Primary Series COVID-19 Vaccine Effectiveness among Health Care Workers in Albania, February–December 2021

Background Healthcare workers have experienced high rates of morbidity and mortality from COVID-19. Methods We conducted a prospective cohort study in three Albanian hospitals between February 19 and December 14, 2021. All participants underwent PCR and serology testing at enrolment, regular serology throughout, and PCR testing when symptomatic. We estimated vaccine effectiveness (VE) against COVID-19, and against all SARS-CoV-2 infections (symptomatic or asymptomatic). VE was estimated using a Cox regression model, with vaccination status as a time-varying variable. Findings We enrolled 1504 HCWs;70% had evidence of prior SARS-CoV-2 infection. VE against COVID-19 was 65·1% (95% CI 37·7–80·5);58·2% (95% CI 15·7–79·3) among participants without prior SARS-CoV-2 infection;and 73·6% (95% CI 24·3–90·8) among previously-infected participants. For BNT162b2 only, VE was 69·5% (95% CI 44·5–83·2). During the Delta variant-predominant period, VE was 67·1% (95% CI 38·3–82·5). VE against SARS-CoV-2 infection for the full study period was 36·9% (95% CI 15·8–52·7). Interpretation We found moderate primary-series VE against COVID-19 among healthcare workers in Albania. Our results support the continued promotion of COVID-19 vaccine in Albania, and highlight the benefit of vaccination in populations with high levels of prior infection.

Factors associated with receipt of COVID-19 vaccination and SARS-CoV-2 seropositivity among healthcare workers in Albania (February 2021–June 2022): secondary analysis of a prospective cohort study

Background Healthcare workers (HCWs) have been disproportionally affected by COVID-19. We investigated factors associated with two- and three-dose COVID-19 vaccine uptake and SARS-CoV-2 seropositivity among 1504 HCWs enrolled (19 February-7 May 2021) in a prospective COVID-19 vaccine effectiveness cohort in Albania through a secondary analysis. Methods We collected sociodemographic, occupational, health, prior SARS-CoV-2 infection, and COVID-19 vaccination data from all HCWs at enrollment. Vaccination status was assessed weekly through June 2022. A serum sample was collected from all participants at enrollment and tested for anti-spike SARS-CoV-2 antibodies. We analyzed HCWs characteristics and outcomes using multivariable logistic regression. Findings By 11 June 2022, 1337 (88.9%) HCWs had received two COVID-19 vaccine doses, of whom 255 (19.1%) received a booster. Factors significantly associated with receiving three doses (adjusted odds ratio (aOR), 95% CIs) were being ≥35 years (35–44 years: 1.76 (1.05–2.97);45–54 years: 3.11 (1.92–5.05);≥55 years: 3.38 (2.04–5.59)) and vaccinated against influenza (1.78;1.20–2.64). Booster dose receipt was lower among females (0.58;0.41–0.81), previously infected (0.67;0.48–0.93), nurses and midwives (0.31;0.22–0.45), and support staff (0.19;0.11–0.32). Overall 1076 (72%) were SARS-CoV-2 seropositive at enrollment. Nurses and midwifes (1.45;1.05–2.02), support staff (1.57;1.03–2.41), and HCWs performing aerosol-generating procedures (AGPs) (1.40;1.01–1.94) had higher odds of being seropositive, while smokers had reduced odds (0.55;0.40–0.75). Interpretation In a large cohort of Albanian HCWs, COVID-19 vaccine booster dose uptake was very low, particularly among younger, female, and non-physician HCWs, despite evidence demonstrating the added benefit of boosters in preventing infection and severe disease. Reasons behind these disparities should be explored to develop targeted strategies in order to promote uptake in this critical population. SARS-CoV-2 seroprevalence was higher among non-physicians and HCWs performing APGs. A better understanding of the factors contributing to these differences is needed to inform interventions that could reduce infections in the future. Funding This study was funded by the Task Force for 10.13039/100006090Global Health (10.13039/100000030US Centers for Disease Control (CDC) cooperative agreement # NU51IP000873) and the World Health Organization, Regional Office for Europe.

Factors associated with receipt of COVID-19 vaccination and SARS-CoV-2 seropositivity among healthcare workers in Albania (February 2021-June 2022): secondary analysis of a prospective cohort study.

