Clinical Characteristics and Outcomes of Critically Ill Patients with 1, 2 and 3 doses of Vaccination against COVID-19 in Australia

Influence of vaccination on critical COVID-19 patients with acute respiratory failure: a retrospective cohort study

BACKGROUND

Despite vaccines' effectiveness in reducing COVID-19 infection rates and disease severity, their impact on critical patients presenting with acute respiratory failure is elusive. The aim of this study was to further investigate the influence of vaccination on mortality rates among severely ill COVID-19 patients experiencing acute respiratory failure.

METHODS

This retrospective cohort study was carried out at a tertiary medical center in Taiwan. From April to September 2022, patients who tested positive for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) through reverse transcription polymerase chain reaction (RT-PCR) and subsequently experienced acute respiratory failure were included in the study. Baseline characteristics, including vaccination history, along with information regarding critical illness and clinical outcomes, were gathered and compared between patients who received the vaccine and those who did not.

RESULTS

A total of 215 patients with COVID-19 exhibiting acute respiratory failure, as confirmed via RT‒PCR, were included in the analysis. Of this cohort, sixty-six (30.7%) patients died within 28 days. Neither administration of the vaccine nor achievement of primary series vaccination status had a significantly different effect on 28 day mortality, number of viral shedding events, acute respiratory distress syndrome (ARDS) incidence or other clinical outcomes. Patients who received the booster vaccine and completed the primary series showed a tendency of increased 28 days of ventilator-free status, though this difference was not statistically significant (p = 0.815).

CONCLUSIONS

Vaccination status did not significantly influence mortality rates, the occurrence of ARDS, or the viral shedding duration in COVID-19 patients with acute respiratory failure.

Vaccination status and outcomes in critical COVID-19 patients

OBJECTIVE

To analyze the clinical characteristics and outcomes of patients with COVID-19-related acute respiratory failure on the basis of their vaccination status at the time of ICU admission.

METHODS

We conducted a retrospective observational study using a prospective database of patients admitted to the ICU of a university hospital in the city of Murcia, in Spain, between January 1, 2021 and September 1, 2022. Clinical, analytical, and sociodemographic data were collected and analyzed on the basis of patient vaccination status. We adjusted for confounding variables using propensity score matching and calculated adjusted ORs and 95% CIs.

RESULTS

A total of 276 patients were included in the study. Of those, 8.3% were fully vaccinated, 12% were partially vaccinated, and 79.7% were unvaccinated. Although fully vaccinated patients had more comorbidities, partially vaccinated patients had higher disease severity. The proportion of patients with severe acute respiratory failure was higher in the unvaccinated group, followed by the partially vaccinated group. No significant differences were found among the different groups regarding complications, duration of ventilatory support, or length of ICU/hospital stay. In the sample selected by propensity score matching, the number of patients with severe complications and the in-hospital mortality rate were higher in unvaccinated patients, but the differences were not significant.

CONCLUSIONS

This study failed to show a significant improvement in outcomes in critically ill COVID-19 patients vaccinated against SARS-CoV-2. However, the CIs were wide and the mortality point estimates favored patients who received at least one dose of COVID-19 vaccine.

Estimation of the effect of vaccination in critically ill COVID-19 patients, analysis using propensity score matching

BACKGROUND

Vaccination helped in reducing mortality and disease severity due to COVID-19. Some patients can develop breakthrough infections. The effect of vaccination in critically ill patients admitted with breakthrough infections is not well studied. We designed a study to estimate the effect of vaccination on ICU mortality in critically ill COVID-19 patients by using propensity score matching.

METHODS

We included patients from 15th June 2020 to 31st December 2021. Inclusion criteria were unvaccinated and vaccinated COVID-19 patients requiring intensive care unit (ICU) admission. The institutional ethics committee approval was obtained (institutional ethics committee, IEC 08/2023, Clinical trial registry, India CTRI/2023/01/049142). The primary outcome was ICU mortality. The secondary outcomes were the length of ICU stay and duration of mechanical ventilation. We used multivariable logistic regression (MLR) and propensity score matching (PSM) for the statistical analysis.

RESULTS

Total of 667 patients (79.31%) were unvaccinated and 174 (20.68%) vaccinated. The mean age was 57.11 [standard deviation (SD) 15.13], and 70.27% were males. The ICU mortality was 56.60% [95% confidence interval (CI) 53.24-60%]. The results of MLR and PSM method showed that vaccinated patients were less likely to be associated with mortality [adjusted odds ratio (AOR), 95% CI using logistic regression: 0.52 (0.29, 0.94), and by propensity score matching: 0.83 (0.77, 0.91)].

CONCLUSION

The findings of this study support COVID-19 vaccination as an effective method for reducing case fatality not only in the general population but also in critically ill patients, and it has important public health implications.

