Vaccination Of Healthcare Workers Research Articles

Vaccination Strategies against Seasonal Influenza in Long Term Care Setting: Lessons from a Mathematical Modelling Study

seasonal influenza in nursing homes is a major public health concern, since in EU 43,000 long term care (LTC) facilities host an estimated 2.9 million elderly residents. Despite specific vaccination campaigns, many outbreaks in such institutions are occasionally reported. We explored the dynamics of seasonal influenza starting from real data collected from a nursing home located in Italy and a mathematical model. Our aim was to identify the best vaccination strategy to minimize cases (and subsequent complications) among the guests. after producing the contact matrices with surveys of both the health care workers (HCW) and the guests, we developed a mathematical model of the disease. The model consists of a classical SEIR part describing the spreading of the influenza in the general population and a stochastic agent based model that formalizes the dynamics of the disease inside the institution. After a model fit of a baseline scenario, we explored the impact of varying the HCW and guests parameters (vaccine uptake and vaccine efficacy) on the guest attack rates (AR) of the nursing home. the aggregate AR of influenza like illness in the nursing home was 36.4% (ward1 = 56%, ward2 = 33.3%, ward3 = 31.7%, ward4 = 34.5%). The model fit to data returned a probability of infection of the causal contact of 0.3 and of the shift change contact of 0.2. We noticed no decreasing or increasing AR trend when varying the HCW vaccine uptake and efficacy parameters, whereas the increase in both guests vaccine efficacy and uptake parameter was accompanied by a slight decrease in AR of all the wards of the LTC facility. from our findings we can conclude that a nursing home is still an environment at high risk of influenza transmission but the shift change room and the handover situation carry no higher relative risk. Therefore, additional preventive measures in this circumstance may be unnecessary. In a closed environment such as a LTC facility, the vaccination of guests, rather than HCWs, may still represent the cornerstone of an effective preventive strategy. Finally, we think that the extensive inclusion of real life data into mathematical models is promising and may represent a starting point for further applications of this methodology.

Risk of Infection and Duration of Protection after the Booster Dose of the Anti-SARS-CoV-2 Vaccine BNT162b2 among Healthcare Workers in a Large Teaching Hospital in Italy: Results of an Observational Study.

The efficacy of the first schedule of COVID-19 mRNA vaccines has decreased after the surge of the Delta variant, posing the need to administer a booster dose to enhance the neutralising immune response. This study aims at evaluating the duration of protection given by the booster dose of Pfizer-BioNTech BNT162b2 mRNA vaccine in healthcare workers (HCWs) of a large teaching hospital in Rome and to analyse the factors associated with post-booster vaccination infections. Data about vaccinations of HCWs with the BNT162b2 vaccine and nasal swabs positive for SARS-CoV-2 were extracted from the digital archives of the hospital from 27 September 2021 to 31 May 2022. In total, 5770 HCWs were observed. The cumulative risk of becoming infected by SARS-CoV-2 increased with time (2.5% at 4 weeks, 17% at 12 weeks and 40% at 24 weeks) and was significantly higher for females, younger classes of patients and for those who had developed a hybrid immunity (natural infection plus one dose, namely the primary schedule, added to the booster dose) compared to those who had completed the three doses. This study describes the duration and the determinants of the protection against infections after the booster dose of COVID-19 vaccine, highlighting the need for continuous monitoring of vaccine-induced immunogenicity.

Mpox: What Practicing Gastroenterologists Need to Know

Mpox: What Practicing Gastroenterologists Need to Know

1949. Evaluation of cellular and humoral immune-responses at different times after SARS-COV-2 vaccination in health care workers cohort

