Risk factors for severe Covid-19 breakthrough infections: an observational longitudinal study.

BACKGROUND: The drive to vaccinate large populations is nowadays the main instrument for combating the pandemic and preventing serious disease and death. However, breakthrough infection (post-vaccination infection) still happens after vaccination among fully vaccinated people. We aimed to assess the severity outcomes and to determine its associated factors among vaccinated COVID-19 cases in the governorate of Sousse, Tunisia. METHODS: We carried out a five-month observational longitudinal study including all the population of Sousse. Confirmed infections of SARS-CoV-2 and the vaccination status are recorded in the daily COVID- 19 database of the Regional Office of the Tunisian Ministry of Health. We included all post-vaccination COVID-19 cases for the analysis of the COVID-19 serious outcomes. Data were collected via 15-min telephonic call interviews conducted by trained interviewers. Descriptive analysis with calculating incidence rates of confirmed COVID-19 cases per 100,000 inhabitants was conducted. In binary logistic regression, adjusted odds ratios along with 95% intervals confidence were performed to determine factors related to severe or critical COVID-19. RESULTS: As of 31 July 2021, 107,545 persons over 19 years old have received at least one dose of COVID-19 vaccination. Among the vaccinated population, we traced and included 765 breakthrough infection cases, and the incidence rate was 711.3 per week. The majority were female (sex-ratio = 0.8), and the average age of the overall cases was 55.7 years. The prevalence of severe or critical cases in vaccinated COVID-19 patients occurs in 10.8% of cases. Patients with a medical history of cardiovascular diseases had more than two times increased odds to have a severe or critical disease. We also found the highest self-estimation of adherence to preventive measures was inversely correlated to serious cases and having an incomplete vaccination schema was strongly associated with complications. CONCLUSIONS: We tried to provide evidence about the breakthrough infections to improve measures of prevention and control of COVID-19. Boosting immunity for vulnerable patients added to maintaining and promoting preventive measures are not only essential to prevent severe cases of breakthrough infections of COVID-19, but also other influenza-like diseases.

Neutralizing Antibody Response, Safety, and Efficacy of mRNA COVID-19 Vaccines in Pediatric Patients with Inflammatory Bowel Disease: A Prospective Multicenter Case-Control Study.

The vaccination of immunocompromised children against coronavirus disease 2019 is an important public health issue. We evaluated the serological response, safety, and efficacy of the BNT162b2 vaccine in children with and without inflammatory bowel disease (IBD). A prospective, multicenter, case-control study was conducted in a pediatric population, including patients with IBD, aged 12-18 years. Clinical characteristics, safety profile, and serum samples for surrogate virus-neutralizing antibody testing pre- and post-BNT162b2 vaccination were assessed. The breakthrough infection rate during the Omicron outbreak was calculated to evaluate efficacy. Fifteen controls and twenty-three patients with IBD were enrolled. After two vaccine doses, the median level of percentage inhibition was highly increased, without significant differences between the groups (control 96.9 and IBD 96.3). However, it was significantly reduced in IBD patients receiving combination therapy (anti-tumor necrosis factor-α + immunomodulators) relative to those in other therapies and controls. Serious adverse events were not observed. The breakthrough infection rate was 42.1%, without statistical differences between the groups. Immunization with BNT162b2 in patients with IBD was comparable with that in healthy adolescents in terms of immunogenicity and safety. Nevertheless, the efficacy of BNT162b2 in preventing infection caused by the Omicron variant in the pediatric population was insufficient.

Covid-19 vaccination in autoimmune rheumatic diseases: A multi-center survey from southern India.

AIM: This survey was conducted to evaluate COVID-19 vaccination status in patients with autoimmune rheumatic diseases (AIRDs). Our objectives were to study vaccine hesitancy, adverse effects, breakthrough infections and flare of underlying disease in this population subgroup. METHODS: This was a multi-center, cross-sectional, interview-based survey done at 6 tertiary care centers across Tamil Nadu, in the southern part of India from September 15, 2021 to October 14, 2021. The survey questionnaire was filled up by AIRD patients attending their clinics. The survey questionnaire comprised a set of 14 questions, distributed between patient characteristics, vaccines taken, their characteristics and COVID-19 infection. RESULTS: There were 2092 participants, with a mean age of 47.5 ± 13.17 years. Among them, 1293 (61.81%) were vaccinated, of which 837 (64.73%) were fully vaccinated. Two-thirds of our subjects were vaccinated with ChAdOx1 nCov-19 (COVISHIELD) (77.64%) and 21.57% with BBV 152 (COVAXIN). Age, gender, education and comorbidities had no association with vaccine hesitancy. The commonest (421; 52.69%) reason for vaccine hesitancy was fear of side effects. The incidence (n = 72) of breakthrough infections was similar in both the vaccine groups, of which 58 (80.55%) were partially vaccinated and 14 (19.44%) were fully vaccinated. Thirty-two patients had a flare of pre-existing rheumatic disease. CONCLUSION: ChAdOx1 nCov-19 and BBV 152 were found to be safe in patients with rheumatic diseases. Fear of side effects was the major cause of vaccine hesitancy. All adverse effects were minor and self-limiting. Breakthrough infections and disease flares occurred only in a small subset of our cohort.