Background: Healthcare workers (HCWs) have been disproportionally affected by COVID-19. We investigated factors associated with two- and three-dose COVID-19 vaccine uptake and SARS-CoV-2 seropositivity among 1504 HCWs enrolled (19 February-7 May 2021) in a prospective COVID-19 vaccine effectiveness cohort in Albania through a secondary analysis. Methods: We collected sociodemographic, occupational, health, prior SARS-CoV-2 infection, and COVID-19 vaccination data from all HCWs at enrollment. Vaccination status was assessed weekly through June 2022. A serum sample was collected from all participants at enrollment and tested for anti-spike SARS-CoV-2 antibodies. We analyzed HCWs characteristics and outcomes using multivariable logistic regression. Findings: By 11 June 2022, 1337 (88.9%) HCWs had received two COVID-19 vaccine doses, of whom 255 (19.1%) received a booster. Factors significantly associated with receiving three doses (adjusted odds ratio (aOR), 95% CIs) were being ≥35 years (35-44 years: 1.76 (1.05-2.97); 45-54 years: 3.11 (1.92-5.05); ≥55 years: 3.38 (2.04-5.59)) and vaccinated against influenza (1.78; 1.20-2.64). Booster dose receipt was lower among females (0.58; 0.41-0.81), previously infected (0.67; 0.48-0.93), nurses and midwives (0.31; 0.22-0.45), and support staff (0.19; 0.11-0.32). Overall 1076 (72%) were SARS-CoV-2 seropositive at enrollment. Nurses and midwifes (1.45; 1.05-2.02), support staff (1.57; 1.03-2.41), and HCWs performing aerosol-generating procedures (AGPs) (1.40; 1.01-1.94) had higher odds of being seropositive, while smokers had reduced odds (0.55; 0.40-0.75). Interpretation: In a large cohort of Albanian HCWs, COVID-19 vaccine booster dose uptake was very low, particularly among younger, female, and non-physician HCWs, despite evidence demonstrating the added benefit of boosters in preventing infection and severe disease. Reasons behind these disparities should be explored to develop targeted strategies in order to promote uptake in this critical population. SARS-CoV-2 seroprevalence was higher among non-physicians and HCWs performing APGs. A better understanding of the factors contributing to these differences is needed to inform interventions that could reduce infections in the future. Funding: This study was funded by the Task Force for Global Health (US Centers for Disease Control (CDC) cooperative agreement # NU51IP000873) and the World Health Organization, Regional Office for Europe.

Sociodemographic and Occupational Factors Associated with Low Early Uptake of COVID-19 Vaccine in Hospital-Based Healthcare Workers, Georgia, March-July 2021.

In Georgia, an upper-middle income European country, the COVID-19 vaccine rollout began on 15 March 2021 with health workers (HWs), a priority group for vaccination. We assessed the factors associated with COVID-19 vaccination among HWs at six large hospitals in the early stages of the vaccine rollout (March-July 2021). Among 1533 HWs, 274 (17.9%) had received one dose of the COVID-19 vaccine. Strong independent predictors of early vaccine uptake were age > 40 years, especially 50-59 years old (aOR 2.40, 95% CI 1.50-3.88), considering the vaccine as "somewhat effective" or "very effective" rather than "not effective" (aOR 6.33, 95% CI 2.29-26.3 and aOR 10.9, 95% CI 3.88-45.70, respectively), and previous vaccination against seasonal influenza (aOR 2.98, 95% CI 2.19-4.08). Previous SARS-CoV-2 infection was negatively associated with receiving the vaccine (aOR 0.6, 95% CI 0.40-0.80). Compared to physicians, nurses/midwives (aOR 0.22, 95% CI 0.15-0.32), administrative staff (aOR 0.36, 95% CI 0.22-0.56), and ancillary staff (aOR 0.07, 95% CI 0.04-0.15) were less likely to have received the COVID-19 vaccine. Tailoring the COVID-19 vaccine communications campaign to younger and non-physician HWs, and emphasizing the benefits of the COVID-19 vaccine, could help further increase vaccine coverage among HWs in Georgia.

COVID-19 vaccine effectiveness among healthcare workers in Albania (COVE-AL): protocol for a prospective cohort study and cohort baseline data.

