ABSTRACT
COVID-19 has emerged as a devastating pandemic of the century that the current genera-tions have ever experienced. The COVID-19 pandemic has infected more than 12 million people around the globe, and 0.5 million people have succumbed to death. Due to the lack of effective vaccines against the COVID-19, several nations throughout the globe have imposed a lock-down as a preventive measure to lower the spread of COVID-19 infection. As a result of lock-down, most of the universities and research institutes have witnessed a long pause in basic science research ever. Much has been discussed about the long-term impact of COVID-19 on the economy, tourism, public health, small and large-scale businesses of several kinds. However, the long-term effects of the shut-down of these research labs and their impact on basic science research has not been much focused. Herein, we provide a perspective that portrays a common problem of all the basic science researchers throughout the globe and its long-term consequences.Copyright © 2021 Bentham Science Publishers.
ABSTRACT
Aims: Healthcare workers are at increased risk of SARS-CoV-2 infection and were among the first to be vaccinated against the virus. We aimed to estimate the level and duration of protection the vaccines provide against infection by monitoring the humoral immune response mounted after each vaccination. Method(s): 177 and 102 respiratory health professionals were recruited before receiving initial Pfizer-Biontech and booster vaccines, respectively. Serum levels of RBD-specific IgG antibodies were measured at various time points;the unit of measurement was signal/cut-off (S/CO). Result(s): In previously uninfected participants, IgG production was slow to start in response to the first vaccination and only reached the positive range shortly before the second vaccination on day 21. Following the first vaccination, IgG production peaked on day 28, whereas following the booster vaccination IgG levels peaked more rapidly but at a significantly lower level (43.7 vs. 22.0 S/CO, p<0.0001). Stratification by sex and mean age showed no difference in maximum IgG levels. In most participants, IgG levels declined rapidly after both the initial and booster vaccination, but 4 months after vaccination, the booster vaccine provided a significantly higher proportion of circulating IgG compared to the maximum level (30.6% vs. 21.9%). The number of COVID-positive cases 4 months after vaccination was higher for the booster vaccine. Conclusion(s): Based on IgG titers, the Pfizer-Biontech booster vaccine appears to provide a longer-lasting humoral immune response compared to the first vaccination, but this may still confer less protection against new virus variants.
ABSTRACT
Background: SARS-CoV-2 vaccines are expected to induce both cellular and humoral immune responses, however, the dynamics and correlation between the two types of immunity are not precisely understood. Aim(s): Assessing IgG levels and T-cell response induced by SARS-CoV-2 vaccines and investigating the correlation between cellular and humoral immune responses. Method(s): Blood samples were taken from 166 respiratory healthcare professionals at four time-points: first before administering the booster vaccine, then on day 28, 56 and 120 post-vaccination. For the assessment of humoral immune response anti-Spike protein IgG ELISA was used, while T-cell response was tested by interferon-gammarelease-assay. Result(s): Out of 166 patients, 120 individuals presented positive result for interferon-gamma, while 100 had positive results for IgG. The positivity rate of cellular immune response was found to be significantly higher than humoral between the second and third doses of anti-COVID vaccines (P<0,05). Participants, who have had SARS-CoV-2 infection before the first two shots, the immune response was detectable at a statistically higher rates than in the COVID naive group. The third dose triggered different dynamics regarding the IgG titers and T-cell response. Four months after the administration of the booster shot both humoral and cellular immune response were detectable simultaneously. Conclusion(s): After the first two doses, the cellular immune response was found to last longer than humoral, especially in previously infected individuals. Measuring the T-cell responses to SARS-CoV-2 vaccines may complement the antibody tests currently used in clinical practice.
ABSTRACT
In adults, COVID-19 infection increases the risk of thrombotic events. Hospitals worldwide reported a poorer prognosis for patients who did not receive venous thromboembolism (VTE) prophylaxis, in comparison to those who did. This finding instigated UK hospitals to form their own local policies on VTE prophylaxis in COVID-19 positive patients, to prevent death and complications secondary to clot formation. Due to older age, multiple co-morbidities, decreased mobility and increased frailty, nursing home residents with confirmed COVID-19 have an increased thrombotic risk. Therefore, a primary thromboprophylactic (TP) strategy was formulated (see figure 1) and applied to COVID-19 positive residents in Islington nursing homes. This included the prescribing of apixaban 2.5 mg twice daily if there were no contraindications. The guideline included a risk versus benefit assessment tool, prescribing advice and monitoring recommendations. It was also stated that the prescribing of apixaban for this indication would be considered as off-label use. The guideline was amended following the role out of the COVID-19 vaccination programme with the addition of 'residents who have been doubly vaccinated and become COVID positive but are asymptomatic will not require VTE prophylaxis as the vaccines have demonstrated some protection against severe illness from COVID-19'. The aim of this service evaluation is to review the implementation of this thromboprophylactic strategy. This included the number of residents prescribed TP, the incidence of bleeding or thrombotic complications, as well as number of deaths relating to COVID-19. Data were retrospectively collected from six nursing homes between November 2020 and April 2021 from GP electronic medical records (EMIS). Fifty-one residents tested positive for COVID-19 during this time. Six deceased residents were eliminated from the audit as their electronic records were not available to determine thromboprophylactic status. Additionally, two residents were excluded as they were admitted to hospital and 12 residents were already in receipt of anticoagulation. The 12 residents who were already prescribed anticoagulation prior to their positive COVID test were on anticoagulation for the treatment of AF. From these 12 residents, three died with COVID-19 reported on their death certificates. Of the 31 residents included, there were 12 males and 19 [SZ4] females and the median age was 79 years (range: 46-101). All residents had at least one co-morbidity which would increase their VTE risk. Twenty-three (74%) residents were prescribed TP in line with the guidelines. Of these, three died from COVID-19. The remaining eight residents were not prescribed TP. Of these eight, two died from COVID-19. The most common reasons for not prescribing thromboprophylaxis included residents on end-of-life care, high bleeding risk or lack of locum GP awareness of the guidelines. There were no reported bleeding events in residents prescribed TP. There were no thrombotic events in residents prescribed TP. The accuracy of the cause of death recorded for the deceased residents was limited, due to the absence of postmortem examinations. The numbers of residents included in this audit was too small to provide statistical relevance. Apixaban may be a safe option for residents in nursing homes who are COVID-19 positive and are considered to have a high risk of thrombosis..