were seropositive at enrolment, 49 of whom (15%) reported no previous symptoms suggestive of COVID-19. During follow-up, only 1% of the tested participants seroconverted. Seroprevalence was higher in younger HCWs compared to the mid-age category (aOR 1.53, 95% CI 1.07–2.18). Nurses (aOR 2.21, 95% CI 1.34–3.64) and administrative staff (aOR 1.87, 95% CI 1.02–3.43) had a higher seroprevalence than physicians. The highest seroprevalence was observed in HCWs in the emergency department (ED) (aOR 1.79, 95% CI 1.10–2.91), the lowest in HCWs in the intensive, high, or medium care units (aOR 0.47, 95% CI 0.31–0.71). Chronic respiratory disease, smoking, and having a dog were independently associated with a lower seroprevalence, while HCWs with diabetes mellitus had a higher seroprevalence. In a multivariable model containing all self-reported symptoms since January 2020, altered smell and taste, fever, general malaise/fatigue, and muscle aches were positively associated with developing antibodies, while sore throat and chills were negatively associated.ConclusionsThe SARS-CoV-2 seroprevalence in unvaccinated HCWs of 13 Dutch hospitals was 14% in June-July 2020 and remained stable after three months. A higher seroprevalence was observed in the ED and among nurses, administrative and young staff, and those with diabetes mellitus, while a lower seroprevalence was found in HCWs in intensive, high, or medium care, and those with self-reported lung disease, smokers, and dog owners. A history of altered smell or taste, fever, muscle aches and fatigue were independently associated with the presence of SARS-CoV-2 antibodies in unvaccinated HCWs.

Prevalence of Post COVID-19 Condition among Healthcare Workers: Self-Reported Online Survey in Four African Countries, December 2021–January 2022

The impact of Post COVID-19 Condition (PCC) is ongoing despite the declaration that the 2019 COVID-19 pandemic has ended. In this study, we explore the prevalence of PCC among healthcare workers (HCWs) in four African Countries and its influence on their professional performance. This study was conducted as an online cross-sectional survey of healthcare workers from four African countries (Cameroon, Egypt, Nigeria, and Somalia) between the 20th of December 2021 to 12th of January 2022. We determined the prevalence of PCC based on the WHO case definition and assessed variables associated with a higher prevalence of PCC in these countries using univariable and multivariable logistic regression analyses. A total of 706 HCWs from four African countries were included in this survey. Most of the HCWs were aged between 18–34 years (75.8%, n = 535). Our findings showed that 19.5% (n = 138) of the HCWs had tested positive for SARS-CoV-2. However, 8.4% (n = 59) were symptomatic for COVID-19 but tested negative or were never tested. Two-thirds of the HCWs (66.4%, n = 469) have received a COVID-19 vaccine and 80.6% (n = 378) of those vaccinated had been fully vaccinated. The self-reported awareness rate of PCC among the HCWs was 16.1% (n = 114/706) whereas the awareness rate of PCC among COVID-19-positive HCWs was 55.3% (n = 109/197). The prevalence of PCC among HCWs was 58.8% (n = 116). These changes include the self-reported symptoms of PCC which included headache (58.4%, n = 115), fatigue (58.8%, n = 116), and muscle pain (39.6%, n = 78). Similarly, 30% (n = 59) and 20.8% (n = 41) of the HCWs reported the loss of smell and loss of taste long after their COVID-19 infection, respectively. Some HCWs (42%, n = 83) believed that their work performance has been affected by their ongoing symptoms of PCC. There was no significant difference in the prevalence of PCC among the vaccinated and unvaccinated HCWs (p > 0.05). Of the socio-demographic variables, age (older HCWs between 45–54 years; OR:1.7; 95% CI: 1.06, 10.59; p = 0.001) and location (Egypt; OR:14.57; 95% CI: 2.62, 26.76; p = 0.001) were more likely to have experienced PCC than other age groups and countries respectively. The study revealed a low prevalence of PCC among the surveyed HCWs. In addition, it observed the need for adequate medical and psychological support to HCWs with PCC and improved mass advocacy campaigns on PCC.