Abstract Background We studied immunological response against SARS-CoV-2 after two doses of vaccine in health care workers (HCW) at our Infectious Disease Unit Methods We enrolled prospectively HCW without (group A) and with previous infection (group B). We collected peripheral blood at baseline (before the BNT162b2 vaccine), T1 (before the 2nd dose), T2 and T6 (after 1 and 6 months after of 2nd dose). The activation induced cell marker assay (AIM) was performed with CD4 and CD8 Spike peptide megapools (MPs). We evaluated the Stimulation Index (SI) as AIM+ stimulated cells/negative control (positive response SI >= 2). Quantitative antibodies (Abs) to Spike-1 protein (S) and to nucleocapside protein (N) were detected with an electrochemiluminescence immunoassay. We tested at T6 the responses to alpha, beta, gamma, delta and epsilon variants MPs.We used the linear mixed model with random intercept adjusted for age and sex to compare specific times to T0. To assess differences over time between groups the interaction with time was tested. Results In group A 13/22 (59%) were female vs 5/7 (71%) group B, the mean age 40 vs 38 years, respectively. For CD4+ Spike the overall rate of change over time was significant at T1 (p=0.038) and at T2 (p< 0.001) vs T0 with a decreasing at T6 (p not significant) [Figure 1] with a trend of higher response in group A. In group B the CD8+ Spike reactivity increased at T1(p=0.037) and at T6 (p=0.005) vs T0. The interaction between SI and time was statistically significant at T1 (p=0.033); T2 (p= 0.046) and T6 (p=0.035) (mean values in group B higher than A). For overall population, the anti-S Abs significantly increased at T1 vs T0, T2 vs T0 and at T6 vs T0 [Figure 2A]. The group B at T6 retained a higher anti S response but the rate of change significantly differs between the two group (overall interaction: p< 0.001) [Figure 2B]. At T6 in both groups we found a high CD4+ T cells response to epsilon variant, even if not detected as circulant virus. Quantitative (U/ml) values of anti-S Antibodies. Conclusion The humoral response was persistent and increased in previous infected subjects. The CD4+T cells response after vaccination retained a response in uninfected subject, with an increasing trend and with a response to non-circulating variants. The vaccine could help the CD8+ T cells reactivity specific for Spike peptides. Disclosures Chiara Dentone, CD, Angelini: Advisor/Consultant|Gilead: Advisor/Consultant|Menarini: Advisor/Consultant|Novartis: Advisor/Consultant Lucia Taramasso, LT, Gilead: Advisor/Consultant|Janssen: Advisor/Consultant|ViiV: Advisor/Consultant Alessandro Sette, AS, Arcturus Therapeutics: Grant/Research Support|Astrazeneca: Advisor/Consultant|Avalia: Advisor/Consultant|CellCarta: Grant/Research Support|Flow Pharma: Grant/Research Support|Fortress: Advisor/Consultant|Gritstone Bio: Advisor/Consultant|ImmunoScape: Advisor/Consultant|Moderna: Advisor/Consultant|Repertoire: Advisor/Consultant Antonio Di Biagio, AD, Abbvie: Advisor/Consultant|Gilead: Grant/Research Support|Janssen: Advisor/Consultant|MSD: Advisor/Consultant|ViiV: Advisor/Consultant Matteo Bassetti, PhD, Angelini: Advisor/Consultant|Astellas: Grant/Research Support|Bayer: Advisor/Consultant|Bayer: Honoraria|BioMe ́ rieux: Advisor/Consultant|BioMe ́ rieux: Honoraria|Cidara: Advisor/Consultant|Cidara: Honoraria|Cipla: Advisor/Consultant|Cipla: Honoraria|Gilead: Advisor/Consultant|Gilead: Honoraria|Menarini: Advisor/Consultant|Menarini: Honoraria|MSD: Advisor/Consultant|MSD: Honoraria|Nabriva: Advisor/Consultant|Pfizer: Advisor/Consultant|Pfizer: Board Member|Pfizer: Grant/Research Support|Pfizer: Honoraria|Shionogi: Advisor/Consultant|Shionogi: Honoraria|Tetraphase: Advisor/Consultant.

