Correlation between antibody response and neutralization capability induced by SARS-COV- 2 vaccine BNT162b2 in the CORIMUN study

Background: In the last two years the pandemic Coronavirus Disease 19 (Covid19), caused by the virus SARS-CoV- 2, described for the first time in Wuhan (China) at the end of 2019, has caused over 359 million cases of infections and 5 million deaths worldwide. To fight this emergency, the pursuit of science has focused on vaccines development against SARS-CoV- 2, including the vaccine BNT162b2. This vaccine contains mRNA translating for SARS-CoV- 2 spike protein wrapped in lipid nanoparticles and its use was approved at the end of 2020. It has been proved that both the BNT162b2 vaccine and the SARS-CoV- 2 infection result in the production of neutralizing antibodies but remains to be clarified the duration of these responses, also versus variants of concern. Method(s): The present study aimed to prospectively analyse and correlate the antibody response and the neutralization capability induced by vaccination with BNT162b2 in a cohort of Sardinian subjects, including a group previously Cov2 infected. Each participant was evaluated for serum SARS-CoV2 Ab IgG RDB, 7 (T1) and 30 (T2) days after the second inoculum of BNT162b2, with chemiluminescent immunoassays (CLIA) and microneutralization assay (MNA) determining the highest serum dilution protecting 90 % of the infected wells. Result(s): All the participants, with or without previous infection, developed a positive antibody response (IgG anti-RBD > 1 AU/ml) within 7 and 30 days from the second vaccine dose and a strong correlation was found between IgG antibody levels and neutralizing activity. A strong difference was observed between the antibody levels of the naive subjects and the ones previously infected, specifically the antibody levels were higher (both at T1 and T2) in the latter group. No significant antibody differences were found for gender and age groups. In addition, there were no significant differences in antibody titre between healthy and immune-mediated subjects. Conclusion(s): In conclusion, this study confirms observed differences in vaccine responses between infection-naive and subjects with history of natural infection, with the presence in the second group of a significantly higher neutralizing and anti-RBD antibody titer. It also demonstrates the strong correlation between anti-RBD antibody titre and neutralizing activity, without significant differences between healthy subjects and subjects with immuno-mediated disease in the short-term. Further follow-up is ongoing in this cohort.

Antibody response to heterologous prime-boost vaccination with ChAdOx1 nCoV-19 and BNT162b2 up to 28 weeks: A comparison between vaccination regimens

Background: The occurrence of side effects, such as thrombotic events, related to vaccination with ChAdOx1 nCoV-19, led in many countries to heterologous messenger RNA (mRNA) boosting. Method(s): We tested the antibody response to SARS-CoV- 2 spike protein 4 and 15 weeks after heterologous priming with the ChAdOx1 (ChAd) vector vaccine followed by boosting with BNT162b2(ChAd/ BNT) comparing data of homologous regimen (BNT/BNT, ChAd/ ChAd), subjects positive for SARS-CoV- 2 after the first dose of BNT162b2 (BNT1dose/CoV2) and convalescent COVID-19. We also evaluated again at 28 weeks after completion of the primary schedule any differences between residual antibody response resulting from a heterologous course and the one deriving from homologous regimen. Healthy subjects naive for SARS-CoV- 2 infection were assessed for serum IgG anti-S- RBD response 21 days after priming (T1), 4 (TFULL), 15 (T15W) and 28 (T28W) weeks after booster dose. Result(s): The median IgG anti-S- RBD levels at TFULLof Chad/BNT group were significantly higher than the BNT/BNT group and ChAd/ChAd. Those of BNT/BNT group were significantly higher than ChAd/ChAd. IgG anti-S- RBD of BNT1dose/CoV2 group were similar to BNT/BNT, ChAd/BNT and ChAd/Chad group. The levels among COVID-19 convalescent were significantly lower than ChAd/ BNT, BNT/BNT, ChAd/Chad and BNT1dose/CoV2. The proportion of subjects reaching an anti-S- RBD titer > 75 AU/ml, correlated high neutralizing titer, was of 94% in ChAd/BNT and BNT/BNT, 60% in BNT1dose/CoV2, 25% in ChAd/ChAd and 4.2% in convalescent. At T15Wthe titer of ChAd/BNT was still significantly higher than other vaccine schedules, while the anti-S- RBD decline was reduced for ChAd/ChAd and similar for other combinations. At T28W weeks) there was a significant difference of median ChAd/BNT vs ChAd/ Chad (p = 0.0166), with 36.11 AU/ml and 5.5 AU/ml, respectively. The decay of antispike antibody to RBD at 170 days was 1342 AU/ week for ChAd/ChAd, and 19.22 AU/week for ChAD/BNT. Conclusion(s): Our data highlight the magnitude of IgG anti-S- RBD response in the ChAd/BNT dosing and higher IgG levels were still detectable after 28 weeks after booster dose supporting the current national guidelines for heterologous boosting. The analysis of effectiveness of vaccine combinations in this cohort is ongoing, during the omicron variant spread.