Differential abundance of lipids and metabolites related to SARS-CoV-2 infection and susceptibility

The mechanisms driving SARS-CoV-2 susceptibility remain poorly understood, especially the factors determining why unvaccinated individuals remain uninfected despite high-risk exposures. To understand lipid and metabolite profiles related with COVID-19 susceptibility and disease progression. We collected samples from an exceptional group of unvaccinated healthcare workers heavily exposed to SARS-CoV-2 but not infected (‘non-susceptible’) and subjects who became infected during the follow-up (‘susceptible’), including non-hospitalized and hospitalized patients with different disease severity providing samples at early disease stages. Then, we analyzed their plasma metabolomic profiles using mass spectrometry coupled with liquid and gas chromatography. We show specific lipids profiles and metabolites that could explain SARS-CoV-2 susceptibility and COVID-19 severity. More importantly, non-susceptible individuals show a unique lipidomic pattern characterized by the upregulation of most lipids, especially ceramides and sphingomyelin, which could be interpreted as markers of low susceptibility to SARS-CoV-2 infection. This study strengthens the findings of other researchers about the importance of studying lipid profiles as relevant markers of SARS-CoV-2 pathogenesis.

Seroprevalence of Apparently Healthy and Unvaccinated Healthcare Workers at the Ward of COVID Patients in a Referral Hospital, Dhaka, Bangladesh

Introduction: In Bangladesh, when a SARS-CoV-2 infected person comes to close contact with another person, especially unvaccinated healthcare workers (HCWs) during staying at the hospital, the disease spreads among the other patients also. This study was carried out in the initial stage of the Corona virus disease 2019 (COVID-19) pandemic before the vaccination program had started. It was observed that among the HCWs some were infected by the virus while they take care of the infected patients and some suffered from subclinical infection without significant symptoms whereas some were not infected at all. Objective: To observe the seroprevalence of SARS- CoV-2 antibodies in a specific group of people (HCWs) who were healthy and unvaccinated but exposed to the patients at the COVID ward in a referral hospital. Methods: This study was carried out in Immunology and Virology Department, Armed Forces Institute of Pathology (AFIP), Dhaka Bangladesh from the date of 21st April, 2020 to 31st May, 2020. As this study was carried out in very early stage of the COVID-19 pandemic, samples were collected within a short period that is for forty days only. In this study, 294 samples were collected from apparently healthy and unvaccinated HCWs who work at the COVID wards in a referral hospital. To detect SARS-CoV-2 antibodies, Immunochromatographic (ICT) method was applied which is a well-accepted method worldwide. Results: This study revealed that among 294 samples from healthcare workers, 36% (106) cases developed antibodies but 64% (188) cases didn’t develop any type of antibody and 19.3(57) cases were PCR positive which might be possible due to their duties in COVID ward. Among 106 seroconvert cases, 16.98% (18)were positive for only IgM, 50.9% (54) were positive for only IgG and 34(32.07%)) were positive for both IgG and IgM. Among 57 infected cases, 21.05% (12) were positive for only IgM, 45.61% (26) were positive for only IgG and 33.33% (34) were for both IgG and IgM antibodies. The ratio between male and female in health-workers were 2.58:1 respectively. Conclusion: This study revealed that the serological test of SARS-CoV-2 is useful for the identification of symptomatic, asymptomatic or subclinical infection among the persons who are the close contacts of COVID-19 patients; moreover, it will help to understand the disease outbreak, the contagiousness of SARS- CoV-2 and the immunity to SARS-CoV-2 in both the vulnerable and general populations. JAFMC Bangladesh. Vol 18, No 2 (December) 2022: 31-34