INTRODUCTION: Critical questions remain about COVID-19 vaccine effectiveness (VE) in real-world settings, particularly in middle-income countries. We describe a study protocol to evaluate COVID-19 VE in preventing laboratory-confirmed SARS-CoV-2 infection in health workers (HWs) in Albania, an upper-middle-income country. METHODS AND ANALYSIS: In this 12-month prospective cohort study, we enrolled HWs at three hospitals in Albania. HWs are vaccinated through the routine COVID-19 vaccine campaign. Participants completed a baseline survey about demographics, clinical comorbidities, and infection risk behaviours. Baseline serology samples were also collected and tested against the SARS-CoV-2 spike protein, and respiratory swabs were collected and tested for SARS-CoV-2 by RT-PCR. Participants complete weekly symptom questionnaires and symptomatic participants have a respiratory swab collected, which is tested for SARS-CoV-2. At 3, 6, 9 months and 12 months of the study, serology will be collected and tested for antibodies against the SARS-CoV-2 nucleocapsid protein and spike protein. VE will be estimated using a piecewise proportional hazards model (VE=1-HR). BASELINE DATA: From February to May 2021, 1504 HWs were enrolled. The median age was 44 (range: 22-71) and 78% were female. At enrolment, 72% of participants were seropositive for SARS-CoV-2. 56% of participants were vaccinated with one dose, of whom 98% received their first shot within 4 days of enrolment. All HWs received the Pfizer BNT162b2 mRNA COVID-19 vaccine. ETHICS AND DISSEMINATION: The study protocol and procedures were reviewed and approved by the WHO Ethical Review Board, reference number CERC.0097A, and the Albanian Institute of Public Health Ethical Review Board, reference number 156. All participants have provided written informed consent to participate in this study. The primary results of this study will be published in a peer-reviewed journal at the time of completion. TRIAL REGISTRATION NUMBER: NCT04811391.

Factors associated with early uptake of COVID-19 vaccination among healthcare workers in Azerbaijan, 2021.

INTRODUCTION: We evaluated uptake and factors associated with COVID-19 vaccination among health workers (HWs) in Azerbaijan. RESULTS: Among 1575 HWs, 73% had received at least one dose, and 67% received two doses; all received CoronaVac. Factors associated with vaccination uptake included no previous COVID-19 infection, older age, belief in the vaccine's safety, previous vaccination for influenza, having patient-facing roles and good or excellent health by self-assessment. CONCLUSION: These findings could inform strategies to increase vaccination uptake as the campaign continues.

Early effectiveness of BNT162b2 Covid-19 vaccine in preventing SARS-CoV-2 infection in healthcare personnel in six Israeli hospitals (CoVEHPI).

BACKGROUND: Methodologically rigorous studies on Covid-19 vaccine effectiveness (VE) in preventing SARS-CoV-2 infection are critically needed to inform national and global policy on Covid-19 vaccine use. In Israel, healthcare personnel (HCP) were initially prioritized for Covid-19 vaccination, creating an ideal setting to evaluate early real-world VE in a closely monitored population. METHODS: We conducted a prospective study among HCP in 6 hospitals to estimate the effectiveness of the BNT162b2 mRNA Covid-19 vaccine in preventing SARS-CoV-2 infection. Participants filled out weekly symptom questionnaires, provided weekly nasal specimens, and three serology samples - at enrollment, 30 days and 90 days. We estimated VE against PCR-confirmed SARS-CoV-2 infection using the Cox Proportional Hazards model and against a combined PCR/serology endpoint using Fisher's exact test. RESULTS: Of the 1567 HCP enrolled between December 27, 2020 and February 15, 2021, 1250 previously uninfected participants were included in the primary analysis; 998 (79.8%) were vaccinated with their first dose prior to or at enrollment, all with Pfizer BNT162b2 mRNA vaccine. There were four PCR-positive events among vaccinated participants, and nine among unvaccinated participants. Adjusted two-dose VE against any PCR-confirmed infection was 94.5% (95% CI: 82.6%-98.2%); adjusted two-dose VE against a combined endpoint of PCR and seroconversion for a 60-day follow-up period was 94.5% (95% CI: 63.0%-99.0%). Five PCR-positive samples from study participants were sequenced; all were alpha variant. CONCLUSIONS: Our prospective VE study of HCP in Israel with rigorous weekly surveillance found very high VE for two doses of Pfizer BNT162b2 mRNA vaccine against SARS-CoV-2 infection in recently vaccinated HCP during a period of predominant alpha variant circulation. FUNDING: Clalit Health Services.

Evaluation of post-introduction COVID-19 vaccine effectiveness: Summary of interim guidance of the World Health Organization.

Phase 3 randomized-controlled trials have provided promising results of COVID-19 vaccine efficacy, ranging from 50 to 95% against symptomatic disease as the primary endpoints, resulting in emergency use authorization/listing for several vaccines. However, given the short duration of follow-up during the clinical trials, strict eligibility criteria, emerging variants of concern, and the changing epidemiology of the pandemic, many questions still remain unanswered regarding vaccine performance. Post-introduction vaccine effectiveness evaluations can help us to understand the vaccine's effect on reducing infection and disease when used in real-world conditions. They can also address important questions that were either not studied or were incompletely studied in the trials and that will inform evolving vaccine policy, including assessment of the duration of effectiveness; effectiveness in key subpopulations, such as the very old or immunocompromised; against severe disease and death due to COVID-19; against emerging SARS-CoV-2 variants of concern; and with different vaccination schedules, such as number of doses and varying dosing intervals. WHO convened an expert panel to develop interim best practice guidance for COVID-19 vaccine effectiveness evaluations. We present a summary of the interim guidance, including discussion of different study designs, priority outcomes to evaluate, potential biases, existing surveillance platforms that can be used, and recommendations for reporting results.