435. Investigation of the cause of low measles seroprevalence among young healthcare workers in South Korea

Abstract Background After a large measles outbreak in 2000∼2001, national measles vaccination program was implemented in Korea, and more than 95% of people born after 1985 have been vaccinated with 2-dose MMR. But sporadic outbreaks have continued to occur mainly in adults in their 20’s and 30’s in 2014 and 2019. Although low prevalence in young adults have been reported, there are limited data regarding the cause of low seropositivity (positive vaccine failure vs. secondary vaccine failure). We aimed to evaluate the cause of low seroprevalence of measles. Methods This study was performed in a 2743-bed tertiary-care hospital in South Korea. At 1-month after MMR vaccination in healthcare workers (HCWs) who were seronegative for measles, we performed measles antibody test(enzyme immunoassay), IgM/IgG index ratio, and avidity test. Results Of the 1,698 new HCWs in 2020 and, 1,686 in 2021, 54 HCWs with negative measles IgG at their entering at our hospital were enrolled in this study. Of these, 36(67%) were female, and the median age was 25 (IQR, 24-27) years. Of 43 HCWs who measured IgM/IgG index 1 month after MMR vaccination, 38 HCWs had IgM/IgG index of less than 1 and remaining 5 had negative IgG results (seroconversion rate of 88%). All 54 healthcare workers who performed avidity test showed high avidity index Measles vaccination record in KCDA showed that 45 had documented vaccination record during their childhood (of these, 11 received MMR vaccine again during their adult age) and remaining 9 had no documented vaccination record during their childhood. Of these 9 healthcare workers without record in their childhood, 3 had a history of vaccination at adult. Analyzing 48 healthcare workers with vaccination record, they received MMR vaccination median 18 years (IQR, 7-20) before. Therefore, at least 48 received at least 2 dose MMR vaccination, and 11 received at least 3 dose MMR vaccination. Conclusion Secondary vaccine failure may be the reason for vaccine failure in young adults in Korea. Therefore, HCWs with negative measles antibody who were born after 1985 may receive 1 dose booster vaccination rather than 2 dose vaccination. Disclosures All Authors: No reported disclosures.

1467. Breakthrough Omicron Infections in Booster Vaccinated Healthcare Workers

Abstract Background There are few data on immune correlation of protection from breakthrough Omicron (B.1.1.529) infection in individuals who received booster vaccines. We thus compared a neutralizing antibody titers against Omicron within the first month after the mRNA booster at the time before omicron wave between healthcare works (HCWs) who experienced Omicron breakthrough infections and HCWs without Omicron infections. Methods We enrolled HCWs without the history of SARS-CoV-2 infection who agreed with blood sampling 2 weeks after booster vaccination at Asan Medical Center, Seoul, South Korea, between November 2021 and December 2022 (Delta dominant era). We identified breakthrough infections by performing SARS-CoV-2 RT-PCR though nasopharyngeal swab specimen in HCWs who had COVID-19-related symptoms or had known exposure to confirmed SARS-CoV-2-infected patients, between 1 February and 25 April 2022 (Omicron dominant era). SARS-CoV-2 S1-specific IgG antibody titers were measured using enzyme-linked immunosorbent assay (ELISA). Plasma levels of live-virus neutralizing antibodies were measured using a microneutralization assay with SARS-CoV-2 omicron variants. Results Among 134 HCWs, 69 (52%) received two-dose ChAdOx1 nCoV-19 followed by BNT162b2, 50 (37%) three-dose BNT162b2, and 15 (11%) 3-dose mRNA-1273. Of them, 57 (43%) experienced breakthrough Omicron infection at median 121 days (IQR 99-147) after booster vaccination (breakthrough group), and the remaining 77 (57%) did not experience Omicron infection (non-breakthrough group). There was no significant different in “peak” SARS-CoV-2 S1-specific IgG level between breakthrough group (median 4484.4 IU/mL) and non-breakthrough group (median 4194.9 IU/mL, p value=0.39). In addition, there was no significant difference in “peak” neutralizing antibody titer (ID50) against Omicron between breakthrough group (median 2597.9) and non-breakthrough group (median 2597.9, p value=0.86). Figure 1.Comparison of S1-specific IgG antibody and neutralizing antibody titer between breakthrough group and non-breakthrough group Serum samples were obtained from 134 healthcare workers 2 weeks after booster vaccination. Samples were analysed for SARS-CoV-2 S1-specific IgG antibody titers using enzyme-linked immunosorbent assay (ELISA) and plasma levels of live-virus neutralizing antibodies using a microneutralization assay with SARS-CoV-2 omicron variants. There was no significant difference in "peak" SARS-CoV-2 S1-specific IgG level (A) and “peak” neutralizing antibody titer (ID50) against Omicron (B) between breakthrough group and non-breakthrough group. Conclusion We did not find the correlation of neutralizing antibody titers about several months before infection with breakthrough Omicron infections. These data suggest rapidly waning neutralizing titers to protect mild illnesses or asymptomatic Omicron infections several months after current booster COVID-19 vaccination in HCWs. Disclosures All Authors: No reported disclosures.

