Vaccination Status and Number of Vaccine Doses Are Independently Associated with the PaO2/FiO2 Ratio on Admission in Hospitalized COVID-19 Patients

Development and evaluation of a Lateral flow immunoassay (LFIA) prototype for the detection of IgG anti-SARS-CoV-2 antibodies

Lateral flow immunoassays (LFIA) for antibody detection represent cost-effective and user-friendly tools for serology assessment. This study evaluated a new LFIA prototype developed with a recombinant chimeric antigen from the spike/S and nucleocapsid/N proteins to detect anti-SARS-CoV-2 IgG antibodies. The evaluation of LFIA sensitivity and specificity used 811 serum samples from 349 hospitalized, SARS-CoV-2 RT-qPCR positive COVID-19 patients, collected at different time points and 193 serum samples from healthy controls. The agreement between ELISA results with the S/N chimeric antigen and LFIA results was calculated. The LFIA prototype for SARS-CoV-2 using the chimeric S/N protein demonstrated 85 % sensitivity on the first week post symptoms onset, reaching 94 % in samples collected at the fourth week of disease. The agreement between LFIA and ELISA with the same antigen was 92.7 %, 0.827 kappa Cohen value (95 % CI [0.765-0.889]). Further improvements are needed to standardize the prototype for whole blood use. The inclusion of the novel chimeric S + N antigen in the COVID-19 IgG antibody LFIA demonstrated optimal agreement with results from a comparable ELISA, highlighting the prototype's potential for accurate large-scale serologic assessments in the field in a rapid and user-friendly format.

Differences in complete blood count parameters in patients with COVID-19 diagnosis based on vaccination status (literature review)

Relevance. Due to the large-scale vaccination campaigns against the SARS-CoV-2 coronavirus taking place worldwide, the question arises as to how vaccination may affect complete blood count (CBC) parameters in COVID-19 cases. Research objective: assess differences in complete blood count parameters in COVID-19 patients based on their vaccination status. Materials and methods. A review of publications was conducted describing and presenting the complete blood count parameters in patients with verified COVID-19, by stratifying them into vaccinated and unvaccinated individuals against the SARS-CoV-2 virus-caused disease. Subsequently, a meta-analysis of the results for each CBC parameter was carried out by describing identified differences among patients with mild and moderate COVID-19, lacking comorbidities affecting CBC indicators. Results. The analysis conducted allowed to determine that the complete blood count parameters do not exceed the reference range in most cases in both groups, excepting those of individuals with a severe disease course. The exception is the erythrocyte sedimentation rate (ESR) (42 [20.5–63.5] (∑n = 107, Me [Q1–Q3])) mm/h in unvaccinated individuals. Also, a slightly lower absolute lymphocyte count is observed in vaccinated individuals (0.95 [0.58–1.62] × 109/L (∑n = 441, Me [Q1–Q3])). There is a twofold greater range of leukocyte quartile values in vaccinated individuals compared to unvaccinated individuals: 7.07 [4.07–12.31] × 109/L (∑n = 555, Me [Q1–Q3]) vs 5.68 [4.02–8.34] × 109/L (∑n = 2202, Me [Q1–Q3]). A similar pattern is observed for monocytes. Conclusion. Conducting a meta-analysis of laboratory parameters in COVID-19 cases among vaccinated and unvaccinated individuals allows for determining the effectiveness of vaccination as well as identify the major trends in dynamic changes for essential blood parameters among unvaccinated and vaccinated individuals in general or with certain immunobiological preparations.

Comparison of Clinical Features, Complete Blood Count Parameters, and Outcomes between Two Distinct Waves of COVID-19: A Monocentric Report from Italy

BACKGROUND

Since the beginning of the SARS-CoV-2 pandemic, the ability to predict the trajectory of the disease has represented a major challenge for clinicians. There is recent evidence that complete blood cell count (CBC)-derived inflammation indexes have predictive value in COVID-19. We aimed to describe any changes in the clinical features, CBC-derived ratios, and outcomes of patients admitted to our hospital across two temporally distinct waves.

METHODS

We retrospectively assessed and compared the clinical characteristics and blood cell count values of patients hospitalized during the second and fourth waves of COVID-19, and explored any outcome differences in terms of the level of respiratory support required and transfer to intensive care.

RESULTS

We observed that fourth-wave patients were older, less male-predominant, and carried more comorbidities compared to the second-wave patients but, nevertheless, experienced more favorable outcomes. A strong internal correlation was documented for both waves between outcomes and CBC-derived ratios, with the fourth-wave cases displaying lower admission values of the neutrophil-to-lymphocyte ratio (NLR), derived NLR (dNLR), platelet-to-lymphocyte ratio (PLR), and systemic inflammation index (SII). No significant differences were found for lymphocyte-to-monocyte ratio (LMR), systemic inflammation response index (SIRI), and aggregate index of systemic inflammation (AISI).

CONCLUSIONS

We observed that both admission values of CBC-derived indexes and adverse respiratory outcomes decreased from the second to the fourth wave of COVID-19. These data represent a contribution to the existing knowledge on the role of CBC-derived indexes as a potential tool to help clinicians to quickly differentiate in-hospital patients at increased risk of serious illness and death.