Low Neutralizing Antibody Titers against the Mu Variant of SARS-CoV-2 in 31 BNT162b2 Vaccinated Individuals in Colombia

Abstract

Global surveillance programs for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are showing the emergence of variants with mutations in the spike protein. Genomic and laboratory surveillance are important to determine if these variants may be more infectious or less susceptible to antiviral treatments and vaccine-induced antibodies. Three of the most predominant SARS-CoV-2 variants in Colombia during the epidemiological peaks of 2021 were isolated: Mu, a variant of interest; Gamma, a variant of concern; B.1.111, which lacks genetic markers associated with greater virulence. Microneutralization assays were performed by incubating 120 mean tissue culture infectious doses (TCID50) of each SARS-CoV-2 isolate with five two-fold serial dilutions of sera from 31 BNT162b2-vaccinated volunteers. The mean neutralization titer (MN50) was calculated by the Reed–Muench method. At the end of August, Mu represented 49% of coronavirus disease 2019 (COVID-19) cases in Colombia, followed by 25% of Gamma. In contrast, B.1.111 became almost undetectable. The evaluation of neutralizing antibodies suggests that patients vaccinated with BNT162b2 generate neutralizing antibody titers against the Mu variant at significantly lower concentrations relative to B.1.111 and Gamma. This study shows the importance of continuing surveillance programs of emerging variants, as well as the need to evaluate the neutralizing antibody response induced by other vaccines.

Neutralizing responses in fully vaccinated with BNT162b2, CoronaVac, ChAdOx1, and Ad26.COV2.S against SARS-CoV-2 lineages in Colombia, 2020-2021

“…Several studies around the world evidenced a substantial fold decrease in the geometric mean nAb titer (GMT) against different VOCs/VOIs, relative to ancestral SARS-CoV-2 lineages in individuals with complete regimens of the vaccines currently approved or authorized in Colombia (2). Furthermore, studies on nAb responses in BNT162b2-vaccinated in Colombia evidenced a robust reduction in the neutralization of Mu, a VOI first detected in the Caribbean region of the country (9), by 75.7- and 17.7-fold, relative to B.1.111 and Gamma, respectively, which was comparable to reports from Asia and Europe (3). As these reductions in nAbs responses ranged from minimal up to total escape from vaccine nAbs depending on the SARS-CoV-2 variant and the population evaluated (2, 14), it is important to characterize the profile of vaccine nAbs in the context of the circulating SARS-CoV-2 variants in each country.…”

“…Studies in individuals vaccinated with BNT162b2 evidenced reduced nAb responses against pseudoviruses harboring the spike protein of the Mu variant, relative to four VOCs (Alpha, Beta, Gamma, and Delta) and two VOI (Epsilon and Lambda) (10). Furthermore, studies with infectious viruses also evidenced reduced nAb responses in BNT162b2 vaccinated patients (3).…”

“…Nasopharyngeal swab samples with positive RT-PCR for SARS-CoV-2, complete genome sequencing and PANGO lineage assignment B.1.111 (EPI_ISL_526971), P.1/Gamma (EPI_ISL_2500971), B.1.621/Mu (EPI_ISL_1821065) and AY.25.1/Delta (EPI_ISL_7314401), were selected for virus isolation and used for inoculation of Vero E6 monolayers as described previously (3). All assays with infectious SARS-CoV-2 viruses were performed in a biocontainment laboratory level 3.…”

“…The routine genomic surveillance of SARS-CoV-2 in Colombia allowed the identification of variants of interest (VOI) and concern (VOC) that co-circulate in the country with evidence of scape to neutralizing antibodies (nAb) generated by the BNT162b2 vaccine or natural infection (3, 4). The first two COVID-19 epidemic peaks in Colombia were dominated by B.1 non-VOC/VOI lineages (B.1.111, B.1.420, and B.1) and occurred from June to September 2020, and December 2020 to January 2021, respectively, while between April to August 2021, the third epidemic peak was dominated by Gamma (P.1) and Mu (B.1.621), representing 25% and 49% of the total cases (3). These two variants were gradually displaced by Delta lineages from July to December 2021.…”

Potential Antiviral Activity of Lactiplantibacillus plantarum KAU007 against Influenza Virus H1N1

“…Therefore, to provide frontline protection against influenza viruses, it is necessary to find alternative means of prevention regardless of strain specificity. Besides, there is a growing demand for unconventional measures to protect against the disease [ 5 , 8 , 9 ], and new variants of these viruses have become a global healthcare threat [ 10 , 11 , 12 ].…”