Evaluation of anti-spike IgG response after inactivated COVID-19 vaccine in healthcare workers

Aim: This study purposed to determine anti-spike IgG levels at the fourth week after the second dose in healthcare workers (HCWs) who had two doses of the CoronaVac vaccine (Sinovac Life Sciences, Beijing, China). The second purpose of the study was to evaluate several factors that may affect antibody levels.
 Material and Method: The study was performed at Kastamonu Training and Research Hospital. A total of 197 HCWs of both genders aged 20-63 were included in this study. Antibody levels that neutralize the SARS-CoV-2 spike protein S1 subunit were determined using the SARS-CoV-2 IgG II Quant kit from serum samples collected from the subjects between 10-16 March 2021. Also, a questionnaire containing information about demographic and clinical data was administered to all subjects. It was statistically investigated whether these data affected the anti-spike IgG levels.
 Results: All subjects had anti-spike IgG levels positive. The median value of the subjects' anti-spike IgG levels was calculated as 860.2 AU/mL (519.1-1674.1 AU/mL). Anti-spike IgG levels were statistically higher in non-smokers and Rh-positive subjects versus the smokers and Rh-negative subjects (p=0.001 and p=0.046, respectively). However, age groups, gender, COVID-19 history, blood type, and seasonal influenza vaccine did not significantly affect anti-spike IgG levels in the subjects (p>0.05).
 Conclusion: Anti-spike IgG responses were positive in all HCWs who received the CoronaVac vaccine. Besides, the results showed that smoking and Rh-factor affect the anti-spike IgG response. On the other hand, further studies need to examine more parameters with a larger number of subjects.

Adverse Effects of Third-Dose Moderna Vaccination for Healthcare Workers of Udayana University Hospital, Bali, Indonesia

ABSTRACT. 
 Background
 Since its first sighting in China at the end of 2019, COVID-19 had spread rapidly around the world, with no exception, to Indonesia. World Health Organization officially declared COVID-19 as a pandemic in March 2020. COVID-19 causes severe symptoms for those immunocompromised, making it an urgent matter to end the pandemic as soon as possible. In only 1 year since COVID-19 was found, the world has successfully developed COVID-19 vaccines which experts believe may bring an end to the pandemic. However, the vaccination also carries risk of adverse effect. 
 Aim
 The aim of this study is to report how the adverse effect of third dose mRNA-1273 vaccine in healthcare workers at Udayana University Hospital.
 Methods
 The descriptive study collects data from all healthcare workers in Udayana University Hospital receiving third-dose mRNA-1273 vaccine using online questionnaires. We excluded incomplete responds to maintain quality of data. This report comprises demographic characteristics, clinical history, and the adverse effects and was approved by the ethical committee of Udayana University.
 Result
 We received a respond rate of 86.9% (N=553) from a total of 636 healthcare workers who received the third-dose mRNA-1273 vaccine. Our respondents had a mean age of 37 (SD ± 7.81) years old. Most were female (55.8%) aging 20-29 years old (57.1%), and had an interval between their initial and third dose between 3-5 months (53.4%). Adverse effect most recorded was local pain (82.8%), followed by fever (56.4%), weakness/fatigue (39.3%), excessive sleepiness (32.5%), dizziness (30.1%), headache (27.6%), nausea/vomiting (21.5%), excessive hungerness (18,4%), other symptoms (11.0%) and local erythema (10.4%). About 39.9% of the respondents felt the adverse effect 12-24 hours post-vaccination. 
 Conclusion
 Adverse effects following third-dose mRNA-1273 vaccination in healthcare workers of Udayana University Academic Hospital includes local pain, fever, weakness/fatigue, excessive sleepiness, dizziness, headache, nausea and vomiting, excessive hunger, and local erythema. Most of these symptoms occurred within the first 24 hours post-vaccination.
 