An Update on Human Papillomavirus Vaccination in the United States

ABSTRACT Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States in adults, and although most cases are transient, 10%–20% of infections can persist and progress to various forms of cancer. The HPV vaccine prevents more than 90% of HPV infections and HPV-associated cancers. The vaccine is most effective at preventing all types of HPV-related dysplasia in patients with no prior exposure to HPV. Reasons for decreased compliance include parent-specific factors such as education, safety concerns, absence of professional recommendation, and apprehension about supporting sexual behavior, whereas professional-level barriers include lack of time to discuss vaccination, knowledge gaps, vaccine access, and financial concerns. This clinical expert series highlights the evidence supporting the HPV vaccine as a safe and effective way to prevent cervical cancer. Most HPV infections are acquired in individuals aged 14–24 years with increasing prevalence with each year. Shared decision-making should be used for patients aged 27–45 years, in whom the vaccine has been demonstrated to be safe and effective, but the population advantage of vaccination is expected to be limited. Unvaccinated health care workers exposed to the virus in their practices should be vaccinated between the ages of 27 and 45 years. A previous HPV infection should not be a reason to not receive the vaccine, and it is not necessary to screen individual patients before vaccination. The vaccine is efficacious against other HPV types regardless of which HPV strain an individual may be positive for at the time of vaccination. Regarding women with HPV-related dysplasia such as high-grade squamous intraepithelial lesions that undergo excisional procedures, up to 15% will experience persistent or recurrent disease, and these women are at higher risk of developing a new HPV-associated lesion. Therefore, vaccination may provide a significant reduction in future disease in this patient population. The World Health Organization Strategic Advisory Group of Experts on Immunization recently evaluated the current scheduling regimens for the HPV vaccine and concluded that a single dose may provide enough protection in individuals younger than age 21; however, the Centers for Disease Control and Prevention is yet to comment. An ongoing large randomized, controlled, double-blinded, noninferiority trial (ESCUDDO) is currently evaluating a single-dose versus 2-dose regimen that will help elucidate whether vaccine scheduling in the United States may change to a single-dose paradigm. The strongest predictor of vaccine uptake is health care professional recommendation, and patients with prior infection or excision should still be offered the vaccine. Finally, although vaccination national guidelines are in place for individuals aged 9–26 years, certain patient populations older than 26 years may benefit from the vaccine.

Uptake of COVID-19 vaccines among healthcare workers and the effect of nudging interventions: A mixed methods study

BackgroundDuring the coronavirus disease (COVID-19) pandemic, vaccination of healthcare workers (HCWs) has a critical role because of their high-risk exposure and being a role model. Therefore, we aimed to investigate vaccine hesitancy and the role of mandatory polymerase chain reaction (PCR) testing and education for vaccine uptake. MethodsWe conducted an explanatory sequential designed observational mixed-methods study, including quantitative and qualitative sections consecutively in two different pandemic hospitals between 15 September 2021 and 1 April 2022. The characteristics of vaccinated and unvaccinated HCWs were compared. The vaccine hesitancy scales were applied, and the effect of nudging, such as mandatory PCR and education, were evaluated. In-depth interviews were performed to investigate the COVID-19 vaccine hesitancy among HCWs according to Health Belief Model. ResultsIn total, 3940 HCWs were included. Vaccine hesitancy was more common among males than females, the ancillary workers than other health professions, and nonmedical departments than other departments. After the mandatory weekly PCR request nudge, 83.33 % (130/156) vaccine-hesitant HCWs were vaccinated, and 8.3 % (13/156) after the small group seminars and mandatory PCR every two days. The rate of COVID-19 vaccination was raised from 95.5 % to 99.67 % (3927/3940). At the end of in-depth interviews (n = 13), the vaccine hesitancy determinants were distrust, fear of uncertainty, immune confidence and spirituality, the media effect, social pressure, and obstinacy. ConclusionsThe nudging interventions such as mandatory PCR testing and small group seminars helped raise the rate of COVID-19 vaccination; the most effective one is mandatory PCR.

Machine Learning Classification of Time since BNT162b2 COVID-19 Vaccination Based on Array-Measured Antibody Activity.