"You Have to Die Not to Come to Work": A Mixed Methods Study of Attitudes and Behaviors regarding Presenteeism, Absenteeism and Influenza Vaccination among Healthcare Personnel with Respiratory Illness in Israel, 2016-2019.

INTRODUCTION: Healthcare personnel (HCP) have an increased risk of exposure to influenza and other respiratory pathogens. Increased presenteeism, decreased absenteeism, and low uptake of the influenza vaccine can contribute to the spread of influenza among HCP in healthcare settings. We used a mixed methods approach to investigate attitudes and behaviors of HCP in Israel towards influenza vaccination, presenteeism, and absenteeism. METHODS: The study took place over three influenza seasons (2016-2017, 2017-2018, 2018-2019) at the largest hospital in southern Israel. We administered a Knowledge, Attitudes and Practices (KAP) questionnaire and conducted semi-structured interviews with HCP who had been recently ill with respiratory symptoms. The KAP questionnaire included closed-ended questions about attitudes and behaviors regarding influenza, working while sick, and influenza vaccination. The interviews investigated HCP's perceptions of influenza infection and attitudes about absenteeism, presenteeism, and the influenza vaccine. RESULTS: We conducted 74 semi-structured interviews over three influenza seasons. Four HCP were interviewed twice, in separate seasons for different illness episodes. The 70 individuals interviewed included 16 physicians, 45 nurses or technicians, and 9 administrative staff. The median age was 42.5 years (range: 25-60), and most (79%) were female. Half (50%) got vaccinated against influenza before their illness episode. In interviews, most HCP said they come to work while sick (presenteeism) due to a strong personal work ethic and an institutional culture that discourages taking sick leave (absenteeism). HCP expressed skepticism about the effectiveness of the influenza vaccine as well as concern that the influenza vaccine causes severe illness. DISCUSSION: Over three influenza seasons in Israel, HCP cited a number of reasons for working while sick, and doubted the usefulness of influenza vaccine. Addressing reasons for presenteeism and vaccine hesitancy among HCP is crucial to protect HCP and patients from influenza virus infection and other viral respiratory illnesses, such as COVID-19.

BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting.

BACKGROUND: As mass vaccination campaigns against coronavirus disease 2019 (Covid-19) commence worldwide, vaccine effectiveness needs to be assessed for a range of outcomes across diverse populations in a noncontrolled setting. In this study, data from Israel's largest health care organization were used to evaluate the effectiveness of the BNT162b2 mRNA vaccine. METHODS: All persons who were newly vaccinated during the period from December 20, 2020, to February 1, 2021, were matched to unvaccinated controls in a 1:1 ratio according to demographic and clinical characteristics. Study outcomes included documented infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), symptomatic Covid-19, Covid-19-related hospitalization, severe illness, and death. We estimated vaccine effectiveness for each outcome as one minus the risk ratio, using the Kaplan-Meier estimator. RESULTS: Each study group included 596,618 persons. Estimated vaccine effectiveness for the study outcomes at days 14 through 20 after the first dose and at 7 or more days after the second dose was as follows: for documented infection, 46% (95% confidence interval [CI], 40 to 51) and 92% (95% CI, 88 to 95); for symptomatic Covid-19, 57% (95% CI, 50 to 63) and 94% (95% CI, 87 to 98); for hospitalization, 74% (95% CI, 56 to 86) and 87% (95% CI, 55 to 100); and for severe disease, 62% (95% CI, 39 to 80) and 92% (95% CI, 75 to 100), respectively. Estimated effectiveness in preventing death from Covid-19 was 72% (95% CI, 19 to 100) for days 14 through 20 after the first dose. Estimated effectiveness in specific subpopulations assessed for documented infection and symptomatic Covid-19 was consistent across age groups, with potentially slightly lower effectiveness in persons with multiple coexisting conditions. CONCLUSIONS: This study in a nationwide mass vaccination setting suggests that the BNT162b2 mRNA vaccine is effective for a wide range of Covid-19-related outcomes, a finding consistent with that of the randomized trial.