Safety and immunogenicity of rAd26 and rAd5 vector-based heterologous prime-boost COVID-19 vaccine against SARS-CoV-2 in healthy adolescents: an open-label, non-randomized, multicenter, phase 1/2, dose-escalation study

To protect young individuals against SARS-CoV-2 infection, we conducted an open-label, prospective, non-randomised dose-escalation Phase 1/2 clinical trial to evaluate the immunogenicity and safety of the prime-boost “Sputnik V” vaccine administered at 1/10 and 1/5 doses to adolescents aged 12–17 years. The study began with the vaccination of the older cohort (15-to-17-year-old participants) with the lower (1/10) dose of vaccine and then expanded to the whole group (12-to-17-year-old participants). Next, 1/5 dose was used according to the same scheme. Both doses were well tolerated by all age groups. No serious or severe adverse events were detected. Most of the solicited adverse reactions were mild. No significant differences in total frequencies of adverse events were registered between low and high doses in age-pooled groups (69.6% versus 66.7%). In contrast, the 1/5 dose induced significantly higher humoral and T cell-mediated immune responses than the 1/10 dose. The 1/5 vaccine dose elicited higher antigen-binding (both S and RBD-specific) as well as virus-neutralising antibody titres at the maximum of response (day 42), also resulting in a statistically significant difference at a distanced timepoint (day 180) compared to the 1/10 vaccine dose. Higher dose resulted in increased cross-neutralization of Delta and Omicron variants.;Clinical Trial RegistrationClinicalTrials.gov, NCT04954092, LP-007632

Clonal diversity and clone formation in the parthenogenetic Caucasian rock Lizard Darevskia dahli [corrected].

The all-female Caucasian rock lizard species Darevskia dahli and other parthenogenetic species of this genus reproduce normally via true parthenogenesis. Previously, the genetic diversity of this species was analyzed using allozymes, mitochondrial DNA, and DNA fingerprint markers. In the present study, variation at three microsatellite loci was studied in 111 specimens of D. dahli from five populations from Armenia, and new information regarding clonal diversity and clone formation in D. dahli was obtained that suggests a multiple hybridization origin. All individuals but one were heterozygous at the loci studied. Based on specific allele combinations, 11 genotypes were identified among the individuals studied. Individuals with the same genotypes formed distinct clonal lineages: one major clone was represented by 72 individuals, an intermediate clone was represented by 21 individuals, and nine other clones were rare and represented by one or several individuals. A new approach based on the detection and comparison of genotype-specific markers formed by combinations of parental-specific markers was developed and used to identify at least three hybridization founder events that resulted in the initial formation of one major and two rare clones. All other clones, including the intermediate and seven rare clones, probably arose through postformation microsatellite mutations of the major clone. This approach can be used to identify hybridization founder events and to study clone formation in other unisexual taxa

Schematic representation of the SP network that reflects relationship between genotypes 1–9 in <i>D. dahli.</i>

<p>Complete sequences of <i>D. dahli</i> genotypes were analyzed using TCS software version 1.21. Genotypes 10 and 11 are plotted separately. Population distribution of the genotypes is shown by different colours. The black circles show, unsampled, but computer-predicted genotypes.</p

Clonal Diversity and Clone Formation in the Parthenogenetic Caucasian Rock Lizard <i>Darevskia dahlia</i>

<div><p>The all-female Caucasian rock lizard species <i>Darevskia dahli</i> and other parthenogenetic species of this genus reproduce normally via true parthenogenesis. Previously, the genetic diversity of this species was analyzed using allozymes, mitochondrial DNA, and DNA fingerprint markers. In the present study, variation at three microsatellite loci was studied in 111 specimens of <i>D. dahli</i> from five populations from Armenia, and new information regarding clonal diversity and clone formation in <i>D. dahli</i> was obtained that suggests a multiple hybridization origin. All individuals but one were heterozygous at the loci studied. Based on specific allele combinations, 11 genotypes were identified among the individuals studied. Individuals with the same genotypes formed distinct clonal lineages: one major clone was represented by 72 individuals, an intermediate clone was represented by 21 individuals, and nine other clones were rare and represented by one or several individuals. A new approach based on the detection and comparison of genotype-specific markers formed by combinations of parental-specific markers was developed and used to identify at least three hybridization founder events that resulted in the initial formation of one major and two rare clones. All other clones, including the intermediate and seven rare clones, probably arose through postformation microsatellite mutations of the major clone. This approach can be used to identify hybridization founder events and to study clone formation in other unisexual taxa.</p></div

Schematic representation of 11 genotypes formed by allelic combinations of microsatellite loci Du215, Du281, and Du323 in 111 <i>D. dahli</i> individuals.

<p>Parental-specific SNV markers are shown in square. Variable microsatellite clusters are shown in each of two alleles.</p

Allelic variations of microsatellite containing loci Du215, Du281, and Du323 in parthenogenetic <i>D. dahli</i> species.

1<p>Distances before (−) and after (+) microsatellite cluster are given in bp.</p

Sample size, combined genotype structure, diversity and distribution in the <i>D. dahli</i> populations.

<p>Pa – Papanino.</p><p>Ph – Phioletovo.</p><p>Va – Vaagni.</p><p>Dz – Dzoraget.</p><p>De – Dendropark.</p

Map of Armenia with the distribution of localities from which parthenogenetic <i>Darevskia dahli</i> populations were collected.

<p>Sampling localities are indicated by different colours. Papanino (+40° 42′ 27.76″, +44° 45′ 43.89″), Phioletovo (+40° 44′ 29.53″, +44° 39′ 31.25″), Vaagni (+40° 52′ 19.16″, +44° 31′ 28.60″), Dzoraget (+40° 54′ 15.02″, +44° 40′ 37.78″), Dendropark (+40° 59′ 30.55″, +44° 21′ 50.79″).</p

Sputnik V Effectiveness against Hospitalization with COVID-19 during Omicron Dominance

Mass vaccination campaigns against COVID-19 affected more than 90% of the population in most developed countries. The new epidemiologic wave of COVID-19 has been ongoing since the end of 2021. It is caused by a virus variant B.1.1.529, also known as &ldquo;Omicron&rdquo; and its descendants. The effectiveness of major vaccines against Omicron is not known. The purpose of this study is to evaluate the efficacy of the Sputnik V vaccine. The main goal is to assess its protection against hospitalization in the period of Omicron dominance. We conducted our study based on a large clinical center in Moscow (Russia) where 1112 patients were included. We used the case-population method to perform the calculations. The data we obtained indicate that the Omicron variant causes at least 90% of infections in the studied cohort. The effectiveness of protection against hospitalization with COVID-19 in our study was 85.9% (95% CI 83.0&ndash;88.0%) for those who received more than one dose. It was 87.6% (95% CI 85.4&ndash;89.5%) and 97.0% (95% CI 95.9&ndash;97.8%) for those who received more than two or three doses. The effectiveness in cases of more severe forms was higher than for less severe ones. Thus, present study indicates the high protective efficacy of vaccination against hospitalization with COVID-19 in case of Omicron lineage