Vaccines trigger an immunological response that includes B and T cells, with B cells producing antibodies. SARS-CoV-2 immunity weakens over time after vaccination. Discovering key changes in antigen-reactive antibodies over time after vaccination could help improve vaccine efficiency. In this study, we collected data on blood antibody levels in a cohort of healthcare workers vaccinated for COVID-19 and obtained 73 antigens in samples from four groups according to the duration after vaccination, including 104 unvaccinated healthcare workers, 534 healthcare workers within 60 days after vaccination, 594 healthcare workers between 60 and 180 days after vaccination, and 141 healthcare workers over 180 days after vaccination. Our work was a reanalysis of the data originally collected at Irvine University. This data was obtained in Orange County, California, USA, with the collection process commencing in December 2020. British variant (B.1.1.7), South African variant (B.1.351), and Brazilian/Japanese variant (P.1) were the most prevalent strains during the sampling period. An efficient machine learning based framework containing four feature selection methods (least absolute shrinkage and selection operator, light gradient boosting machine, Monte Carlo feature selection, and maximum relevance minimum redundancy) and four classification algorithms (decision tree, k-nearest neighbor, random forest, and support vector machine) was designed to select essential antibodies against specific antigens. Several efficient classifiers with a weighted F1 value around 0.75 were constructed. The antigen microarray used for identifying antibody levels in the coronavirus features ten distinct SARS-CoV-2 antigens, comprising various segments of both nucleocapsid protein (NP) and spike protein (S). This study revealed that S1 + S2, S1.mFcTag, S1.HisTag, S1, S2, Spike.RBD.His.Bac, Spike.RBD.rFc, and S1.RBD.mFc were most highly ranked among all features, where S1 and S2 are the subunits of Spike, and the suffixes represent the tagging information of different recombinant proteins. Meanwhile, the classification rules were obtained from the optimal decision tree to explain quantitatively the roles of antigens in the classification. This study identified antibodies associated with decreased clinical immunity based on populations with different time spans after vaccination. These antibodies have important implications for maintaining long-term immunity to SARS-CoV-2.

The importance of combining serological testing with RT-PCR assays for efficient detection of COVID-19 and higher diagnostic accuracy.

Misdiagnosing suspected COVID-19 individuals could largely contribute to the viruses transmission, therefore, making an accurate diagnosis of infected subjects vital in minimizing and containing the disease. Although RT-PCR is the standard method in detecting COVID-19, it is associated with some limitations, including possible false negative results. Therefore, serological testing has been suggested as a complement assay to RT-PCR to support the diagnosis of acute infections. In this study, 15 out of 639 unvaccinated healthcare workers (HCWs) were tested negative for COVID-19 by RT-PCR and were found seropositive for SARS-CoV-2 nucleocapsid protein-specific IgM and IgG antibodies. These participants underwent additional confirmatory RT-PCR and SARS-CoV-2 spike-specific ELISA tests. Of the 15 individuals, nine participants were found negative by second RT-PCR but seropositive for anti-spike IgM and IgG antibodies and neutralizing antibodies confirming their acute infection. At the time of collection, these nine individuals were in close contact with COVID-19-confirmed patients, with 77.7% reporting COVID-19-related symptoms. These results indicate that including serological tests in the current testing profile can provide better outcomes and help contain the spread of the virus by increasing diagnostic accuracy to prevent future outbreaks rapidly.

Systemic reactogenicity following homologues and heterologous prime-boost AZD1222 and BNT162b2 COVID-19 vaccination of 2862 healthcare workers compared with an unvaccinated population

During spring 2021, AZD1222 and BNT162b2 were used as prime and BNT162b2 as booster COVID-19 vaccines in Denmark. We obtained self-reported information on systemic reactogenicity day-by-day during two weeks for 2862 healthcare workers vaccinated with heterologous AZD1222+BNT162b2 or homologous BNT162b2+BNT162b2 regimens and compared prevalences of symptoms with unvaccinated healthcare workers. We found comparable systemic reactogenicity during the first week in the two vaccine regimens and no reactogenicity during the second week. Most of the symptoms returned to a level equal to the control population four days after booster vaccination.

Features of the Formation of Seroprevalence to SARS-CoV2 in the Population of the Republic of Tatarstan during the Spread of COVID-19

