Of Cross-immunity, Herd Immunity and Country-specific Plans: Experiences from COVID-19 in India

The effect of the earliest COVID-19 outbreak on survival in uninfected advanced NSCLC patients receiving chemotherapy in Jiangsu Province, China: A retrospective cohort study

Coronavirus disease 2019 (COVID-19) is still rampant and uncontrolled across the globe. China's strict epidemic prevention measures have had an impact on the treatment in patients with non-small cell lung cancer (NSCLC). The aim of this study is to explore the impact of the COVID-19 outbreak on the uninfected NSCLC patients. The chemotherapeutic efficacy and survival of 89 uninfected advanced NSCLC patients were retrospectively analyzed. The endpoints were overall survival (OS), progression-free survival (PFS), and response rate. Forty and forty-nine patients with advanced NSCLC received chemotherapy during the COVID-19 outbreak and nonoutbreak periods, respectively. Mean delay time was 12.8 months for COVID-19 outbreak stage versus 5.68 months for nonoutbreak stage (P = .003). There was no significant difference in the rates of chemotherapy delay and discontinuation between the 2 groups (P = .055 and .239). Significant difference was not detected in median OS (15.8 months) for COVID-19 outbreak stage versus 16.0 months for nonoutbreak stage (adjusted hazard ratio, 1.058; 95% confidence interval, 0.593-1.888; P = .849); Median PFS was 7.9 months for COVID-19 outbreak stage versus 10.3 months for nonoutbreak stage (adjusted hazard ratio, 0.878; 95% confidence interval 0.513-1.503; P = .634). There was also no statistical difference in the disease control rate between the 2 groups (P = .137). The earliest COVID-19 outbreak had no significant impact on the PFS and OS in uninfected advanced NSCLC patients receiving chemotherapy. However, the mean delay time of receiving chemotherapy was prolonged during the COVID-19 outbreak.

The COVID-19 pandemic in sub-Saharan Africa: The significance of presumed immune sufficiency

A novel coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was first reported in China in 2019 and later ignited a global pandemic. Contrary to expectations, the effect of the pandemic was not as devastating to Africa and its young population compared to the rest of the world. To provide insight into the possible reasons for the presumed immune sufficiency to coronavirus disease 2019 (COVID-19) in Africa, this review critically examines literature published from 2020 onwards on the dynamics of COVID-19 infection and immunity and how other prevalent infectious diseases in Africa might have influenced the outcome of COVID-19. Studies characterising the immune response in patients with COVID-19 show that the correlates of protection in infected individuals are T-cell responses against the SARS-CoV-2 spike protein and neutralising titres of immunoglobin G and immunoglobin A antibodies. In some other studies, substantial pre-existing T-cell reactivity to SARS-CoV-2 was detected in many people from diverse geographical locations without a history of exposure. Certain studies also suggest that innate immune memory, which offers protection against reinfection with the same or another pathogen, might influence the severity of COVID-19. In addition, an initial analysis of epidemiological data showed that COVID‑19 cases were not severe in some countries that implemented universal Bacillus Calmette-Guerin (BCG) vaccination policies, thus supporting the potential of BCG vaccination to boost innate immunity. The high burden of infectious diseases and the extensive vaccination campaigns previously conducted in Africa could have induced specific and non-specific protective immunity to infectious pathogens in Africans.

Analyzing the attitude of Indian citizens during the second wave of COVID-19: A text analytics study

BACKGROUND AND AIMS

The COVID-19 pandemic outbreak has created severe public health crises and economic consequences across the globe. This study used text analytics techniques to investigate the key concerns of Indian citizens raised in social media during the second wave of COVID-19.

METHODS

In this study, we performed a sentiment and emotion analysis of tweets to understand the attitude of Indian citizens during the second wave of COVID-19. Moreover, we performed topic modeling to understand the significant issues and concerns related to COVID-19.

RESULTS

Our results show that most social media posts were in neutral tone, and the percentage of posts that showed positive sentiment was less. Furthermore, emotion analysis results show that 'Fear' and 'Surprise' were the prominent emotions expressed by the citizens. Topic modeling results reveal that 'High crowd' and 'political rallies' are the two primary topics of concern raised by Indian citizens during the second wave of COVID-19.