A MECHATRONIC SIMULATOR OF AN AIRCRAFT COCKPIT TO STUDY, BY A VIRTUAL FLIGHT TEST, CARDIOVASCULAR FITNESS IN AIRLINE PILOTS BANNED TO FLY SINCE COVID-19 LOCKDOWN

During flying airline pilots cardio-vascular adaptations occur producing a steady condition of bradycardia and low values in arterial blood pressure. The ability to maintain this optimal level of cardiovascular fitness in aircraft pilots during a prolonged non-driving period is reduced proportionally to this interval. The COVID-19 pandemic has forced pilots to inactivity due to the interruption of many flights at the start of the pandemic. We tested the cardiovascular profile in seven skilled pilots, after 26 weeks of banned to flying for the pandemic lockdown, while they virtually drove an entirely self-built aircraft Airbus A320 simulator. The aim was to investigate on their possible circulatory impairments. Beat-to-beat cardiodynamic profile was non invasively and remotely assessed by a homemade impedance cardiography ICT platform, i.e. the e-Physio tool. Results showed an en route high mean arterial blood pressure (almost 104 Torr) mainly sustained by excessively high values of peripheral vascular resistance (more than 24 Torr per dm3 per minute). Properly central-cardiac hemodynamic and chronotropic modulators of the stroke volume (ventricle end diastolic volume and contractility, heart rate) did not change significantly. Since this hemodynamic picture resembles that of heart failure, it was concluded that (due to the covid-19 dependent long period of inactivity) pilots may go towards a condition of detraining that involved the loss of specific cardiovascular adaptations capable of buffering risks of arterial hypertension. © 2022, Levrotto and Bella. All rights reserved.

Verifying the Theory of Climate Affecting Lethality of COVID-19 by an Analysis in Two Climatic Zones of Chile

Introduction: The study of seasonal influences on the COVID-19 pandemic can take advantage of the unique position of Chile and its different climatic profiles in the north-south extension. The purpose is to verify the influence of seasonal climate changes on the COVID-19 in the temperate and sub-arctic areas of Chile. Methods: We monitored the evolution of CFR in temperate versus sub-boreal regions, reporting from the John Hopkins University COVID-19 Center on the CFR in each province in midwinter, spring, and early summer. Results: CFR worsened from mid-winter to mid-spring in the temperate zone of Chile, while in the sub-boreal area the CFR improves in the same period, (Kruskal Wallis Test, p=0.004). In the temperate zone after the increase in late winter-early spring, CRF tends to stabilize;on the contrary in the sub-boreal zone, there is a more marked tendency to worsen the CFR at the same time (Kruskal Wallis Test, p=0.010). The temperate zone of Chile shows a CFR increasing until spring-like temperate Europe, unlike Europe CFR does not decrease in summer, but the mean minimum temperature in temperate Chile is lower in summer than in temperate Europe. In Patagonian, CFR remains stable or drops from winter to spring but increases in early summer. Conclusion: The temperate and sub-boreal zones of Chile have a markedly different CFR variation profile during the COVID-19 pandemic.

The impact of death of COVID-19 patients on mental health of healthcare workers: a latent profile analysis of post-traumatic stress symptoms

Introduction. The COVID-19 pandemic crisis significantly impacted workplaces across the world. Healthcare workers (HCWs) had to promptly manage unpredictable daily severe critical patients, caring for severely traumatized patients, and frequent witnessing of death of patients. More recently, many studies highlighted how the large number of deaths and the way patients were dying significantly impacted mental health of HCWs, exposing them to the risk of developing post-traumatic stress (PTS) symptoms. The main purpose of this study was to explore subtypes of HCWs on the levels of PTS symptoms, considering those workers who cared for patients who died of COVID-19. Materials and Methods. An online survey was conducted using LimeSurvey. We applied latent profile analysis (LPA) to identify profiles of PTS symptoms in a sample of Italian HCWs (n=543). LPA including one to six latent profiles were estimated by using MPlus 7 robust maximum-likelihood estimator (MLR). Results. LPA showed a three-latent-profile solution: high-PTS symptoms (high levels of intrusion, avoidance, and hyperarousal;n=35), moderate-PTS (moderate levels of intrusion, avoidance, and hyperarousal;n=397), and low-PTS (low levels of intrusion, avoidance, and hyperarousal;n=111). Conclusions. To our knowledge, no studies have yet examined whether distinct subgroups of PTS symptoms can be identified among HCWs exposed to the death of COVID19 patients. Using person-centered methods for the identification of latent patterns of PTS symptoms may potentially have conceptual, diagnostic, and treatment implications.