Relevance. It is relevant to study the features of the formation and duration of the humoral immune response to a new coronavirus infection in a high-risk group of infection - among medical workers. Aims. To study the dynamics of the levels of specific antibodies (IgM and IgG) to SARS-CoV2 in unvaccinated MRs of the temporary infectious diseases hospital to assess the trends of the individual humoral immune response to a new coronavirus infection. Materials and methods. We monitored IgM and IgG to SARS-CoV-2 in 68 unvaccinated healthcare workers monthly from July 2020 to July 2021 by two-stage direct solid-phase ELISA using the test systems «SARS-CoV-2-IgG-ELISA-BEST» and «SARS-CoV-2-IgM-ELISA-BEST», Russia. Among them, there were 26.5% men and 73.5% women, the average age was 43.5 ± 1.51 years, doctors 52.9%, paramedical personnel 36.8% and junior staff 10.3%. 69.1% had a history of clinical manifestations of COVID19, among them 42.7% had a mild infection, 20.6% had a moderate infection, and 5.9% had a severe infection, 30.9% were asymptomatic. Statistical processing were carried out using the methods of variation statistics using the Excel statistical package and the WinPepi software product (version 11.65). Results. A decrease in the geometric mean value of IgM titers to SARS-CoV-2 (average monthly decrease of 6.40%) and an increase in the geometric mean value of IgG titers (average monthly increase of 4.26%). An individual assessment of the dynamics of antibodies from the day with the first positive result showed a decrease in the geometric mean values of antibody titers and IgM and IgG to SARS-CoV-2 (monthly average decrease of -23.56% and -1.18%, respectively). An individual assessment of the immune response made it possible to distinguish three groups according to the dynamics of IgM: M0 -IgM in the blood were absent (50 ± 5.7446%); M1 -IgM persisted for 1–2 months, followed by a rapid decrease in titer (16.176 ± 3.7943%); M2 – IgM remained in the blood for three or more months (33.824 ± 5.1033%). By the nature of the dynamics of IgG MR were divided into four troupes. With a downward trend in IgG titer: G0 – IgG does not exceed 95% of the upper confidence limit of the individual trend in any of the samples taken (19.118 ± 4.7686%), G1 – does not exceed 95% of the upper confidence limit of the individual trend starting from 3 months after the start observations (4.412 ± 2.4903%), G2 – there is an excess of 95% of the upper confidence limit of the individual trend starting from 3 months after the start of observation (69.118 ± 5.6027%); G3 – with a trend of increasing IgG titer (7.353 ± 3.1651%). Сonclusions. The results of serological monitoring as a whole indicate the formation of herd immunity in this cohort. Monitoring the intensity of the individual immune response to SARS-CoV-2 throughout the year reflects the natural course of the infectious process and is the basis for vaccination against COVID-19. The results of serological monitoring can be used to predict the epidemiological situation, plan specific and non-specific COVID-19, personalization of vaccination.

Hepatitis B vaccination status and knowledge, attitude, and practice of hepatitis B among medical students at a medical college in central India

Background: Hepatitis B virus (HBV) infection imposes a major public health problem with an increased risk of occupational exposure among unvaccinated health care workers (HCWs). This study was conducted to determine the Hepatitis B vaccination status, along with the knowledge, attitude, and practice regarding Hepatitis B, among medical students at a medical college in a central India. Methods: A cross-sectional study was conducted from February 2022 to July 2022. A total of 477 students of health care professions were included into the study using a whole sampling technique. Data were collected using self-administered structured questionnaire and analyzed by using statistical package for the social sciences (SPSS) version 26. Results: Response rate was 91.61% (437). Majority of the students (>80%) had an adequate knowledge on risk factors for HBV, its mode of transmissions, and preventions. About 192 of 437 (43.9%) participants had positive attitude towards following infection control guidelines, and 310 (70.9%) respondents believe that all HCWs should take HBV vaccine. However, only 11.2% students had completed the three doses schedule of HBV vaccination. Whereas, a significant number of students, 142 (32.5%), had been exposed to blood/body fluid via needle stick injury at least once since they started their training in the health facility. Conclusions: Study found that trainees in health profession are at a very high risk of contracting HBV infection during their training due to the low HBV vaccine uptake rate and high rate of accidental exposure to blood. We recommend that all students in the health profession should be vaccinated prior to their entry into professional practices.

Uptake of Influenza Vaccine and Factors Associated with Influenza Vaccination among Healthcare Workers in Tertiary Care Hospitals in Bangladesh: A Multicenter Cross-Sectional Study.

Influenza, highly contagious in hospital settings, imposes a substantial disease burden globally, and influenza vaccination is critical for healthcare workers (HCWs) to prevent this illness. This study assessed influenza vaccine uptake, including its associated factors among HCWs of tertiary care hospitals in Bangladesh. Between September and December 2020, this multicenter study included 2046 HCWs from 11 hospitals. Face-to-face interviews were conducted using a semi-structured questionnaire to collect data from physicians, nurses, and cleaning and administrative staff for the survey. Only 13.8% (283/2046) of HCWs received the influenza vaccine, of which the majority (76.7%, 217/283) received it for free from the hospital. Nurses had the highest (20.0%, 187/934) influenza vaccine coverage, followed by physicians at 13.5% (71/526), whereas cleaning staff had the lowest at 6.0% (19/318). Among unvaccinated HCWs, the desire to get vaccinated was high (86.2%), with half of the respondents even being willing to pay for it. The HCWs who were aware of the influenza vaccine were over five times more likely to get the vaccine (OR 5.63; 95% CI: 1.04, 1.88) compared to those who were not. HCWs in Bangladesh were vaccinated against influenza at a very low rate. Free and mandatory influenza vaccination programs should be initiated to optimize vaccine coverage among HCWs.

