Delay between COVID-19 complete vaccination and SARS-CoV-2 infection among healthcare workers

SARS-CoV-2 infection after COVID-19 vaccinations among vaccinated individuals, prevention rate of COVID-19 vaccination: A systematic review and meta-analysis

Background

The global concern regarding protection against the COVID-19 variants through pre-existing antibodies from vaccination or previous infection is evident. Reports from around the world indicate that a considerable number of healthcare professionals/individuals experience re-infection despite being vaccinated. Moreover, several studies have highlighted cases of symptomatic SARS-CoV-2 re-infection, specifically among individuals who have been vaccinated. Understanding the factors that contribute to these re-infections is crucial for implementing effective public health measures and enhancing vaccination strategies.

Method

A comprehensive search was conducted between January 1, 2021, and February 14, 2024, using various reputable sources such as PubMed, Google scholar, Medline, EMBASE, CINAHL, and others. The search aimed to retrieve relevant research on topics related to "world nations" and phrases like "COVID-19 vaccination breakthrough infection," "SARS re-infection after COVID-19 vaccination," "COVID-19 vaccine complication," "post COVID-19 vaccination symptoms," and specific nation names. The data obtained from the databases underwent extraction and quality assessment using the Newcastle-Ottawa Scale (NOS) and the Preferred Reporting Items for Systematic Review and Meta-Analyses. Data analysis was performed using STATA17MP software, and measures such as the I2 test statistic and Egger's test were used to assess heterogeneity and publication bias. The findings were presented using forest plots, displaying the odds ratio (OR) and 95 % confidence interval (CI).

Result

This review and meta-analysis comprised a total of 15 articles, or a total sample size of 342,598. The pooled prevalence of SARS-CoV-2 after vaccination of COVID-19 was 9 % (95CI 7%-11 %) of population globally. This implied that reduced the overall attack rate of COVID-19 by 91 % after vaccination. The highest pooled estimated of SARS-CoV-2 infection after COVID -19 Vaccinations was seen among developing nations, 20 % (95 % CI: 5%-36 %).The pooled odds ratio showed that a significant association was found between SARS-CoV-2 infection after COVID-19 vaccination and older age (OR = 2.04; 95%CI: 1.10-2.98) and comorbidity (OR = 3.25; 95%CI: 1.04-5.47).

Conclusion

It is important for policymakers to prioritize continuous monitoring and surveillance of SARS-CoV-2 infection rates among vaccinated individuals globally, as there is a significant estimate of the combined prevalence of post-COVID-19 vaccine SARS-CoV-2 infections.

Attitudes and Practices Related to COVID-19 Vaccination with the Second Booster Dose among Members of Athens Medical Association: Results from a Cross-Sectional Study

BACKGROUND

There are limited data on the attitudes and acceptance of the second booster (fourth dose) of the COVID-19 vaccination among physicians.

METHODS

A cross-sectional, questionnaire-based, online study was conducted among members of the Athens Medical Association (A.M.A.) who were invited to participate anonymously over the period from January to March 2023.

RESULTS

From the 1224 members who participated in the survey, 53.9% did not receive the fourth dose of the COVID-19 vaccine. The main reasons for no vaccination were the lack of obligation to receive the fourth dose, the history of three doses of the COVID-19 vaccine and the lack of sufficient information about the effectiveness of the fourth dose. Over half of the three-dose-vaccinated participants were willing to receive the fourth dose in the near future. Interestingly, the vaccination coverage among participants who had been informed about the fourth dose through scientific sources was low.

CONCLUSIONS

The low vaccination coverage with the fourth dose reported in this study can lead to broad and serious consequences, such as increase in COVID-19 infections, reduction of available healthcare staff and increased caseloads of COVID-19 in hospitals. Furthermore, hesitant physicians will adversely influence the vaccination uptake among the general population due to their key role in informing and recommending the vaccine. The healthcare system administration should acknowledge and address physician's concerns through effective communication and better support.