COVID-19 case fatality ratio of Latino America countries with temperate climate partially follows european and oceania trends according to seasonal change

The objective of our study is, therefore, to verify whether the trend of the pandemic regarding the lethality of the virus is similar in Argentina and Chile to that which emerged in the temperate countries of Europe and Oceania. The CFRs were derived from the John Hopkins University database. To check the trend of the Case Fatality Ratio and Argentina, Chile we calculated this index on the same dates in which it was calculated for comparison in European countries and in Australia and New Zealand: i.e., May 6th and from May 6th to the September 21st. We continued comparing the other countries of the southern hemisphere, recalculating the CFR as of 11th November. For comparing a period of year homogeneous, late spring, we calculate the change if CFR from 20th March to 15th April in the North Hemisphere. Our study's results seem to confirm in Latin America a possible influence of the climate and the changing of the seasons in the lethality of the virus. For the same exceptions, it is evident that the study shows that this factor is not the only one nor probably the most important. The obvious exception concerns Argentina, which does not show any summer improvement of the CFR, unfortunately;for this, nation-specific data are not available to verify if the trend is homogeneous in the different climates that the vast territory presents. Other very important factors come into play, among which the diffusivity of the virus also seems to play a role. © 2020 by the authors.

The Climate in the European Union and the Enlarged European Region is a Determinant of the COVID-19 Case Fatality Ratio

Climate could influence the COVID-19 pandemic, but while no evidence has been advanced on the influence of colder climates, some studies have provided data to support a possible heat-related protective factor. The objective is to verify whether areas with a Cold Temperate Climate (TC) have a higher Case Fatality Ratio (CFR) for COVID-19 than areas with a Cold Climate (CC) or with a Mediterranean Climate (MC) in the European Union and the Enlarged European Region. Countries or regions were subdivided into 3 groups according to the Koppen climate classification system: TC (Cfa, Cfb and Cfc in the Koppen system);MC (Csa, Csb);CC (D and E in the Koppen system). The total number of cases and the total number of deaths were detected on 13 August 2020 on the COVID-19 Map-Johns Hopkins Coronavirus Resource Center-the CFR was thus calculated by area. Living in TC areas is strongly associated with risk of a high Case Fatality Ratio for COVID-19, OR for MC=0.42, IC 95% 0.41-0.43;OR for CC=0.33, IC 95% 0.33-0.35. The results are confirmed in the EU, OR per MC=0.85, CI 95% 0.84-0.87;OR per CC=0.63, IC 95% 0.61-0.65.The study found that the IC in a humid temperate climate is associated with higher CFR with respect to the coldest and warmest temperate climates in Europe. This does not appear to be the only determinant of the pandemic.

Vaccination against seasonal influenza and socio-economic and environmental factors as determinants of the geographic variation of COVID-19 incidence and mortality in the Italian elderly.

BACKGROUND: A possible protective effect of seasonal influenza vaccination against the spread of the COVID-19 epidemic has been suggested. METHODS: We used publicly available data bases to explore the hypothesis as well as the effect of multiple social and environmental factors in the 20 Italian regions. RESULTS: Our results suggest that vaccination against seasonal influenza might beneficially impact on incidence and severity of the novel corona virus epidemic. Population density and vehicular traffic were also moderately associated with cumulative incidence of COVID-19. None of the other variables we considered showed an effect on cumulative incidence, case fatality rate or mortality from COVID-19. CONCLUSIONS: Extending influenza vaccination coverage particularly among the elderly, vulnerable individuals with specific chronic medical conditions, health care workers, and workers in other essential services, early in the upcoming 2020 influenza season, might help reduce the health impact of a second epidemic wave of COVID-19.

Is the inversion in the trend of the lethality of the covid-19 in the two hemispheres due to the difference in seasons and weather?

The climate has an influence on the COVID-19 virus lethality. The aim of this study is to verify if the summer weather coincided with the decrease of the Case Fatality Ratio (CFR) in Europe and if, on the contrary, an inverse trend was observed in Australia and New Zealand. To verify our hypothesis, we considered the largest European countries (Germany, UK, France, Italy, and Spain), plus Belgium and the Netherlands. Furthermore, we compared these countries with Australia and New Zealand. For each country considered, we have calculated the CFR from the beginning of the pandemic to May 6th and from May 6th to September 21st (late summer in Europe, late winter in the southern hemisphere). The CFRs were calculated from the John Hopkins University database. According to the results, in all European countries, a progressive decrease in CFR is observed. A diametrically opposite result is found in Australia where, on the contrary, the CFR is much higher at the end of September (at the end of winter) than on May 6th (mid-autumn), and the risk of dying if we count the infection is higher in September. In New Zealand, there are no statistically significant differences between the two surveys. The present study was based on public access macro data. © 2020 by the authors.