Implication of the emergence of the delta (B.1.617.2) variants on vaccine effectiveness.

Jaffar A Al-Tawfiq, Thoyaja Koritala, Saad Alhumaid, Mazin Barry, Abeer N Alshukairi, Mohamad-Hani Temsah, Abbas Al Mutair, Ali Rabaan, Raghavendra Tirupathi, Philippe Gautret

Journal: Infection 2022;50(3):583-596

PMID: 35113351

Free Full Text on PubMed Central View on PubMed

Abstract

INTRODUCTION

COVID-19 vaccines have been developed to compact the current SARS-CoV-2 pandemic and have been administered to people all over the world. These vaccines have been quite effective in reducing the possibility of severe illness, hospitalization and death. However, the recent emergence of Variants of Concern specifically the delta variant, B.1.617.2, had resulted in additional waves of the pandemic.

METHODS

We aim to review the literature to understand the transmission and disease severity, and determine the efficacy of the current COVID-19 vaccines. We searched Pubmed, Scopus, and Embase till August 4th 2021, and used the search terms "delta variant", "vaccinations"," breakthrough infections", and "neutralizing antibody". For the meta-analysis, 21 studies were screened in particular and five articles (148,071 cases) were included in the study, and only four were analyzed in the meta-analysis.

RESULTS

In this review, both in vitro and in vivo studies showed significant reductions in neutralization rates against delta variants for vaccinated individuals and convalescent patients with prior history of COVID-19. However, There was a lower incidence of infection with SARS-CoV-2 due to Delta variant was found after the second dose of Pfizer-BioNTech, Oxford-AstraZeneca and Moderna vaccines.

CONCLUSION

In fully vaccinated individuals, symptomatic infection with the delta variant was significantly reduced, and therefore, vaccinations play an important role to assist the fight against delta variant.

Address: Infectious Disease Unit, Specialty Internal Medicine, Dhahran Health Center, Johns Hopkins Aramco Healthcare, Rm A-420, Building 61, P.O. Box 76, Dhahran, 31311, Saudi Arabia. [email protected].; Infectious Diseases Unit, Department of Medicine, Indiana University School of Medicine, Indianapolis, IN, USA. [email protected].; Infectious Diseases Unit, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA. [email protected].; Department of Internal Medicine, Mayo Clinic Health System, Mankato, MN, USA.; Aministration of Pharmaceutical Care, Alahsa Health Cluster, Ministry of Health, Alahsa, Saudi Arabia.; Division of Infectious Diseases, Department of Internal Medicine, College of Medicine, King Saud University and King Saud University Medical City, Riyadh, Saudi Arabia.; Division of Infectious Diseases, Faculty of Medicine, University of Ottawa, Ottawa, Canada.; Department of Medicine, King Faisal Specialist Hospital and Research Center, Jeddah, Saudi Arabia.; Pediatric Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia.; Research Center, Almoosa Specialist Hospital, Alahsa, Saudi Arabia.; School of Nursing, Wollongong University, Wollongong, Australia.; College of Nursing, Princess Norah Bint Abdul Rahman University, Riyadh, Saudi Arabia.; Molecular Diagnostics Laboratory, Johns Hopkins Aramco Healthcare, Dhahran, Saudi Arabia.; Department of Public Health and Nutrition, The University of Haripur, Haripur, Pakistan.; Department of Medicine Keystone Health, Penn State University School of Medicine, Hershey, PA, USA.; Department of Medicine Wellspan Chambersburg and Waynesboro Hospitals, Penn State, Chambersburg, PA, USA.; Aix Marseille Univ, IRD, AP-HM, SSA, VITROME, Marseille, France.; IHU-Méditerranée Infection, Marseille, France.

DOI: 10.1007/s15010-022-01759-1