Severity and Outcome of Post-Vaccine COVID-19 among Healthcare Workers in a University Hospital in India

Healthcare workers (HCWs) are at high risk of COVID-19 infection despite vaccination. Limited data exist on COVID-19 cases among vaccinated HCWs. This study aimed to describe the clinical characteristics and outcomes of RT PCR-confirmed COVID-19 cases in vaccinated HCWs, at a COVID clinic in a medical college hospital. This single-center, prospective cohort study included HCWs who received at least one dose of the COVID-19 vaccine and tested positive for COVID-19 within 6 months. Data on demographics, symptoms, work category, COVID-19 vaccination interval, and infection severity were collected. Of 2381 vaccinated HCWs, 105 tested positive and were categorized as mild, moderate, or severe cases. Among vaccinated HCWs, 4.41% had post-vaccine COVID-19 infections. All 105 cases received the first dose, and 79 received the second dose. Of the cases, 47.6% were partially vaccinated, and 53.3% were breakthrough cases. The mean age was 30.90±8.69 years, with 63.8% male and 36.2% female cases. Most cases (85.7%) acquired infection in the hospital, and 47.6% had direct contact with COVID-19 patients. Common symptoms included fatigue (85.7%), fever (82.9%), and cough (64.8%). Among cases, 93.3% were mild, 5.7% were moderate, and 0.9% were severe. Hospital admission and supplemental oxygen therapy were required for moderate and severe cases. No mortality was reported. Certain variables were associated with age, preventive measures, workplace type, symptoms, and comorbidities. Breakthrough infections can occur among fully vaccinated HCWs but with reduced severity and mortality. Monitoring and infection control measures remain crucial even in vaccinated individuals. This study provides insights into clinical presentations, oxygen therapy requirements, and outcomes of post-vaccine COVID-19 cases among HCWs. The data will inform strategies for booster doses to prevent COVID-19.

Effectiveness of full (booster) COVID-19 vaccination against severe outcomes and work absenteeism in hospitalized patients with COVID-19 during the Delta and Omicron waves in Greece

AIM

We estimated vaccine effectiveness (VE) of full (booster) vaccination against severe outcomes in hospitalized COVID-19 patients during the Delta and Omicron waves.

METHODS

The study extended from November 15, 2021 to April 17, 2022. Full vaccination was defined as a primary vaccination plus a booster ≥ 6 months later.

RESULTS

We studied 1138 patients (mean age: 66.6 years), of whom 826 (72.6 %) had > 1 comorbidity. Of the 1138 patients, 75 (6.6 %) were admitted to intensive care unit (ICU), 64 (5.6 %) received mechanical ventilation, and 172 (15.1 %) died. There were 386 (33.9 %) fully vaccinated, 172 (15.1 %) partially vaccinated, and 580 (51 %) unvaccinated patients. Unvaccinated patients were absent from work for longer periods compared to partially or fully vaccinated patients (mean absence of 20.1 days versus 12.3 and 17.3 days, respectively; p-value = 0.03). Compared to unvaccinated patients, fully vaccinated patients were less likely to be admitted to ICU [adjusted relative risk (ARR: 0.49; 95 % CI: 0.29-0.84)], mechanically ventilated (ARR: 0.43; 95 % CI: 0.23-0.80), and die (ARR: 0.57; 95 % CI: 0.42-0.78), while they were hospitalized for significantly shorter periods (ARR: 0.79; 95 % CI: 0.70-0.89). The adjusted full VE was 48.8 % (95 % CI: 42.7 %-54.9 %) against ICU admission, 55.4 % (95 % CI: 52.0 %-56.2 %) against mechanical ventilation, and 22.6 % (95 % CI: 7.4 %-34.8 %) against death. For patients with ≥ 3 comorbidities, VE was 56.2 % (95 % CI: 43.9 %-67.1 %) against ICU admission, 60.2 % (95 % CI: 53.7 %-65.4 %) against mechanical ventilation, and 43.9 % (95 % CI: 19.9 %-59.7 %) against death.

CONCLUSIONS

Full (booster) COVID-19 vaccination conferred protection against severe outcomes, prolonged hospitalization, and prolonged work absenteeism.

Timing of last COVID-19 vaccine dose and SARS-CoV-2 breakthrough infections in fully (boosted) vaccinated healthcare personnel

AIM

To estimate the incidence, timing and severity of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) breakthrough infections in fully vaccinated healthcare personnel (HCP).

METHODS

In total, 6496 fully vaccinated HCP were analysed prospectively from 15^th November 2021 to 17^th April 2022. Full coronavirus disease 2019 (COVID-19) vaccination was defined as a complete primary vaccination series followed by a booster dose at least 6 months later.

