Omicron – The new SARS‐CoV‐2 challenge?

Abstract

SARS‐CoV‐2 virus has infected nearly 300 M people worldwide and has been associated with over 6 M deaths by March 2022. Since the virus emergence in December 2019 in Wuhan, several new mutations have been described. The World Health Organization has developed a working name for these emerging variants according to their impact on the worldwide population. In this context a high alert has been paid to variants of concern (VOC) due to their high infectiousness and transmissibility patterns. The most recent VOC, Omicron (B.1.1.529), has become dominant in the shortest time ever and has placed Europe under an overwhelming and unprecedented number of new cases. This variant has numerous mutations in regions that are associated with higher transmissibility, stronger viral binding, affinity and antibody escape. Moreover, the mutations and deletions present in the spike protein suggest that the SARS‐CoV‐2 specific attachment inhibitors may not be the best option for Omicron therapy. Omicron is the dominant variant circulating worldwide and, at the end of February 2022, it was responsible for nearly all sequences reported to GISAID. Omicron is made up of several sublineages, where the most common are BA.1 and BA.2 (or Nextstrain clade 21K and 21L, respectively). At a global level, it is possible to say that the proportion of BA.2 has been increasing relative to BA.1 and in some countries it has been replacing it at high rates. In order to better assess the Omicron effectiveness on antibody escape, spread and infectious ability it is of the highest relevance to maintain a worldwide tight surveillance. Even though this variant has been associated with a lower death rate, it is important to highlight that the number of people becoming infected is concerning and that further unpredictable mutations may emerge as the number of infected people rises.

SARS‐CoV‐2 Omicron BA.1 variant breakthrough infections in nursing home residents after an homologous third dose of the Comirnaty® COVID‐19 vaccine: Looking for correlates of protection

“…The SARS‐CoV‐2 Omicron variant has become dominant in many countries 1 due to its increased transmissibility compared to the Delta variant, owing at least partly to its remarkable ability to escape from SARS‐CoV‐2 Spike (S) neutralizing antibodies (NtAb) elicited during natural infection or after vaccination with regular or booster schedules. 2 , 3 , 4 , 5 Adaptive immunity is critically involved in preventing SARS‐CoV‐2 infection 6 ; nevertheless, protective thresholds remain elusive for both S‐binding NtAb and T cells.…”

Effectiveness and safety analysis of SanHanHuaShi granules for the treatment of coronavirus disease 2019: Study protocol and statistical analysis plan for a randomized, parallel-controlled, open-label clinical trial

“…The ongoing COVID-19 pandemic, which has been spreading for more than two years, has led to various variants of SARS-CoV-2 ( Tao et al, 2021 ; Khandia et al, 2022 ). The increased transmissibility or severity of SARS-CoV-2 continually poses serious challenges to vaccine development and targeted therapeutic strategies ( Dong et al, 2021 ; Lino et al, 2022 ). Timely intervention with TCM in COVID-19 has been shown to significantly relieve symptoms, shorten the course, and improve the prognosis of the disease An et al, 2021 .…”

The role transition of radiotherapy for the treatment of liver cancer in the COVID-19 era

“…It is unclear whether Omicron BA.2, BA.4, or BA.5 will trigger a new epidemic peak. It is also unclear whether new-type and more dangerous variants of SARS-CoV-2 will appear based on the large base of global COVID-19 patients ( 37 , 38 ). However, it is definitely clear that more than six million deaths at least were directly caused by COVID-19, which should not be overlooked as an inanimate number ( 1 , 4 ).…”