 Key Words: Vaccine, Adverse Effect, mRNA-1273, COVID-19, Healthcare Worker

Vaccinated Healthcare Workers' Adherence to COVID-19 Prevention Measures and Associated Factors in Northwest Ethiopia: A Facility-Based Cross-Sectional Study.

The initial response to coronavirus disease 2019 (COVID-19) was non-pharmaceutical interventions (NPIs). Long-term protection against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection does not appear to be possible by either infection or vaccination. Thus, traditional herd immunity seems impossible. In addition to increasing vaccination rates, NPIs may be needed. A facility-based cross-sectional study was conducted among vaccinated healthcare workers. The study took place from July 15 to August 15, 2022. A self-administered questionnaire was used for data collection. In a multivariable logistic regression model, a p-value of less than 0.05 was considered statistically significant. Four hundred eleven healthcare workers were included in the study. Sixty percent of participants were fully vaccinated. After vaccination, 10.2% of respondents reported infection with SARS-CoV-2. The study showed that 49.4% of participants had a good knowledge of the efficacy and safety of vaccines against SARS-CoV-2. In this study, 36% of individuals adhered well to the COVID-19 prevention strategies. Good knowledge of the efficacy and safety of SARS-CoV-2 vaccines (AOR = 1.69, 95% CI: 1.03-2.78) increased the odds of implementing preventive measures. Healthcare workers who perceived a low and medium risk of SARS-CoV-2 infection after vaccination and who were knowledgeable about SARS-CoV-2 breakthrough infections were less likely to follow preventive measures. The knowledge of healthcare workers regarding the efficacy and safety of vaccines against SARS-CoV-2 was comparable. However, a large proportion of healthcare workers poorly adhered to prevention practices. Therefore, to reduce the risk of SARS-CoV-2 infection among healthcare professionals, prevention strategies must be continuously evaluated and awareness of the need for preventive measures must be raised even after vaccination.

Medical Residents' Behaviours toward Compulsory COVID-19 Vaccination in a Tertiary Hospital in Italy.

To maintain safety conditions in the provision of care and assistance, and to protect healthcare workers (HCWs) and patients, the Italian government required compulsory COVID-19 vaccination for HCWs, including medical residents (MRs). The aim of this study was to assess COVID-19 vaccination coverage in MRs in a large tertiary hospital in Italy, before and after the introduction of compulsory vaccination, according to demographic characteristics and specific residency. A database on COVID-19 vaccination status and infection of resident medical doctors was created. Descriptive statistics and logistic regressions were carried out on the data. A total of 1894 MRs were included in the study. Being vaccinated in the same hospital as the residency program was significantly related to the year of residency and being enrolled in a frontline residency. A significant association between compliance with the compulsory primary cycle vaccination and vaccination in the hospital residency was observed. Being enrolled in the second, third, and last years of residency, and in a frontline residency, were predictive of being vaccinated in the residency hospital. Almost 100% of the MRs participating in the study were vaccinated against COVID-19. Compulsory vaccination of HCWs, alongside greater and clearer information about the risks and benefits of vaccination, represents an important booster to ensure public health and to promote quality and safety of care.

SARS-CoV-2 Specific Humoral Immune Responses after BNT162b2 Vaccination in Hospital Healthcare Workers.

COVID-19 pandemic has led to a loss of human life in millions and devastating socio-economic consequences worldwide. So far, vaccination is the most effective long-term strategy to control and prevent severe COVID-19 disease. The aim of the current study was to evaluate the humoral immune responses raised against the BNT162b2 vaccine in hospital healthcare workers. Total number of 173 healthcare workers enrolled in the study. Their blood samples were collected in three different time intervals after the second SARS-CoV-2 vaccination and evaluated by the ELISA method to detect anti-spike protein IgM and IgG antibodies. The baseline characteristics of all participants were collected using questionnaires and were evaluated for finding any significant data. Our results demonstrated that the levels of antibodies were higher in the young group (21-30 years old) and also among male participants. Moreover, the highest levels of antibodies were detected from the group that received the third shot vaccination. Our results indicate that age, gender and third-dose vaccination can affect the levels of humoral immune responses against the BNT162b2 vaccine in healthcare workers.

