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.

Pneumonia associated with SARS-COV2 infection in vaccinated patients

Objective: To describe the elapsed time between vaccination against SARS-COV2 and development of COVID19 pneumonia. To analyse the relation between COVID19 pneumonia and the time between doses as well as with patient profile. Material and/or methods: Cross-sectional descriptive study of patients diagnosed with COVID19 pneumonia and correctly vaccinated who have been notified to SEFV-h. The search for cases was carried out using the FEDRA 3 application between January and September 2021. Results: 99 cases of pneumonia in correctly vaccinated patients were identified;of these, 75 were vaccinated with Comirnaty, 12 with Janssen, 9 with Vaxzevria and 3 with Spikevax. Fifty-seven percent of pneumonias occurred 60 to 129 days after vaccination with a maximum ranging from 90 to 99 days (median 96). For analysis of the time between doses, the 87 cases that required two doses to complete vaccination schedule were considered. Nine of them had more than 2 months between doses, while 78 had less than 1 month (in 54% of the 87 cases 21 days had passed). There was no apparent association with the frequency of developing pneumonia. Thirty-seven percent were women and 60% men. To assess age, the cases were distributed by decade. Thus, the age group >79 had the highest number of cases (52), while the groups 60-69 and 70-79 comprised 18 cases each. The least cases were in the remaining groups: 8 (50-59), 2 (40-49) and 1 (30-39). There was none in the lower age groups. Conclusions: The data indicate that most cases of vaccine failure with severe disease occur 3 months after vaccination. Compared to pre-vaccination data collected from other sources, a decrease in severe cases was observed, with unchanged patient profile in terms of age and sex.

Effect of SARs-Cov-2 mRNA Vaccination in Healthcare Workers with Household COVID Exposure

Background. Healthcare workers have experienced a significant burden of COVID-19 disease. COVID mRNA vaccines have shown great efficacy in prevention of severe disease and hospitalization due to COVID infection, but limited data is available about acquisition of infection and asymptomatic viral shedding. Methods. Fully vaccinated healthcare workers at a tertiary-care academic medical center in Omaha Nebraska who reported a household exposure to COVID-19 infection are eligible for a screening program in which they are serially screened with PCR but allowed to work if negative on initial test and asymptomatic. Serial screening by NP swab was completed every 5-7 days, and workers became excluded from work if testing was positive or became symptomatic. Results. Of the 94 employees who were fully vaccinated at the time of the household exposure to COVID-19 infection, 78 completed serial testing and were negative. Sixteen were positive on initial or subsequent screening. Vaccine failure rate of 17.0% (16/94). Conclusion. High risk household exposures to COVID-19 infection remains a significant potential source of infections in healthcare workers even after workers are fully vaccinated with COVID mRNA vaccines especially those with contact to positive domestic partners.

Emergence of SARS-CoV-2 Omicron (B.1.1.529) variant, salient features, high global health concerns and strategies to counter it amid ongoing COVID-19 pandemic.

Since the appearance in the late of December 2019, SARS-CoV-2 is rapidly evolving and mutating continuously, giving rise to various variants with variable degrees of infectivity and lethality. The virus that initially appeared in China later mutated several times, wreaking havoc and claiming many lives worldwide amid the ongoing COVID-19 pandemic. After Alpha, Beta, Gamma, and Delta variants, the most recently emerged variant of concern (VOC) is the Omicron (B.1.1.529) that has evolved due to the accumulation of high numbers of mutations especially in the spike protein, raising concerns for its ability to evade from pre-existing immunity acquired through vaccination or natural infection as well as overpowering antibodies-based therapies. Several theories are on the surface to explain how the Omicron has gathered such a high number of mutations within less time. Few of them are higher mutation rates within a subgroup of population and then its introduction to a larger population, long term persistence and evolution of the virus in immune-compromised patients, and epizootic infection in animals from humans, where under different immune pressures the virus mutated and then got reintroduced to humans. Multifaceted approach including rapid diagnosis, genome analysis of emerging variants, ramping up of vaccination drives and receiving booster doses, efficacy testing of vaccines and immunotherapies against newly emerged variants, updating the available vaccines, designing of multivalent vaccines able to generate hybrid immunity, up-gradation of medical facilities and strict implementation of adequate prevention and control measures need to be given high priority to handle the on-going SARS-CoV-2 pandemic successfully.

Measles in Vaccinated People: Epidemiology and Challenges in Surveillance and Diagnosis in the Post-Elimination Phase. Spain, 2014-2020.

The MMR vaccination program was introduced in Spain in 1981. Consistently high vaccination coverage has led to Spain being declared free of endemic measles transmission since 2014. A few imported and import-related cases were reported during the post-elimination phase (2014 to 2020), with very low incidence: three cases per million of inhabitants a year, 70% in adults. In the post-elimination phase an increasing proportion of measles appeared in two-dose vaccinated individuals (up to 14%), posing a challenge to surveillance and laboratory investigations. Severity and clinical presentation were milder among the vaccinated. The IgM response varied and the viral load decreased, making the virus more difficult to detect. A valid set of samples (serum, urine and throat swab) is strongly recommended for accurate case classification. One third of measles in fully vaccinated people was contracted in healthcare settings, mainly in doctors and nurses, consistent with the important role of high intensity exposure in measles breakthrough cases. Surveillance protocols and laboratory algorithms should be adapted in advanced elimination settings. Reinforcing the immunity of people working in high exposure environments, such as healthcare settings, and implementing additional infection control measures, such as masking and social distancing, are becoming crucial for the global aim of measles eradication.

Cross-reactive Antibody Response to mRNA SARS-CoV-2 Vaccine After Recent COVID-19-Specific Monoclonal Antibody Therapy.

The efficacy of coronavirus disease 2019 (COVID-19) vaccines administered after COVID-19-specific monoclonal antibody is unknown, and "antibody interference" might hinder immune responses leading to vaccine failure. In an institutional review board-approved prospective study, we found that an individual who received mRNA COVID-19 vaccination <40 days after COVID-19-specific monoclonal antibody therapy for symptomatic COVID-19 had similar postvaccine antibody responses to SARS-CoV-2 receptor binding domain (RBD) for 4 important SARS-CoV-2 variants (B.1, B.1.1.7, B.1.351, and P.1) as other participants who were also vaccinated following COVID-19. Vaccination against COVID-19 shortly after COVID-19-specific monoclonal antibody can boost and expand antibody protection, questioning the need to delay vaccination in this setting. TRIAL REGISTRATION: The St. Jude Tracking of Viral and Host Factors Associated with COVID-19 study; NCT04362995; https://clinicaltrials.gov/ct2/show/NCT04362995.