CONCLUSIONS

Hence, Indian government agencies should communicate crisis information and combating strategies to citizens more effectively in order to minimize the fear and anxiety amongst the public.

Challenges in Establishing Vaccine Induced Herd Immunity through Age Specific Community Vaccinations

Presently, the second wave of COVID-19 pandemic is driving the world towards a devastating total failure of the healthcare system. The purpose of the review is to search for the studies reporting on the implication of herd immunity into a naïve population through age specific mass vaccination. This review is based on selected publications on the effect herd immunity to COVID 19 in communities. We searched published scientific articles, review articles, reports, published in 2020 as well as read some basic, cult publications related to establishment of indirect immunity to a population. We have focused on use of application of vaccine induced herd immunity into community to confer indirect immunity against COVID-19 and searched on electronic databases, including PubMed (http://www.pubmed.com), Scopus (http://www.scopus.com), Google Scholar (http://www.scholar.google.com), Web of Science (www.webofscience.com) and Science Direct by using key words such as Herd immunity, indirect or passive immunization, Coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome, coronavirus 2 (SARS-CoV-2), and immune-technique. This review proposes the implication of mass vaccination-induced herd immunity in a population to curb the infection, and to every individual in a given population irrespective of their age.

Single-Cell Immunogenomic Approach Identified SARS-CoV-2 Protective Immune Signatures in Asymptomatic Direct Contacts of COVID-19 Cases

The response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is largely impacted by the level of virus exposure and status of the host immunity. The nature of protection shown by direct asymptomatic contacts of coronavirus disease 2019 (COVID-19)-positive patients is quite intriguing. In this study, we have characterized the antibody titer, SARS-CoV-2 surrogate virus neutralization, cytokine levels, single-cell T-cell receptor (TCR), and B-cell receptor (BCR) profiling in asymptomatic direct contacts, infected cases, and controls. We observed significant increase in antibodies with neutralizing amplitude in asymptomatic contacts along with cytokines such as Eotaxin, granulocyte-colony stimulating factor (G-CSF), interleukin 7 (IL-7), migration inhibitory factor (MIF), and macrophage inflammatory protein-1α (MIP-1α). Upon single-cell RNA (scRNA) sequencing, we explored the dynamics of the adaptive immune response in few representative asymptomatic close contacts and COVID-19-infected patients. We reported direct asymptomatic contacts to have decreased CD4⁺ naive T cells with concomitant increase in CD4⁺ memory and CD8⁺ Temra cells along with expanded clonotypes compared to infected patients. Noticeable proportions of class switched memory B cells were also observed in them. Overall, these findings gave an insight into the nature of protection in asymptomatic contacts.

Mesenchymal stem cell treatment improves outcome of COVID-19 patients via multiple immunomodulatory mechanisms

The infusion of coronavirus disease 2019 (COVID-19) patients with mesenchymal stem cells (MSCs) potentially improves clinical symptoms, but the underlying mechanism remains unclear. We conducted a randomized, single-blind, placebo-controlled (29 patients/group) phase II clinical trial to validate previous findings and explore the potential mechanisms. Patients treated with umbilical cord-derived MSCs exhibited a shorter hospital stay (P = 0.0198) and less time required for symptoms remission (P = 0.0194) than those who received placebo. Based on chest images, both severe and critical patients treated with MSCs showed improvement by day 7 (P = 0.0099) and day 21 (P = 0.0084). MSC-treated patients had fewer adverse events. MSC infusion reduced the levels of C-reactive protein, proinflammatory cytokines, and neutrophil extracellular traps (NETs) and promoted the maintenance of SARS-CoV-2-specific antibodies. To explore how MSCs modulate the immune system, we employed single-cell RNA sequencing analysis on peripheral blood. Our analysis identified a novel subpopulation of VNN2⁺ hematopoietic stem/progenitor-like (HSPC-like) cells expressing CSF3R and PTPRE that were mobilized following MSC infusion. Genes encoding chemotaxis factors - CX3CR1 and L-selectin - were upregulated in various immune cells. MSC treatment also regulated B cell subsets and increased the expression of costimulatory CD28 in T cells in vivo and in vitro. In addition, an in vivo mouse study confirmed that MSCs suppressed NET release and reduced venous thrombosis by upregulating kindlin-3 signaling. Together, our results underscore the role of MSCs in improving COVID-19 patient outcomes via maintenance of immune homeostasis.