Comparative Effectiveness of Mask Type in Preventing SARS-CoV-2 in Health Care Workers: Uncertainty Persists.

Comparative Effectiveness of Mask Type in Preventing SARS-CoV-2 in Health Care Workers: Uncertainty Persists.

Antibody Titer Correlates with Omicron Infection in Vaccinated Healthcare Workers.

The advent of vaccines against SARS-CoV-2 has drastically reduced the level of hospitalization with severe COVID-19 disease in infected individuals. However, the diffusion of variants of concern still challenge the protection conferred by vaccines raised against the wild-type form of the virus. Here, we have characterized the antibody response to the BNT162b2 (Comirnaty) mRNA vaccine in patients infected with the Omicron variant. We analyzed a population of 4354 vaccinated healthcare workers (HCW) from 7 different hospitals in Italy and monitored infection with SARS-CoV-2 Omicron. We correlated infection with the antibody response after vaccination. We found that a lower level of IgG, younger age, and the presence of allergies correlate with increased infection during the Omicron wave, and that infections correlate with wild-type spike protein antibody titers below 350 BAU/mL. These results support the necessity of a fourth booster dose, particularly for individuals with lower levels of antibodies.

Genetic Sequencing of Breakthrough Severe Acute Respiratory Syndrome Coronavirus 2 Infections in Fully Vaccinated Healthcare Workers

Abstract Introduction Since the identification of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), several efforts have been made to prevent infection, culminating in the development of highly effective vaccines. However, as genetic variants of the virus have emerged, concerns have arisen regarding potential limitations of available vaccines. Methods In this article, we evaluated SARS-CoV-2 breakthrough infections among 520 healthcare workers in a 950-bed hospital from March 1, 2021, to October 31, 2021, and stratified them according to the type of vaccine received. We tested for associations between Alpha and Delta strains of SARS-CoV-2 and clinical characteristics. Results During the study period, only 0.85% of the patients with breakthrough infection vaccinated with messenger RNA (mRNA)-1273 required hospitalization, whereas none of patients vaccinated with BNT162b2 required admission. No association was noted between the variant isolated and the type of vaccination (P = 0.474). The cycle threshold was significantly lower for Delta strain infections compared with Alpha strain infections (P = 0.0144 for gene N1 and P = 0.0271 for gene N2), reflecting a significantly higher viral burden at the time of diagnosis of Delta strain infection. We observed that, at the time of diagnosis, almost all vaccinated patients had developed antispike antibodies, whereas slightly more than half had anti-N antibodies. Discussion We noted that vaccination remains an important preventive measure to protect patients from severe SARS-CoV-2 infection. The mRNA-1273 and BNT162b2 mRNA vaccines seem equally effective in minimizing the severity of breakthrough infections. Serologic patterns suggest that antispike antibodies may be more critical for protection than antinucleocapsid antibodies.

The Italian policy of mandating SARS-CoV-2 vaccination for healthcare workers: Analysis of the policy processes and preliminary outcomes

BackgroundItaly experienced the first outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Europe, and was among the most hardly hit European countries. Growing evidence suggests healthcare workers (HCWs) are at increased risk of SARS-CoV-2 infection. Infection in HCWs can lead to cross-transmission and increase community transmission. Italy was the first country in Europe to introduce mandatory vaccinations against SARS-CoV-2 for HCWs, on April 1, 2021. AimTo describe the policy processes and preliminary results of the introduction of compulsory vaccination against SARS-CoV-2 for HCWs in Italy. Results and conclusionIn Italy, the adoption of the policy was possible in the context of the public health and economic crisis resulting from the pandemic, with support from the scientific community and among favorable political conditions. Preliminary data suggest the policy has so far had a positive impact on increasing vaccine uptake and lowering infection rates among HCWs. Hopefully, the lack of serious vaccine-related adverse events and the growing evidence on vaccine effectiveness will progressively strengthen vaccine confidence among HCWs. In the context of a global pandemic, the Italian experience could provide insight for policymakers in other countries considering similar policies. Further, the ethical, legal, and policy challenges raised by the current public health emergency could be used to inform future pandemic preparedness plans.