Vaccine breakthrough infections in a highly-vaccinated Australian population during a SARS-CoV-2 Delta outbreak.

Abstract: Over 80% of residents in the Australian Capital Territory were fully vaccinated within 10 weeks of a SARS-CoV-2 Delta variant outbreak. Of the outbreak's 1,545 cases, 10% were breakthrough infections. The incidence of infections among fully- and partially-vaccinated people was 98.5% and 90% lower, respectively, than for unvaccinated people.

Clinical characteristics and outcome of hospitalized elderly patients with COVID- 19 after vaccine failure.

We described clinical characteristics and outcome of 160 patients over 65 years (01 September to 31 August 2021) who had a first positive SARS-CoV-2 PCR- test more than 14 days after full vaccination and were hospitalized with COVID-19. Median age of included patients was 84 years, 61.2% were over 80 years; 50.6% were male and most (82.5%) has at least one comorbidity. Up to 84% received specific treatment against COVID-19, including 76.9% low-flow oxygen therapy. We found that overall mortality was 25.6% and 30.6% in those older than 80 years. A higher mortality was significantly associated with older age and treatment with tocilizumab. Our data showed that although COVID-19 vaccines continue protecting elderly patients against hospitalization and death and might improve the prognosis after hospitalization in patients with breakthrough infections, mortality in this population -especially in those older than 80 years- remains very high.

Immunogenicity and risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection after Coronavirus Disease 2019 (COVID-19) vaccination in patients with cancer: a systematic review and meta-analysis.

BACKGROUND: Patients with cancer are considered a priority group for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) vaccination given their high risk of contracting severe Coronavirus Disease 2019 (COVID-19). However, limited data exist regarding the efficacy of immunisation in this population. In this study, we assess the immunologic response after COVID-19 vaccination of cancer versus non-cancer population. METHODS: PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science databases were searched from 01st March 2020 through 12th August 12 2021. Primary end-points were anti-SARS-CoV-2 spike protein (S) immunoglobulin G (IgG) seroconversion rates, T-cell response, and documented SARS-CoV-2 infection after COVID-19 immunisation. Data were extracted following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Overall effects were pooled using random-effects models. RESULTS: This systematic review and meta-analysis included 35 original studies. Overall, 51% (95% confidence interval [CI], 41-62) and 73% (95% CI, 64-81) of patients with cancer developed anti-S IgG above the threshold level after partial and complete immunisation, respectively. Patients with haematologic malignancies had a significantly lower seroconversion rate than those with solid tumours after complete immunisation (65% vs 94%; P < 0.0001). Compared with non-cancer controls, oncological patients were less likely to attain seroconversion after incomplete (risk ratio [RR] 0.45 [95% CI 0.35-0.58]) and complete (RR 0.69 [95% CI 0.56-0.84]) COVID-19 immunisation schemes. Patients with cancer had a higher likelihood of having a documented SARS-CoV-2 infection after partial (RR 3.21; 95% CI 0.35-29.04) and complete (RR 2.04; 95% CI 0.38-11.10) immunisation. CONCLUSIONS: Patients with cancer have an impaired immune response to COVID-19 vaccination compared with controls. Strategies that endorse the completion of vaccination schemes are warranted. Future studies should aim to evaluate different approaches that enhance oncological patients' immune response.

A fatal case of COVID-19 breakthrough infection due to the delta variant.

COVID-19 infections that occur at least 2 weeks after complete vaccination are known as breakthrough infections. Herein, we report a clinical case resembling breakthrough infection that was correlated with a higher score of COVID-19 pneumonia on chest computed tomography (CT) in a patient who resulted positive for the delta variant and who died during the hospitalization.