Low influenza vaccine uptake by healthcare workers caring for the elderly in South African old age homes and primary healthcare facilities

BackgroundThe elderly bear the highest burden of South Africa’s estimated annual > 10 million influenza cases and > 11,000 influenza-related deaths. Unvaccinated healthcare workers (HCWs) are at high occupational risk of contracting influenza, and may transmit influenza to elderly patients in their care. Thus, the South African National Department of Health recommends that HCWs receive annual influenza vaccination. This study aimed to determine influenza vaccination coverage among HCWs; identify reasons for their vaccination status; and investigate if HCWs recommend vaccination to their elderly patients.MethodsA descriptive study was conducted in 18 community health centres and 44 private sector and non-governmental organisation managed old age homes across South Africa, using a self-administered structured questionnaire, which was distributed to 360 HCWs present on the day of data collection. Data were captured using Microsoft Excel® and imported to Epi Info™ 7 (Centers for Disease Control and Prevention, USA) for descriptive statistical analysis. Ethics approval (SMUREC/P/36/2018: PG) and permission to conduct the study at the facilities were obtained. All participants provided informed consent.ResultsThe response rate was 76.7% (276/360). Most participants were female (90.9% [251/276]), nursing professionals (81.2% [224/276]) with a mean age of 41.1 ± 11.7 years. Although 62.7% of participants indicated having ever received at least one dose of the influenza vaccine, influenza vaccine uptake for 2017 and 2018 was 24.36% (41/276) and 33.3% (92/276) respectively. The main reasons given for never being vaccinated against influenza were related to the unavailability of the vaccine (70.9%) and vaccine hesitancy (27.2%). Most participants (67.8% [187/276]) recommended vaccines to elderly patients in their care.ConclusionThe main reasons behind low influenza vaccine uptake by HCWs in South Africa who care for the elderly were related to unavailability of the vaccine and vaccine hesitancy. Strategies to educate HCWs on the importance of influenza vaccination, while concurrently increasing sustained and easy access to the vaccine by HCWs are needed to preserve public health.

SARS-CoV-2 antibody response after mRNA vaccination in healthcare workers with and without previous COVID-19, a follow-up study from a university hospital in Poland during 6 months 2021.

Healthcare workers (HCWs) from the beginning of the pandemic have been at risk of exposure to SARS-CoV-2, so they were vaccinated as first. The purpose of the study was to determine the level of antibodies against SARS-CoV-2 in HCWs before and after vaccination with mRNA preparations according to previous COVID- 19. The HCWs from the University Hospital in Krakow completed two surveys: the baseline survey before receiving the first dose of vaccine (in January 2021) and the follow-up survey in June 2021. In parallel, two blood samples were collected from each participant at baseline and at follow-up. Total anti-SARS-CoV-2 antibody levels were measured using the ECLIA technique. At baseline, 41.1% of HCWs had positive antibody test results, and at follow-up, the vaccinated HCWs had almost 100 times higher antibody levels than the unvaccinated HCWs. Participants under 30 years of age had significantly higher antibody levels in June than older HCWs. Among participants with positive antibody test results in January, HCWs who had experienced asymptomatic COVID-19 had more than five times higher antibody levels in June than HCWs self-reported severe COVID-19. In total, 86.9% of HCWs received Comirnaty or Spikevax. The incidence rate of COVID-19 in the unvaccinated vs. vaccinated group was 13 times higher, 20.5% and 1.9% respectively. These results confirm the effectiveness of vaccination in the prevention of COVID-19 in HCWs. It is worth getting vaccinated regardless of previous infection. Furthermore, vaccination among HCWs under 30 years of age induced more effective antibody production compared to older individuals.

