reports support the possibility of reinfection with P.1: • Naveka et al. describes the first confirmed case of reinfection with the P.1 lineage in a 29 year old female from Amazonas, Brazil, who was previously infected with a B.1 lineage virus.15 The patient (with no history of immunosuppression) was originally infected on March 16, 2020 with symptoms of myalgia, cough, sore throat, nausea, and back pain. After being exposed to a positive case on December 19, the patient exhibited the second symptomatic COVID-19 episode on December 27, 2020. Genomic sequencing confirmed that the infections were from two different SARS-CoV-2 lineages in each COVID-19 episode: a B.1 lineage in the initial infection and a P.1 lineage at reinfection. • A report from Brazil described a resurgence of COVID-19 cases in Manaus in January 2021, an area that had reported a high seroprevalence in October 2020 (adjusted seroprevalence of 76% (95% CI 67%-98%)).10 This suggests a possible increased risk of reinfection with the P.1 variant; however, other contributing factors for the resurgence may include antibody waning and higher transmissibility of the P.1 variant, in addition to immune evasion.10 COVID-19 P.1 Variant of Concern– What We Know So Far 5 References 1. Ontario Agency for Health Protection and Promotion (Public Health Ontario). COVID-19 UK variant VOC-202012/01– what we know so far [Internet]. Toronto, ON: Queen's Printer for Ontario; 2020 [cited 2021 Feb 03]. Available from: https://www.publichealthontario.ca/-/media/documents/ncov/covidwwksf/2020/12/what-we-know-uk-variant.pdf?la=en 2. Ontario Agency for Health Protection and Promotion (Public Health Ontario). COVID-19 B.1.351 (501Y.V2) variant of concern – what we know so far. Toronto, ON: Queen's Printer for Ontario; 2021. [cited 2021 Feb 14]. Available from: https://www.publichealthontario.ca/- /media/documents/ncov/covid-wwksf/2021/02/wwksf-covid-19-b1351501yv2-variant-ofconcern.pdf?la=en 3. Vasques Nonaka CK, Miranda Franco M, Gräf T, Almeida Mendes AV, Santana de Aguiar R, Giovanetti M, et al. Genomic evidence of a Sars-Cov-2 reinfection case with E484K spike mutation in Brazil. Preprints [Preprint]. 2021 Jan 26 [cited 2021 Feb 02]. Available fr Review of COVID-19 Variants and COVID-19 Vaccine Efficacy: What the Clinician Should Know? Deepa Vasireddya, f , Rachana Vanaparthyb, Gisha Mohanc , Srikrishna Varun Malayalad, Paavani Atlurie Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a beta coronavirus that belongs to the Coronaviridae family. SARSCoV-2 is an enveloped spherical-shaped virus. The ribonucleic acid (RNA) is oriented in a 5’-3’direction which makes it a positive sense RNA virus, and the RNA can be read directly as a messenger RNA. The nonstructural protein 14 (nsp14) has proofreading activity which allows the rate of mutations to stay low. A change in the genetic sequence is called a mutation. Genomes that differ from each other in genetic sequence are called variants. Variants are the result of mutations but differ from each other by one or more mutations. When a phenotypic difference is demonstrated among the variants, they are called strains. Viruses constantly change in two different ways, antigenic drift and antigenic shift. SARS-CoV-2 genome is also prone to various mutations that led to antigenic drift resulting in escape from immune recognition. The Center of Disease Control and Prevention (CDC) updates the variant strains in the different classes. The classes are variant of interest, variant of concern and variant of high consequence. The current variants included in the variant of interest by the USA are: B.1.526, B.1.525, and P.2; and those included in the variant of concern by the USA are B.1.1.7, P.1, B.1.351, B.1.427, and B.1.429. The double and triple mutant variants first reported in India have resulted in a massive increase in the number of cases. Emerging variants not only result in increased transmissibility, morbidity and mortality, but also have the ability to evade detection by existing or currently available diagnostic tests, which can potentially delay the diagnosis and treatment, exhibit decreased susceptibility to treatment including antivirals, monoclonal antibodies and convalescent plasma, possess the ability to cause reinfection in previously infected and recovered individuals, and vaccine breakthrough cases in fully vaccinated individuals. Hence, continuation of precautionary measures, genomic surveillance and vaccination plays an important role in the prevention of spread, early identification of variants, prevention of mutations and viral replication, respectively. Keywords: COVID-19; SARS-CoV-2; Variants; Vaccines; Mutations; Double mutant variant; Triple mutant variant; Vaccine breakthrough cases Introduction Natural origin and course Viruses innately have the ability to mutate constantly and lead to variants. Some variants emerge and disappear while some persist. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a beta coronavirus that belongs to the Coronaviridae family. The family is composed of single-stranded positive ribonucleic acid (RNA) viruses [1]. Coronaviruses have four genera, and the alpha and beta genera have viruses known to cause human disease. They are