SARS-CoV-2 Infection: New Molecular, Phylogenetic, and Pathogenetic Insights. Efficacy of Current Vaccines and the Potential Risk of Variants

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a newly discovered coronavirus responsible for the coronavirus disease 2019 (COVID-19) pandemic. COVID-19 has rapidly become a public health emergency of international concern. Although remarkable scientific achievements have been reached since the beginning of the pandemic, the knowledge behind this novel coronavirus, in terms of molecular and pathogenic characteristics and zoonotic potential, is still relatively limited. Today, there is a vaccine, or rather several vaccines, which, for the first time in the history of highly contagious infectious diseases that have plagued mankind, has been manufactured in just one year. Currently, four vaccines are licensed by regulatory agencies, and they use RNA or viral vector technologies. The positive effects of the vaccination campaign are being felt in many parts of the world, but the disappearance of this new infection is still far from being a reality, as it is also threatened by the presence of novel SARS-CoV-2 variants that could undermine the effectiveness of the vaccine, hampering the immunization control efforts. Indeed, the current findings indicate that SARS-CoV-2 is adapting to transmission in humans more efficiently, while further divergence from the initial archetype should be considered. In this review, we aimed to provide a collection of the current knowledge regarding the molecular, phylogenetic, and pathogenetic insights into SARS-CoV-2. The most recent findings obtained with respect to the impact of novel emerging SARS-CoV-2 variants as well as the development and implementation of vaccines are highlighted.

COVID-19 Vaccine Hesitancy and Resistance in India Explored through a Population-Based Longitudinal Survey

“…India has a population of over 1390 million people. The government has presently recommended all its citizens within the inclusion criteria to be immunized by the two vaccines, namely the Covishield (the World Health Organization (WHO)-approved Astra Zeneca vaccine) and Covaxin (approved by India's drug-regulator and locally manufactured by Bharat Biotech) [7,8]. The Indian government has developed and approved urgent vaccine-related infrastructure and provided efficient digital information centers to address and observe the effectiveness and hesitancies of the Coronavirus disease 2019 (COVID-19) vaccination program.…”

“…The virus infectivity within the population can be retarded by adequate vaccination coverage. Estimates suggest that to achieve herd immunity when a vaccine is 100% effective, 67% of the population needs to be vaccinated [6,7]. However, with the presently available vaccines with 80-85% effectiveness, 75% vaccine coverage is required to ensure COVID-19 elimination and control within the population [12].…”

Responses to SARS-CoV-2 Vaccination in Patients with Cancer (ReCOVer Study): A Prospective Cohort Study of the Hellenic Cooperative Oncology Group

“…However, even these patients were not analysed separately to provide information on the safety and efficacy of the vaccines [14][15][16]. A lower response to vaccination was observed in solid organ transplant recipients and, more recently, in patients with hematologic malignancies [17][18][19].…”

Epigenetic Dysregulations in Merkel Cell Polyomavirus-Driven Merkel Cell Carcinoma

“…In conclusion, understanding epigenetic mechanisms, players, and connections in order to improve diagnosis, prognosis, and therapy in MCPyV-driven MCC is promising yet challenging. Identifying novel robust epigenetic markers such as HPTMs, methylated DNA sequences/genes, and differentially expressed miRNAs may improve early diagnosis, patient monitoring, and therapy of virus-related diseases [ 160 , 161 , 162 ], including MCPyV-driven MCC. Investigations into the epigenetic mechanisms behind MCPyV-driven MCC represent a relevant future area of study.…”