Comparison of infection severity of vaccinated and unvaccinated health workers with Corona Virus: A cohort study.

Hospital staff members are most susceptible to the COVID-19 illness, which is currently prevented through vaccination. Hospital staff members also refuse vaccinations, albeit the underlying causes have not been identified. The study aimed to compare the severity of the symptoms of the disease on the body for health workers who took the coronavirus vaccine and those who did not take the vaccine. This cohort study aimed to estimate the of infection severity of vaccinated and unvaccinated health workers with Corona Virus in Mosul Hospital, Iraq. Data were obtained from the General Mosul Hospital, Nineveh, Iraq. The first of the three components of this questionnaire outlined the demographic characteristics. Second part: First group of unvaccinated Health care workers included those who had not received the COVID-19 immunization or had only gotten one dose of the vaccine; the second group included those who had received their first dose of Corona vaccine and the third group included those who had received two doses of Corona Vaccine. HCWs who got corona vaccine were included in the three-dose final group. The study's findings indicate that as compared to the corona vaccination, the vaccinated experienced less severe infection symptoms and fewer dosage stays. The high share of healthcare workers among the 20- to 30-year-olds who received vaccinations accounts for the gender gap between the vaccinated and unvaccinated groups. This study concluded that the results of the corona vaccine are not consistent among the various groups of HCWs. The acceptability of vaccinations is practically unanimous among nurses, but less so among doctors and other healthcare professionals.

Impact of COVID-19 Vaccination on Seroprevalence of SARS-CoV-2 among the Health Care Workers in a Tertiary Care Centre, South India.

Global vaccine development efforts have been accelerated in response to the devastating COVID-19 pandemic. The study aims to determine the seroprevalence of SARS-CoV-2 IgG antibodies among vaccine-naïve healthcare workers and to describe the impact of vaccination roll-out on COVID-19 antibody prevalence among the health care centers in tertiary care centers in South India. Serum samples collected from vaccinated and unvaccinated health care workers between January 2021 and April 2021were subjected to COVID-19 IgG ELISA, and adverse effects after the first and second dose of receiving the Covishield vaccine were recorded. The vaccinated group was followed for a COVID-19 breakthrough infection for a period of 6 months. Among the recruited HCW, 156 and 157 participants were from the vaccinated and unvaccinated group, respectively. The seroprevalence (COVID-19 IgG ELISA) among the vaccinated and unvaccinated Health Care Workers (HCW) was 91.7% and 38.2%, respectively, which is statistically significant. Systemic and local side-effects after Covishield vaccination occur at lower frequencies than reported in phase 3 trials. Since the COVID-19 vaccine rollout has commenced in our tertiary care hospital, seropositivity for COVID-19 IgG has risen dramatically and clearly shows trends in vaccine-induced antibodies among the health care workers.

Predictors and characteristics of post-acute COVID-19 syndrome in healthcare workers

Background Post-acute COVID-19 syndrome (PCS) is a multisystem disorder degrading the quality of life. The study determined characteristics and predictors of PCS in unvaccinated healthcare workers (HCWs) suffering from PCS based on a comparison with their fully recovered counterparts. Methods 305 HCWs were examined at least 12 weeks post COVID-19 symptom onset to obtain data about their acute phase of COVID-19 and current health status and tested for complete blood count, C-reactive protein (CRP), electrophoresis of plasma proteins and SARS-CoV-2-specific immunoglobulin (Ig) G and M. Results 181 (59.3%) HCWs reported persisting symptoms attributable to PCS during the examination and 124 (40.7%) HCWs stated no symptoms. In the entire sample, the mean CRP level slightly exceeded the normal range (6.63 mg/L, 95% confidence interval [CI] 5.96–7.3) while all other laboratory results were within the normal range. No statistically significant differences in laboratory results were revealed between both subgroups except for the mean Ig levels, which were higher in HCWs with PCS. The average number of symptoms of PCS was 1.9 (median 2). The most frequent symptoms of PCS were fatigue that interfered with daily life (47.5%), shortness of breath (38.1%), muscle or joint aches (16%), loss of smell (14.9%), headache (14.9%) and sleep disorders (11%). The only statistically significant predictors of PCS were female sex (odds ratio [OR] 1.48, 95% CI 1.059–2.067, p = .022) and increasing age (OR 1.04, 95% CI 1.01–1.07, p = .008). Conclusions PCS appears to be a prevalent condition determined by female sex and increasing age.

