Current scenario of COVID-19 vaccinations and immune response along with antibody titer in vaccinated inhabitants of different countries

Int Immunopharmacol. 2021 Oct:99:108050. doi: 10.1016/j.intimp.2021.108050. Epub 2021 Aug 6.

Abstract

The COVID-19 pandemic challenges have been only partially addressed so far. The pathogenicity of SARS-CoV-2 is considered the combination of severe and high infectivity. Herdimmunity is attained when a critical proportion of the population is immune, providing the virus with fewer chances to spread locally. To overcome the rising tide of the COVID-19 pandemic, efficacious and safe vaccines providing defensive and long-lasting immunity responses are urgently needed.Vaccines that induce virus-neutralizing antibodies with great affinity can optimally fight against infection. Worldwide, over 120 novel vaccine candidates, including live-attenuated, inactivated, viral-vectored nonreplicating and replicating, peptide- and protein-based, and nucleic acid-based approaches are in the process of preclinical and clinical trials (phase 1-4). In addition to comprehensive safety assessments and immune responses, precise clinical management is also important for trials of vaccines. The recent emergence of different variants of SARS-CoV-2 is becoming a new threat for the world and a challenge for scientists to introduce the most influential vaccine against COVID-19. The possibility of natural and vaccine-induced immunity in variants finds it necessary to establish next-generation vaccines, which generate general neutralization against existing and future variants. Here, we summarize the cellular and humoral responses of SARS-CoV-2, current progress in vaccination development, the antibody titer response of available phase 4 vaccinations in vaccinated populations of different countries worldwide, and the success and challenges ahead of vaccine development.

Keywords: Adaptive immunity; Antibody titer; COVID-19; Cellular immunity; SARS-CoV-2; SARS-CoV-2 variants; Vaccination.

Publication types

  • Review

MeSH terms

  • COVID-19 / prevention & control*
  • COVID-19 Serological Testing
  • COVID-19 Vaccines / therapeutic use*
  • Humans
  • Immunity / immunology
  • Pandemics / prevention & control*
  • SARS-CoV-2
  • Vaccination

Substances

  • COVID-19 Vaccines