Highlights HIV-1 and SARS-CoV-2 are likely to exhibit a synergic effect on immunity in serious cases of HIV/SARS-CoV-2 co-infection. Exhausted T lymphocyte dynamics along with IL-10 and TGFβ growth during COVID-19 course may be an effective prognostic marker of this synergy as well as overall prognosis of the co-infection disease. HIV without antiretroviral therapy may be a dangerous comorbidity of COVID-19. Conversely, COVID-19 clinical course and immune status of HIV patients with a proper ART did not differ significantly from the control group of SARS-CoV-2 positive people without HIV. SARS-CoV-2 was detected to exasperate a loss of lymphocytic cytokine-producing ability with respect to IL-2, TNFα and IFNγ.

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The total vaccination rate remains relatively low in Russia as of March 2022 (around 55%, with around 20% in some regions). In the paper, we study the reasons for it. We communicate the results of our survey aimed at detecting reasons for the relatively low anti-SARS-CoV-2 vaccination rate in Russia (47.1% as of mid-January 2022) and suggest potential measures to increase the level of confidence in the Russian vaccination campaign. A total of 14,310 users exhibited interest to participate in the research (16.84% of the total number of invitations sent in the Russian social network VKontakte). After the sample set repair, only 5822 (40.68% of those who agreed to participate) responses were suitable for the research, and they composed the final set. The age range of the respondents was 16–51 years old (y.o.) with a mean of 29.1 ± 10.6 y.o. The proportion of the female gender in responses was 44.23%. A total of 2454 persons (42.15%) expressed their hesitant, cautious, or negative attitude towards vaccine uptake. Of the 2454 persons with cautious attitude towards vaccination, only 928 (37.82%) were concerned about the quality of the Russian vaccines. A total of 1323 individuals (53.91%) supported one or more conspiracy beliefs. A total of 5064 (86.98% of the whole set) showed cautious or negative attitude towards the planned introduction of a nationwide system of vaccination certification/verification based on QR codes. The main social factors that hinder the Russian vaccination campaign are: vexation over the lack of desire of officials to receive feedback from the general population regarding vaccination, wide support for conspiracy beliefs, and controversy over the QR code-based digital system. To elevate the vaccination rate in Russia, the following steps may be taken: social encouragement of those who support vaccination, increase in transparency of the vaccination campaign, acceptance of both digital and paper vaccination certificates, increase in participation of society in vaccination-related discussions, public disclosure of vaccine composition, and avoidance of excessive digitalization of data in the vaccination campaign.

Highlights SIR compartmental model of COVID-19 spread may help to evaluate efficiency of lockdown measures. Epidemiological data collected in fifteen european countries, are taken as input parameters. Herd immunity level and the time of its formation are considered as factors indicating efficiency of lockdowns. Lockdown and no-lockdown mode of containment lead to roughly similar results. Lockdowns do not stop COVID-19 spread. Rationale for lockdowns is avoidance of healthcare system overburdening. Reliance on lockdowns as the only administrative measures that may contain a pandemic, is a misstep that should be avoided in the future.

The effect of nitrogen dioxide (NO 2 ) adsorption on free charge carriers and spin centers in porous silicon has been studied by FTIR and ESR spectroscopy. The silicon dangling bond (P b1 -center) density rises with increasing NO 2 pressure ( 2 NO P ) while free charge carrier concentration depends on 2 NO P nonmonotonically. The experimental results are explained by a microscopic model taking into account both the formation of P b1 + − (NO 2 ) − donor-acceptor pairs and NO 2 -induced oxidation of Si nanocrystal surfaces.