Project description:The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) variant BA.2.86 has over 30 mutations in spike compared with BA.2 and XBB.1.5, which raised the possibility that BA.2.86 might evade neutralizing antibodies (NAbs) induced by vaccination or infection. In this study, we show that NAb titers are substantially lower to BA.2.86 compared with BA.2 but are similar or slightly higher than to other current circulating variants, including XBB.1.5, EG.5.1, and FL.1.5.1. Moreover, NAb titers against all these variants were higher in vaccinated individuals with a history of XBB.1.5 infection compared with vaccinated individuals with no history of XBB.1.5 infection, suggesting the potential utility of the monovalent XBB.1.5 mRNA boosters.

| S-EPMC10842519 | biostudies-literature

Case Report: Omicron BA.2 Subvariant of SARS-CoV-2 Outcompetes BA.1 in Two Co-infection Cases.

Project description:Trends from around the world suggest that the omicron BA.2 subvariant is increasing in proportion to the original BA.1 subvariant. Here we report two cases of co-infection with omicron BA.1 and omicron BA.2 in co-exposed individuals. In both individuals, genome sequencing and/or S-gene specific PCR identified omicron BA.1 at early time-points, which was replaced by omicron BA.2 at later time-points of the infection. The timeline of our data supports the proposition that BA.2 outcompetes BA.1 in a real-life scenario, and in time becomes the dominant variant in the upper respiratory tract of the host.

| S-EPMC9041751 | biostudies-literature

Comparison of SARS-CoV-2 aerosol emission from patients with Omicron BA.1 or BA.2 subvariant infection.

Project description: Not available

| S-EPMC9158243 | biostudies-literature

Antigenic characterization of the SARS-CoV-2 Omicron subvariant BA.2.75.

Project description:The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron subvariant BA.2.75 emerged recently and appears to be spreading. It has nine mutations in spike compared with the currently circulating BA.2, raising concerns that it may further evade vaccine-elicited and therapeutic antibodies. We found BA.2.75 to be moderately more neutralization resistant to sera from vaccinated/boosted individuals than BA.2 (1.8-fold), similar to BA.2.12.1 (1.1-fold), but more neutralization sensitive than BA.4/5 (0.6-fold). Relative to BA.2, BA.2.75 showed heightened resistance to class 1 and class 3 monoclonal antibodies targeting the spike-receptor-binding domain while gaining sensitivity to class 2 antibodies. Resistance was largely conferred by G446S and R460K mutations. BA.2.75 was slightly resistant (3.7-fold) to bebtelovimab, a therapeutic antibody with potent activity against all Omicron subvariants. BA.2.75 also exhibited a higher binding affinity to host receptor ACE2 than other Omicron subvariants. BA.2.75 provides further insight into SARS-CoV-2 evolution as it gains transmissibility while incrementally evading antibody neutralization.

| S-EPMC9444898 | biostudies-literature

Effects of SARS-CoV-2 Alpha, Beta, and Delta variants, age, vaccination, and prior infection on infectiousness of SARS-CoV-2 infections.

Project description:In 2021, Qatar experienced considerable incidence of SARS-CoV-2 infection that was dominated sequentially by the Alpha, Beta, and Delta variants. Using the cycle threshold (Ct) value of an RT-qPCR-positive test to proxy the inverse of infectiousness, we investigated infectiousness of SARS-CoV-2 infections by variant, age, sex, vaccination status, prior infection status, and reason for testing in a random sample of 18,355 RT-qPCR-genotyped infections. Regression analyses were conducted to estimate associations with the Ct value of RT-qPCR-positive tests. Compared to Beta infections, Alpha and Delta infections demonstrated 2.56 higher Ct cycles (95% CI: 2.35-2.78), and 4.92 fewer cycles (95% CI: 4.67- 5.16), respectively. The Ct value declined gradually with age and was especially high for children <10 years of age, signifying lower infectiousness in small children. Children <10 years of age had 2.18 higher Ct cycles (95% CI: 1.88-2.48) than those 10-19 years of age. Compared to unvaccinated individuals, the Ct value was higher among individuals who had received one or two vaccine doses, but the Ct value decreased gradually with time since the second-dose vaccination. Ct value was 2.07 cycles higher (95% CI: 1.42-2.72) for those with a prior infection than those without prior infection. The Ct value was lowest among individuals tested because of symptoms and was highest among individuals tested as a travel requirement. Delta was substantially more infectious than Beta. Prior immunity, whether due to vaccination or prior infection, is associated with lower infectiousness of breakthrough infections, but infectiousness increases gradually with time since the second-dose vaccination.

| S-EPMC9513583 | biostudies-literature

Resistance of SARS-CoV-2 omicron subvariant BA.4.6 to antibody neutralisation.

Project description: Not available

| S-EPMC9621396 | biostudies-literature

SARS-CoV-2 Omicron subvariant BA.2.86: limited potential for global spread.

Project description: Not available

| S-EPMC10689828 | biostudies-literature