RESULTS

Overall, 1845 SARS-CoV-2 breakthrough infections occurred (28.4 episodes per 100 HCP), of which 1493 (80.9%) were COVID-19 cases and 352 (19.1%) were asymptomatic infections. Of the 1493 HCP with COVID-19, four were hospitalized for 3-6 days (hospitalization rate among HCP with COVID-19: 0.3%). No intubations or deaths occurred. SARS-CoV-2 breakthrough infections occurred at a mean of 16.2 weeks after the last vaccine dose. Multi-variable regression analyses showed that among the 1845 HCP with a breakthrough infection, the administration of a COVID-19 vaccine dose ≥16.2 weeks before the infection was associated with increased likelihood of developing COVID-19 rather than asymptomatic SARS-CoV-2 infection [odds ratio (OR) 1.58, 95% confidence interval (CI) 1.01-2.46; P=0.045] compared with administering a vaccine dose later. The likelihood of developing COVID-19 compared with asymptomatic infection increased by 7% weekly after the last COVID-19 vaccine dose (OR 1.07, 95% CI 1.03-1.11; P=0.001).

CONCLUSION

SARS-CoV-2 breakthrough infections are common among fully (boosted) vaccinated HCP. However, full COVID-19 vaccination offered considerable protection against hospitalization. These findings may contribute to defining the optimal timing for booster vaccinations. More efficient COVID-19 vaccines that will also confer protection against SARS-CoV-2 infection are needed urgently.

Association between COVID-19 vaccination status, time elapsed since the last vaccine dose, morbidity, and absenteeism among healthcare personnel: A prospective, multicenter study

AIM

We assessed the impact of COVID-19 vaccination status and time elapsed since the last vaccine dose on morbidity and absenteeism among healthcare personnel (HCP) in the context of a mandatory vaccination policy.

METHODS

We followed 7592 HCP from November 15, 2021 through April 17, 2022. Full COVID-19 vaccination was defined as a primary vaccination series plus a booster dose at least six months later.

RESULTS

There were 6496 (85.6 %) fully vaccinated, 953 (12.5 %) not fully vaccinated, and 143 (1.9 %) unvaccinated HCP. A total of 2182 absenteeism episodes occurred. Of 2088 absenteeism episodes among vaccinated HCP with known vaccination status, 1971 (94.4 %) concerned fully vaccinated and 117 (5.6 %) not fully vaccinated. Fully vaccinated HCP had 1.6 fewer days of absence compared to those not fully vaccinated (8.1 versus 9.7; p-value < 0.001). Multivariable regression analyses showed that full vaccination was associated with shorter absenteeism compared to not full vaccination (OR: 0.56; 95 % CI: 0.36-0.87; p-value = 0.01). Compared to a history of ≤ 17.1 weeks since the last dose, a history of > 17.1 weeks since the last dose was associated with longer absenteeism (OR: 1.22, 95 % CI:1.02-1.46; p-value = 0.026) and increased risk for febrile episode (OR: 1.33; 95 % CI: 1.09-1.63; p-value = 0.004), influenza-like illness (OR: 1.53, 95 % CI: 1.02-2.30; p-value = 0.038), and COVID-19 (OR: 1.72; 95 % CI: 1.24-2.39; p-value = 0.001).

CONCLUSIONS

The COVID-19 pandemic continues to impose a considerable impact on HCP. The administration of a vaccine dose in less than four months before significantly protected against COVID-19 and absenteeism duration, irrespective of COVID-19 vaccination status. Defining the optimal timing of boosters is imperative.

Did Italy Really Need Compulsory Vaccination against COVID-19 for Healthcare Workers? Results of a Survey in a Centre for Maternal and Child Health

Since its early spread, the COVID-19 pandemic has become a health threat globally. Due to their crucial role in the pandemic, Italy declared compulsory vaccination for healthcare workers. Vaccine hesitancy was observed among the healthcare workers and an ethical debate arose about Italian legal statement D.L. n. 44/2021. In this article, we present the results of a survey performed in an Italian center for maternal and infant care and assess the attitudes towards the COVID-19 pandemic and the mandatory COVID-19 vaccination of healthcare workers. Since March 2022, 91.5% of healthcare workers have been vaccinated with an additional dose. Only 2.3% of the respondents refused to take vaccination: the reasons behind this refusal were distrust, doubts over safety, and lack of information. Despite the high rate of response to vaccination, 17.7% of HCWs did not agree with its mandatory nature. In addition, 5.4% stated that they agreed to be vaccinated exclusively because of the sanctions provided for by the legislation. In conclusion, adequate vaccination coverage has been achieved in the hospital under consideration. However, it is still very important to continue to persuade HCWs of vaccine efficacy and safety, considering their social role.