The Impact of CoronaVac Vaccination on 28-day Mortality Rate of Critically Ill Patients with COVID-19 in Türkiye

Background

Vaccines against coronavirus disease-19 (COVID-19) have been effective in preventing symptomatic diseases, hospitalizations, and intensive care unit (ICU) admissions. However, data regarding the effectiveness of COVID-19 vaccines in reducing mortality among critically ill patients with COVID-19 remains unclear.

Aims

To determine the vaccination status and investigate the impact of the COVID-19 vaccine on the 28-day mortality in critically ill patients with COVID-19.

Study Design

Multicenter prospective observational clinical study.

Methods

This study was conducted in 60 hospitals with ICUs managing critically ill patients with COVID-19. Patients aged ≥ 18 years with confirmed COVID-19 who were admitted to the ICU were included. The present study had two phases. The first phase was designed as a one-day point prevalence study, and demographic and clinical findings were evaluated. In the second phase, the 28-day mortality was evaluated.

Results

As of August 11, 2021, 921 patients were enrolled in the study. The mean age of the patients was 65.42 ± 16.74 years, and 48.6% (n = 448) were female. Among the critically ill patients with COVID-19, 52.6% (n = 484) were unvaccinated, 7.7% (n = 71) were incompletely vaccinated, and 39.8% (n = 366) were fully vaccinated. A subgroup analysis of 817 patients who were unvaccinated (n = 484) or who had received two doses of the CoronaVac vaccine (n = 333) was performed. The 28-day mortality rate was 56.8% (n = 275) and 57.4% (n = 191) in the unvaccinated and two-dose CoronaVac groups, respectively. The 28-day mortality was associated with age, hypertension, the number of comorbidities, type of respiratory support, and APACHE II and sequential organ failure assessment scores (p < 0.05). The odds ratio for the 28-day mortality among those who had received two doses of CoronaVac was 0.591 (95% confidence interval: 0.413-0.848) (p = 0.004).

Conclusion

Vaccination with at least two doses of CoronaVac within six months significantly decreased mortality in vaccinated patients than in unvaccinated patients.

Vaccination status of COVID-19 patients followed up in the ICU in a country with heterologous vaccination policy: A multicenter national study in Turkey

OBJECTIVE

Vaccination against severe acute respiratory syndrome coronavirus-2 (SARS-2) prevents the development of serious diseases has been shown in many studies. However, the effect of vaccination on outcomes in COVID-19 patients requiring intensive care is not clear.

METHODS

This is a retrospective multicenter study conducted in 17 intensive care unit (ICU) in Turkey between January 1, 2021, and December 31, 2021. Patients aged 18 years and older who were diagnosed with COVID-19 and followed in ICU were included in the study. Patients who have never been vaccinated and patients who have been vaccinated with a single dose were considered unvaccinated. Logistic regression models were fit for the two outcomes (28-day mortality and in-hospital mortality).

RESULTS

A total of 2968 patients were included final analysis. The most of patients followed in the ICU during the study period were unvaccinated (58.5%). Vaccinated patients were older, had higher Charlson comorbidity index (CCI), and had higher APACHE-2 scores than unvaccinated patients. Risk for 28-day mortality and in-hospital mortality was similar in across the year both vaccinated and unvaccinated patients. However, risk for in-hospital mortality and 28-day mortality was higher in the unvaccinated patients in quarter 4 adjusted for gender and CCI (OR: 1.45, 95% CI: 1.06-1.99 and OR: 1.42, 95% CI: 1.03-1.96, respectively) compared to the vaccinated group.

CONCLUSION

Despite effective vaccination, fully vaccinated patients may be admitted to ICU because of disease severity. Unvaccinated patients were younger and had fewer comorbid conditions. Unvaccinated patients have an increased risk of 28-day mortality when adjusted for gender and CCI.

