October 2020 in Nelson Mandela Bay in South Africa. By December 2020 it was also detected in Zambia. By April 1 2021, there were 323 reported cases in 31 jurisdictions in the USA. There are 23 mutations with 17 amino acid changes but the notable mutations in this variant are K417N, E484K, and N501Y on the S protein. It is suggested to have increased transmissibility and most commonly seen in young people without underlying diseases [22]. The mutation E484K in this variant mediates the antibody escape is the main reason for the reduced sensitivity to vaccines [25]. The mRNA vaccines (Pfizer and Moderna) were authorized in the USA before the identification of this strain in the country [26]. According to the latest studies, these two vaccines elicited lower neutralizing antibodies than that of the previous strains. Novavax, Janssen, and Astra-Zeneca conducted trials in South Africa that have dominant B.1.351 mutated strains. These studies demonstrated the lower vaccine efficacy compared to that of the other variants where this strain was not dominant [27]. Brazilian variant (P.1 or 20J/501Y.V3) P.1 variant also known as B.1.1.28.1 was first detected in North Brazil in the city of Manaus in the Amazonas state in December 2020. By January 2021, it was identified just outside Tokyo at Haneda airport among four travelers from Brazil during routine screening of passengers in samples analysed at National Institute of Infectious Diseases (NIID) in Japan. As of April 1, 2021, there were 224 reported cases in 22 jurisdictions in the USA [22]. It has 35 mutations with 17 amino acid changes. Its notable mutations are K417T, E484K, and N501Y [22]. In a study by Naveca et al, it was found that this variant is 2.2 times higher transmissible that led to a few cases of reinfection who recovered from COVID-19, and almost has a similar rate infection in the younger (18 - 59 years old) and older (> 60 years old) patients [28, 29]. B.1.351 and P.1 consist of similar receptor binding mutations and hence, the vaccine efficacy against P.1 strain is assumed to be similar to B.1.351. As the studies demonstrated reduced vaccine efficacy against B.1.351, it is likely that the efficacy against P. 1 strain is reduced [30]. Sinovac Biotech has initiated the clinical trials which demonstrated that the CoronoVac vaccine is 50% effective in preventing infection with the P.1 variant in Brazil [31]. Table 2. Overview of SARS-CoV-2 Variants [15] Signs and symptoms Original variant Variant of interest Variant of concern Variant of high consequence Symptoms Cough 28% 35% Fatigue/weakness 29% 32% Headache 30% 32% Muscle aches 21% 25% Sore throat 19% 22% Fever 20% 22% Loss of taste 19% 16% Loss of smell 19% 15% Disease transmissibility Yes No Yes Yes Disease severity Less Less More More Diagnostic testing failures No No No Yes Treatment Potential reduction in neutralization by monoclonal antibody treatments B.1.1.7 variants have minimal, while P.1, B.1.351 variants have moderate and B.1.427, B.1.429 have significant impact on EUA therapeutics and monoclonal antibody treatments, respectively. Vaccine effectiveness Pfizer, Moderna, and Janssen are effective Potential reduction in neutralization by post-vaccination sera Minimal impact on neutralization by post vaccination sera for B.1.1.7 variant, while other variants have moderate reduction in neutralization by post-vaccination sera. Significant impact on neutralization by post vaccination sera Notification to WHO and CDC No No Yes Yes WHO: World Health Organisation; CDC: Center of Disease Control and Prevention; EUA: Emergency Use Authorization. Articles © The authors | Journal compilation © J Clin Med Res and Elmer Press Inc™ | www.jocmr.org 321 Vasireddy et al J Clin Med Res. 2021;13(6):317-325 Brazilian variant (B.1.1.28) The Brazilian variant B.1.1.28 was initially found in the state of Rio de Janeiro in Brazil, and is the P2 lineage. Unlike P.1 variant, B.1.1.28 variant has only one notable E484K mutation in the S protein [32]. The therapeutic and vaccine efficacy has not been reported yet. Similar to B.1.351 and P.1 variants, the vaccine might be ineffective against this variant [33]. US Midwest variant (20C-US or COH.20G/501Y) It was detected in Ohio followed by other Midwest states in December 2020 and January 2021. This variant has mutations on the S protein (Q677H), M protein (A85S) and on the N protein (D377Y). Another variant with the mutation S N501Y, a marker of the B.1.1.7, with no other associated mutations with that strain has been identified [34]. Currently there is not any evidence of increased transmissibility or virulence for this variant. US San Francisco Bay Area variant (B.1.427 and B.1.429) These variants were first identified in California in February, 2021. The notable mutations in B.1.427 are L452R and D614G; while mutations in B.1.429 are S131, W152C, L452R and D614G. Both variants have 20% increased risk of transmissibility and reduction in therapeutic efficacy [15]. It was identified last year across the USA and Europe. It is a variant with a mutation in the S protein. In January 2021 it rose rapidly as the cause of cases across several counties in California [35]. US Southern California variant (CAL.20C) It was first seen in July 2020 in Southern California and detected again amongst population samples of the same region in October 2020. Its notable mutations are ORF1a: I4205V, ORF1b: D1183Y, S: S13I; W152C