Strategic silences, eroded trust: The impact of divergent COVID-19 vaccine sentiments on healthcare workers' relations with peers and patients.

BackgroundPolarized debates about Covid-19 vaccination and vaccine mandates for healthcare workers (HCWs) challenge Belgian HCWs ability to discuss Covid-19 vaccine sentiments with peers and patients. Although studies have identified drivers of HCWs vaccine hesitancy, they do not include effects of workplace interactions and have not addressed consequences beyond vaccine coverage.MethodsInterviews and focus group discussions with 73 HCWs practicing in Belgium addressed Covid-19 vaccine sentiments and experiences of discussing vaccination with peers and patients.ResultsMost participating HCWs reported difficulties discussing Covid-19 vaccination with peers and patients. Unvaccinated HCWs often feared that expressing their vaccine sentiments might upset patients or peers and that they would be suspended. Consequently, they used social cues to evaluate others’ openness to vaccine-skeptical discourses and avoided discussing vaccines. Surprisingly, some vaccine-confident HCWs hid their vaccine sentiments to avoid peer and patient conflicts. Both vaccinated and unvaccinated HCWs observed that unvaccinated patients occasionally received suboptimal care. Suboptimal care was central in unvaccinated HCW unwillingness to express their vaccine sentiments to peers. Both vaccinated and unvaccinated HCWs described loss of trust and ruptured social relations with peers and patients holding divergent vaccine sentiments.DiscussionBelgian HCW perceived Covid-19 vaccines as a risky discussion topic and engaged in “strategic silences” around vaccination to maintain functional work relationships and employment in health institutions. Loss of trust between HCW and peers or patients, along with suboptimal patient care based on vaccination status, threaten to weaken Belgium’s, and by implication, other health systems, and to catalyze preventable disease outbreaks.

Effectiveness of COVID-19 vaccination in healthcare workers in Shiga Prefecture, Japan

This study, which included serological and cellular immunity tests, evaluated whether coronavirus disease 2019 (COVID-19) vaccination adequately protected healthcare workers (HCWs) from COVID-19. Serological investigations were conducted among 1600 HCWs (mean ± standard deviation, 7.4 ± 1.4 months after the last COVID-19 vaccination). Anti-SARS-CoV-2 antibodies N-Ig, Spike-Ig (Roche), N-IgG, Spike-IgM, and -IgG (Abbott), were evaluated using a questionnaire of health condition. 161 HCWs were analyzed for cellular immunity using T-SPOT® SARS-CoV-2 kit before, and 52 HCWs were followed up until 138.3 ± 15.7 days after their third vaccination. Spike-IgG value was 954.4 ± 2282.6 AU/mL. Forty-nine of the 1600 HCWs (3.06%) had pre-existing SARS-CoV-2 infection. None of the infectious seropositive HCWs required hospitalization. T-SPOT value was 85.0 ± 84.2 SFU/106 cells before the third vaccination, which increased to 219.4 ± 230.4 SFU/106 cells immediately after, but attenuated later (to 111.1 ± 133.6 SFU/106 cells). Poor counts (< 40 SFU/106 cells) were present in 34.8% and 38.5% of HCWs before and after the third vaccination, respectively. Our findings provide insights into humoral and cellular immune responses to repeated COVID-19 vaccinations. COVID-19 vaccination was effective in protecting HCWs from serious illness during the original Wuhan-1, Alpha, Delta and also ongoing Omicron-predominance periods. However, repeated vaccinations using current vaccine versions may not induce sufficient cellular immunity in all HCWs.

