A comparative analysis on the safety and efficacy of Covaxin versus other vaccines against COVID-19: a review

Ocular Implications of COVID-19 Infection and Vaccine-Related Adverse Events

The COVID-19 pandemic, caused by SARS-CoV-2, has significantly impacted various organ systems, including the eyes. Initially considered a primarily respiratory disease, it is now evident that COVID-19 can induce a range of ocular symptoms. Recognizing these ocular manifestations is crucial for eye care practitioners as they can serve as early indicators of the disease. This review consolidates current evidence on the ocular effects of COVID-19, identifying manifestations such as conjunctivitis, scleritis, uveitis, and retinopathy. The increasing prevalence of these symptoms highlights the importance of thorough eye examinations and detailed patient histories in COVID-19 cases. Potential routes of viral entry into ocular tissues and the underlying mechanisms, including direct infection, immune responses, and vascular involvement, are explored. Additionally, this review addresses ocular side effects associated with COVID-19 vaccines, such as corneal graft rejection, uveitis, and retinal issues. These findings emphasize the need for ongoing surveillance and research to ensure vaccine safety.

Challenges in Emerging Vaccines and Future Promising Candidates against SARS-CoV-2 Variants

Since the COVID-19 outbreak, the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) virus has evolved into variants with varied infectivity. Vaccines developed against COVID-19 infection have boosted immunity, but there is still uncertainty on how long the immunity from natural infection or vaccination will last. The present study attempts to outline the present level of information about the contagiousness and spread of SARS-CoV-2 variants of interest and variants of concern (VOCs). The keywords like COVID-19 vaccine types, VOCs, universal vaccines, bivalent, and other relevant terms were searched in NCBI, Science Direct, and WHO databases to review the published literature. The review provides an integrative discussion on the current state of knowledge on the type of vaccines developed against SARS-CoV-2, the safety and efficacy of COVID-19 vaccines concerning the VOCs, and prospects of novel universal, chimeric, and bivalent mRNA vaccines efficacy to fend off existing variants and other emerging coronaviruses. Genomic variation can be quite significant, as seen by the notable differences in impact, transmission rate, morbidity, and death during several human coronavirus outbreaks. Therefore, understanding the amount and characteristics of coronavirus genetic diversity in historical and contemporary strains can help researchers get an edge over upcoming variants.

Demographics and Clinical Characteristics of COVID-19-vaccinated Patients Admitted to ICU: A Multicenter Cohort Study from India (PostCoVac Study-COVID Group)

Background

Emergency authorization and approval were given for the coronavirus disease-19 (COVID-19) vaccines. The efficacy reported after phase III trials were 70.4% and 78% for Covishield and Covaxin, respectively.In this study, we aim to analyze the risk factors, which were associated with mortality in critically ill COVID-19-vaccinated patients admitted into intensive care unit (ICU).

Materials and methods

This study was conducted from April 1, 2021 to December 31, 2021 across five centers in India. Patients who had received either one or two doses of any of the COVID vaccines and developed COVID-19 were included. The ICU mortality was a primary outcome.

Results

A total of 174 patients with COVID-19 illness were included in the study. The mean age was 57 years standard deviation (SD 15). Acute physiology, age and chronic health evaluation (APACHE II) score and the sequential organ failure assessment (SOFA) score were 14 (8-24.5) and 6 (4-8), respectively. Multiple variable logistic regression showed patients who have received a single dose [odds ratio (OR): 2.89, confidence interval (CI): 1.18, 7.08], neutrophil:lymphocyte (NL) ratio (OR: 1.07, CI: 1.02,1.11), and SOFA score (OR: 1.18, CI: 1.03,1.36) were associated with higher mortality.

Conclusion

The mortality in the vaccinated patients admitted to the ICU was 43.68% due to COVID illness. The mortality was lower in patients who had received two doses.

How to cite this article

Havaldar AA, Prakash J, Kumar S, Sheshala K, Chennabasappa A, Thomas RR et al. Demographics and Clinical Characteristics of COVID-19-vaccinated Patients Admitted to ICU: A Multicenter Cohort Study from India (PostCoVac Study-COVID Group). Indian J Crit Care Med 2022;26(11):1184-1191.

Immune Response to SARS-CoV-2 Vaccines

COVID-19 vaccines have been developed to confer immunity against the SARS-CoV-2 infection. Prior to the pandemic of COVID-19 which started in March 2020, there was a well-established understanding about the structure and pathogenesis of previously known Coronaviruses from the SARS and MERS outbreaks. In addition to this, vaccines for various Coronaviruses were available for veterinary use. This knowledge supported the creation of various vaccine platforms for SARS-CoV-2. Before COVID-19 there are no reports of a vaccine being developed in under a year and no vaccine for preventing coronavirus infection in humans had ever been developed. Approximately nine different technologies are being researched and developed at various levels in order to design an effective COVID-19 vaccine. As the spike protein of SARS-CoV-2 is responsible for generating substantial adaptive immune response, mostly all the vaccine candidates have been targeting the whole spike protein or epitopes of spike protein as a vaccine candidate. In this review, we have compiled the immune response to SARS-CoV-2 infection and followed by the mechanism of action of various vaccine platforms such as mRNA vaccines, Adenoviral vectored vaccine, inactivated virus vaccines and subunit vaccines in the market. In the end we have also summarized the various adjuvants used in the COVID-19 vaccine formulation.