South Asian Declaration-Consensus Guidelines for COVID-19 Vaccination in Cancer Patients

We provide the South Asian Declaration, containing the consensus guidelines for coronavirus disease 2019 (COVID-19) vaccination in cancer patients.

A prospective observational safety study on ChAdOx1 nCoV-19 corona virus vaccine (recombinant) use in healthcare workers- first results from India

BACKGROUND

We provide the first post-approval safety analysis of COVISHIELD in health care workers (HCWs) in northern India.

METHODS

This continuing prospective observational study (February 2021 to May 2022) enrolled participants ≥18 years receiving COVISHIELD vaccination. Primary outcome was safety and reactogenicity. Categories (FDA toxicity grading) and outcomes of adverse events following immunization (AEFIs) were recorded, causality assessment performed, and risk factors analysed.

FINDINGS

We present the results of an interim analysis of 804 participants. AEFIs following first dose were reported in 321 (40%; systemic involvement in 248). Among 730 participants who completed a 7-day follow-up post second dose, AEFIs occurred in 115 (15.7%; systemic in 99). Majority of AEFIs were mild-moderate and resolved spontaneously. Serious AEFIs, leading to hospitalization was noticed in 1 (0.1%) participant with suspicion of immunization stress related response (ISRR). AEFIs of grade 3 severity (FDA) were recorded in 4 participants (0.5%). No deaths were recorded. Regression analysis showed increased risk of AEFIs in younger individuals, a two times higher odds in females, those with hypertension or with history of allergy; and three times higher odds in individuals with hypothyroidism.

INTERPRETATION

COVISHIELD carries an overall favourable safety profile with AEFI rates much less than reported for other adenoviral vaccines. Females, those with hypertension, individuals with history of allergy and hypothyroidism may need watchful vaccine administration. This being an interim analysis and based on healthcare workers who may not reflect the general population demographics, larger inclusive studies are warranted for confirming the findings.

FUNDING

No funding support.

Characteristics of COVID-19 Recurrence: A Systematic Review and Meta-Analysis

Background:

Previous studies reported the recurrence of coronavirus disease 2019 (COVID-19) among discharge patients. This study aimed to examine the characteristic of COVID-19 recurrence cases by performing a systematic review and meta-analysis.

Methods:

A systematic search was performed in PubMed and Embase and gray literature up to September 19, 2020. A random-effects model was applied to obtain the pooled prevalence of disease recurrence among recovered patients and the prevalence of subjects underlying comorbidity among recurrence cases. The other characteristics were calculated based on the summary data of individual studies.

Results:

A total of 41 studies were included in the final analysis, we have described the epidemiological characteristics of COVID-19 recurrence cases. Of 3,644 patients recovering from COVID-19 and being discharged, an estimate of 15% (95% CI, 12% to 19%) patients was re-positive with SARS-CoV-2 during the follow-up. This proportion was 14% (95% CI, 11% to 17%) for China and 31% (95% CI, 26% to 37%) for Korea. Among recurrence cases, it was estimated 39% (95% CI, 31% to 48%) subjects underlying at least one comorbidity. The estimates for times from disease onset to admission, from admission to discharge, and from discharge to RNA positive conversion were 4.8, 16.4, and 10.4 days, respectively.

Conclusion:

This study summarized up-to-date evidence from case reports, case series, and observational studies for the characteristic of COVID-19 recurrence cases after discharge. It is recommended to pay attention to follow-up patients after discharge, even if they have been in discharge quarantine.

COVID-19: Is herd immunity the only option for fragile Yemen?

The first case of COVID-19 in Yemen was confirmed on 10 April 2020. Having faced with a six-year long conflict that has destroyed half of its healthcare facilities and displaced millions, predictions of infections and mortality in Yemen suggested a looming healthcare catastrophe. Difficulty in implementing coordinated lockdowns and preventive measures due to the daily labor working nature of the majority of the population, provided the perfect breeding ground for the SARS-CoV-2 virus. However, official figures of infections and mortality are very low and there have not been confirmed reports of excess mortality. This could indicate that Yemen is silently marching towards forced herd immunity. Seroprevalence studies will provide useful insight into the COVID-19 transmission trajectory in Yemen, which can serve as a guide in planning vaccine distribution strategies and allocating the limited funds wisely.