Severe SARS-Cov2 pneumonia in vaccinated patients: a multicenter cohort study

Vaccination reduces risk of infection, hospitalization, and death due to SARS-Cov2. Vaccinated patients may however experience severe SARS-Cov2 disease. The objective was to describe clinical features of vaccinated patients requiring intensive care unit (ICU) admission due to SARS-Cov2 infection and compare them to a published cohort of unvaccinated patients. We performed a multicenter cohort study of patients with severe SARS-Cov2 disease admitted to 15 ICUs in France between January and September 2021. 100 consecutive vaccinated patients (68 (68%) men, median age 64 [57-71]) were included. Immunosuppression was reported in 38 (38%) patients. Among available serologies at ICU admission, 64% exhibited an optimal antibody level. Median SOFA score at ICU admission was 4 [4-6.3] and median PaO2/FiO2 ratio was 84 [69-128] mmHg. A total of 79 (79%) and 18 (18%) patients received high flow nasal oxygen and non-invasive mechanical ventilation, respectively. Invasive mechanical ventilation (IMV) was initiated in 48 (48%) with a median duration of 11 [5-19] days. During a median ICU length-of-stay of 8 [4-20] days, 31 (31%) patients died. Age (OR per 5-years increment 1.38 CI95% [1.02-1.85], p = 0.035), and SOFA at ICU admission (OR 1.40 CI95% [1.14-1.72] per point, p = 0.002) were independently associated with mortality. When compared to a cohort of 1316 unvaccinated patients (72% men, median age 63 [53-71]), vaccinated patients exhibited less frequently diabetes (16 [16%] vs. 351 [27%], p = 0.029) but were more frequently immunosuppressed (38 [38%] vs. 109 (8.3%), p < 0.0001), had more frequently chronic kidney disease (24 [24%] vs. 89 (6.8%), p < 0.0001), chronic heart failure (16 [16%] vs. 58 [4.4%], p < 0.0001), and chronic liver disease (3 [3%] vs. 8 [0.6%], p = 0.037) compared to unvaccinated patients. Despite similar severity, vaccinated patients required less frequently IMV at ICU day 1 and during ICU stay (23 [23%] vs. 785 [59.7%], p < 0.0001, and 48 [48%] vs. 930 [70.7%], p < 0.0001, respectively). There was no difference concerning ICU mortality (31 [31%] vs. 379 [28.8%], p = 0.64). Severe SARS-Cov2 infection after vaccination occurs mainly in patients with immunosuppression, chronic kidney, heart or liver failure. Age and disease severity are independently associated with mortality.

Outcomes of Elderly Patients Hospitalized with the SARS-CoV-2 Omicron B.1.1.529 Variant: A Systematic Review

The Omicron (B.1.1.529) variant of the severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) had an increased rate of spreading among the general population. Although this virus mutation resulted in milder symptoms, those on the vulnerable side of the population are still in danger of developing severe symptoms. Thus, this systematic review focused on identifying the clinical outcomes of older age patients (>65) that are hospitalized with the SARS-CoV-2 Omicron variant. The research was conducted using four electronic databases (PubMed, Scopus, Web of Science, and ProQuest Central), with a search query in December 2022 that comprised the duration of the COVID-19 pandemic. The inclusion criteria comprised (1) a population of patients older than 65 years, (2) a history of hospitalization for SARS-CoV-2 infection, and (3) infection with Omicron B.1.1.529 variant. The initial search generated 295 articles, out of which six were included in the systematic review, and a total of 7398 patients. The main findings were that when looking at the elderly population, the mortality and hospitalization rates remained high. This is because older people are more vulnerable and have more comorbidities that interfere with the virus's progress. However, there is inconsistency in mortality rates, since the data reported by the included studies had different selection criteria based on the severity of the COVID-19 infection. Although no statistically significant differences were found between the unvaccinated and vaccinated groups, patients who got booster doses of vaccination had a lower likelihood of developing severe symptoms, serving as a protective factor for this population.

Multimorbidity and Frailty Are the Key Characteristics of Patients Hospitalized with COVID-19 Breakthrough Infection during Delta Variant Predominance in Italy: A Retrospective Study

The aims of this study were to describe the characteristics of patients hospitalized with delta SARS-CoV-2 breakthrough infection, and to identify factors associated with pneumonia on chest Computed Tomography (CT) and mortality. The clinical records of 229 patients (105 F), with a median age of 81 (interquartile range, IQR, 73−88) years old, hospitalized between June and December 2021 after completion of the primary vaccination cycle, were retrospectively analyzed, retrieving data on comorbidities, Clinical Frailty Scale (CFS), clinical presentation and outcomes. Multimorbidity (91.7% with ≥2 chronic illnesses) and frailty (61.6% with CFS ≥ 5) were highly prevalent. CFS (OR 0.678, 95% CI 0.573−0.803, p < 0.001) and hypertension were independently associated with interstitial pneumonia. Mortality was 25.1% and unrelated with age. PaO2/FiO2 on blood gas analysis performed upon admission (OR 0.986, 95% CI 0.977−0.996, p = 0.005), and CFS (OR 1.723, 95% CI 1.152−2.576, p = 0.008) were independently associated with mortality only in subjects < 85 years old. Conversely, serum PCT levels were associated with mortality in subjects ≥ 85 years old (OR 3.088, 95% CI 1.389−6.8628, p = 0.006). In conclusion, hospitalization for COVID-19 breakthrough infection mainly involved geriatric patients, with those aged ≥ 85 more characterized by decompensation of baseline comorbidities rather than typical COVID-19 respiratory symptoms.