Serum neutralization of SARS coronavirus 2 Omicron sublineages BA.1 and BA.2 and cellular immune responses 3 months after booster vaccination

ObjectivesWe investigated serum neutralizing activity against BA.1 and BA.2 Omicron sublineages and T cell response before and 3 months after administration of the booster vaccine in healthcare workers (HCWs). MethodsHCWs aged 18–65 years who were vaccinated and received booster doses of the BNT162b2 vaccine were included. Anti–SARS coronavirus 2 IgG levels and cellular response (through interferon γ ELISpot assay) were evaluated in all participants, and neutralizing antibodies against Delta, BA.1, and BA.2 were evaluated in participants with at least one follow-up visit 1 or 3 months after the administration of the booster dose. ResultsAmong 118 HCWs who received the booster dose, 102 and 84 participants attended the 1-month and 3-month visits, respectively. Before the booster vaccine dose, a low serum neutralizing activity against Delta, BA.1, and BA.2 was detectable in only 39/102 (38.2%), 8/102 (7.8%), and 12/102 (11.8%) participants, respectively. At 3 months, neutralizing antibodies against Delta, BA.1, and BA.2 were detected in 84/84 (100%), 79/84 (94%), and 77/84 (92%) participants, respectively. Geometric mean titres of neutralizing antibodies against BA.1 and BA.2 were 2.2-fold and 2.8-fold reduced compared with those for Delta. From 1 to 3 months after the administration of the booster dose, participants with a recent history of SARS coronavirus 2 infection (n = 21/84) had persistent levels of S1 reactive specific T cells and neutralizing antibodies against Delta and BA.2 and 2.2-fold increase in neutralizing antibodies against BA.1 (p 0.014). Conversely, neutralizing antibody titres against Delta (2.5-fold decrease, p < 0.0001), BA.1 (1.5-fold, p 0.02), and BA.2 (2-fold, p < 0.0001) declined from 1 to 3 months after the administration of the booster dose in individuals without any recent infection. DiscussionThe booster vaccine dose provided significant and similar response against BA.1 and BA.2 Omicron sublineages; however, the immune response declined in the absence of recent infection.

The Economic and Fiscal Impact of Influenza Vaccination for Health Care Workers in Italy.

Influenza has a significant impact on the health care system and also on production and economic systems. Vaccinated health care workers (HCWs) are more likely to have improved productivity compared to unvaccinated workers. The study aim was to estimate the economic and fiscal impact of an influenza vaccination program for HCWs in Italy. We performed a cost analysis aimed to estimate the indirect costs (productivity losses due to working days lost) and the increase in tax revenues derived from the increase in vaccination coverage among HCWs. Assuming an incremental increase in vaccination coverage of 10% per year over a period of 5 years, total savings could be obtained in terms of a reduction in productivity losses equal to −€4,475,497.16 and an increase in tax revenues of €327,158.84. This revenue could be used to finance other health interventions. Our results are fundamental in view of the sustainability of health systems and of a value-based allocation of health resources. Therefore, a complete social perspective, including the fiscal impact of flu vaccination, should be adopted to assess the economic value of influenza vaccines. Currently, health policies based on the whole value of flu vaccination are needed.

SEMI-QUANTITATIVE ANALYSIS OF SARS-COV-2 IGG ANTIBODIES FOLLOWING CHADOX1-NCOV (COVISHIELD™) VACCINATION

Objectives: The objectives of this study were semi-quantitatively analyze SARS-COV-2 IgG antibodies following covishield vaccination in healthcare workers and to follow-up them for 6 months for persistence of antibodies and for getting infected with SARS-COV-2. Methods: This was a prospective cohort study which was conducted at tertiary care hospital, South India. The blood samples were collected after second dose of vaccine at 28 days, 60 days, and 120 days. The serum was subjected for detection of IgG antibodies against S1 RBD (Receptor binding domain) of the spike protein antigen by Euroimmun kit (PerkinElmer company, Germany) using ELISA. Results: Out of 30 healthcare workers, 28 (93.3%) were seropositive and 2 (6.7%) were seronegative. Out of two seronegative, one participant acquired SARS-COV-2 infection with severe symptoms. There was approximately 50% reduction in antibody levels in almost all seropositive individuals after 3 months of second dose. Even after 6 months, 25 (83.3%) were seropositive, 2 (6.7%) were seronegative, and 3 (10%) were borderline. When the IgG antibody ratio levels of 28 days following second dose of vaccination were compared with levels after 6 months, which showed, p value of 0.024 which is &lt;0.05 implies statistically significant. Conclusion: Covishield vaccine induced good immune response in majority of the participants, the levels were sustainably positive until 6 months but decreasing pattern. The vaccine-induced antibodies prevented the severe symptoms among vaccine breakthrough infections.