Protection against omicron (B.1.1.529) BA.2 reinfection conferred by primary omicron BA.1 or pre-omicron SARS-CoV-2 infection among health-care workers with and without mRNA vaccination: a test-negative case-control study

BackgroundThere is a paucity of data on vaccine-induced or infection-induced (hybrid or natural) immunity against omicron (B.1.1.529) subvariant BA.2, particularly in comparing the effects of previous SARS-CoV-2 infection with the same or different genetic lineage. We aimed to estimate the protection against omicron BA.2 associated with previous primary infection with omicron BA.1 or pre-omicron SARS-CoV-2, among health-care workers with and without mRNA vaccination.MethodsWe conducted a test-negative case-control study among health-care workers aged 18 years or older who were tested for SARS-CoV-2 in Quebec, Canada, between March 27 and June 4, 2022, when BA.2 was the predominant variant and was presumptively diagnosed with a positive test result. We identified cases (positive test during study period) and controls (negative test during study period) using the provincial laboratory database that records all nucleic acid amplification testing for SARS-CoV-2 in Quebec, and used the provincial immunisation registry to determine vaccination status. Logistic regression models compared the likelihood of BA.2 infection or reinfection (second positive test ≥30 days after primary infection) among health-care workers who had previous primary infection and none to three mRNA vaccine doses versus unvaccinated health-care workers with no primary infection.Findings258 007 SARS-CoV-2 tests were done during the study period. Among those with a valid result and that met the inclusion criteria, there were 37 732 presumed BA.2 cases (2521 [6·7%] reinfections following pre-omicron primary infection and 659 [1·7%] reinfections following BA.1 primary infection) and 73 507 controls (7360 [10·0%] had pre-omicron primary infection and 12 315 [16·8%] had BA.1 primary infection). Pre-omicron primary infection was associated with a 38% (95% CI 19–53) reduction in BA.2 infection risk, with higher BA.2 protection among those who had also received one (56%, 95% CI 47–63), two (69%, 64–73), or three (70%, 66–74) mRNA vaccine doses. Omicron BA.1 primary infection was associated with greater protection against BA.2 infection (risk reduction of 72%, 95% CI 65–78), and protection was increased further among those who had received two doses of mRNA vaccine (96%, 95–96), but was not improved with a third dose (96%, 95–97).InterpretationHealth-care workers who had received two doses of mRNA vaccine and had previous BA.1 infection were subsequently well protected for a prolonged period against BA.2 reinfection, with a third vaccine dose conferring no improvement to that hybrid protection. If this protection also pertains to future variants, there might be limited benefit from additional vaccine doses for people with hybrid immunity, depending on timing and variant.FundingMinistère de la Santé et des Services Sociaux du Québec.

Antibodies to NCP, RBD and S2 SARS-CoV-2 in Vaccinated and Unvaccinated Healthcare Workers.

In a few months, the SARS-CoV-2 virus caused a worldwide COVID-19 pandemic. In Poland, 6 million cases of the disease and 113,000 deaths from COVID-19 have been reported. Healthcare workers (HCWs) constitute one of the main COVID-19 risk groups. The Microblot-Array COVID-19 IgG assay was used to detect antibodies against three major SARS-CoV-2 antigens: nucleocapsid (NCP), RBD, and Spike 2 (S2). The aim of our study was to determine the seroprevalence and titer of anti-SARS-CoV-2 IgG antibodies—NCP, RBD, and S2—as markers of the humoral response in vaccinated and unvaccinated HCWs. The study included 203 persons who were divided into four groups: “COVID-19 Vaccinated”, “COVID-19 Unvaccinated”, “Non-COVID-19 Vaccinated”, and “Non-COVID-19 Unvaccinated”. The obtained results indicate that both seroprevalence and the antibody titer are the highest in the “COVID-19 Vaccinated” group. There is no so-called sterile vaccination, and after 6 months from the second dose of vaccine, most vaccinated people have a fairly high level of antibodies. We suggest that multiple vaccination and continuous testing are necessary. The Microblot-Array assay can distinguish between antibodies acquired after infection and/or vaccination.