Risultati per: L’eparina inibisce la proteina spike del virus SARS-Cov-2

Annals of Internal Medicine, Volume 176, Issue 12, December 2023.

Annals of Internal Medicine, Volume 176, Issue 12, December 2023.

New results suggest that a live-virus vaccine intended to protect against shingles—a condition caused by reactivation of the varicella-zoster virus, which also causes chickenpox—prevented illness in 67% of people in the first year after vaccination. But after 10 years, the vaccine’s efficacy against shingles, also known as herpes zoster, had declined to 15%. The study used electronic health record data from more than 500 000 adults aged 50 years or older who received the shot between 2007 and 2018 in California.

Rafforzare le vaccinazioni e la capacità ospedaliera

New England Journal of Medicine, Volume 389, Issue 24, Page 2276-2276, December 2023.

New England Journal of Medicine, Volume 389, Issue 24, Page 2299-2301, December 2023.

Oltre mille i casi in Europa, secondo anno record dopo il 2018

Annals of Internal Medicine, Ahead of Print.

Annals of Internal Medicine, Ahead of Print.

Objectives
The study aim was to evaluate vaccine effectiveness (VE) of COVID-19 vaccines in preventing symptomatic COVID-19 among healthcare workers (HCWs) in Zambia. We sought to answer the question, ‘What is the vaccine effectiveness of a complete schedule of the SARS-CoV-2 vaccine in preventing symptomatic COVID-19 among HCWs in Zambia?’

Design/setting
We conducted a test-negative case–control study among HCWs across different levels of health facilities in Zambia offering point of care testing for COVID-19 from May 2021 to March 2022.

Participants
1767 participants entered the study and completed it. Cases were HCWs with laboratory-confirmed SARS-CoV-2 and controls were HCWs who tested SARS-CoV-2 negative. Consented HCWs with documented history of vaccination for COVID-19 (vaccinated HCWs only) were included in the study. HCWs with unknown test results and unknown vaccination status, were excluded.

Primary and secondary outcome measures
The primary outcome was VE among symptomatic HCWs. Secondary outcomes were VE by: SARS-CoV-2 variant strains based on the predominant variant circulating in Zambia (Delta during May 2021 to November 2021 and Omicron during December 2021 to March 2022), duration since vaccination and vaccine product.

Results
We recruited 1145 symptomatic HCWs. The median age was 30 years (IQR: 26–38) and 789 (68.9%) were women. Two hundred and eighty-two (24.6%) were fully vaccinated. The median time to full vaccination was 102 days (IQR: 56–144). VE against symptomatic SARS-CoV-2 infection was 72.7% (95% CI: 61.9% to 80.7%) for fully vaccinated participants. VE was 79.4% (95% CI: 58.2% to 90.7%) during the Delta period and 37.5% (95% CI: –7.0% to 63.3%) during the Omicron period.

Conclusions
COVID-19 vaccines were effective in reducing symptomatic SARS-CoV-2 among Zambian HCWs when the Delta variant was circulating but not when Omicron was circulating. This could be related to immune evasive characteristics and/or waning immunity. These findings support accelerating COVID-19 booster dosing with bivalent vaccines as part of the vaccination programme to reduce COVID-19 in Zambia.

Purpose
The RESPIRA cohort aims to describe the nature, magnitude, time course and efficacy of the immune response to SARS-CoV-2 infection and vaccination, population prevalence, and household transmission of COVID-19.

Participants
From November 2020, we selected age-stratified random samples of COVID-19 cases from Costa Rica confirmed by PCR. For each case, two population-based controls, matched on age, sex and census tract were recruited, supplemented with hospitalised cases and household contacts. Participants were interviewed and blood and saliva collected for antibodies and PCR tests. Participants will be followed for 2 years to assess antibody response and infection incidence.

Findings to date
Recruitment included 3860 individuals: 1150 COVID-19 cases, 1999 population controls and 719 household contacts from 304 index cases. The age and regional distribution of cases was as planned, including four age strata, 30% rural and 70% urban. The control cohort had similar sex, age and regional distribution as the cases according to the study design. Among the 1999 controls recruited, 6.8% reported at enrolment having had COVID-19 and an additional 12.5% had antibodies against SARS-CoV-2. Compliance with visits and specimens has been close to 70% during the first 18 months of follow-up. During the study, national vaccination was implemented and nearly 90% of our cohort participants were vaccinated during follow-up.

Future plans
RESPIRA will enable multiple analyses, including population prevalence of infection, clinical, behavioural, immunological and genetic risk factors for SARS-CoV-2 acquisition and severity, and determinants of household transmission. We are conducting retrospective and prospective assessment of antibody levels, their determinants and their protective efficacy after infection and vaccination, the impact of long-COVID and a series of ancillary studies. Follow-up continues with bimonthly saliva collection for PCR testing and biannual blood collection for immune response analyses. Follow-up will be completed in early 2024.

Trial registration number
NCT04537338.

The first study to investigate potential associations between gut microbiota composition and SARS-CoV-2 vaccine immunogenicity was recently published in Gut.1 This study demonstrated a statistically significant reduction in alpha diversity and a shift in gut microbiota composition following BNT162b2 vaccination, characterised by reductions in Actinobacteriota, Blautia, Dorea, Adlercreutzia, Asacchaobacter, Coprococcus, Streptococcus, Collinsella and Ruminococcus spp and an increase in Bacteroides cacaae and Alistipes shahii. Our prospective observational study (n=52; figure 1A, ) similarly showed a shift in gut microbiota after the first BNT162b2 vaccine dose (p=0.016; ), including a reduction in Actinobacteria, Blautia spp (p

SARS-CoV-2 binds to ACE2 receptors and enters cells. The symptoms are cough, breathlessness, loss of taste/smell and X-ray evidence of infiltrates on chest imaging initially caused by oedema, and subsequently by a lymphocytic pneumonitis. Coagulopathy, thrombosis and hypotension occur. Worse disease occurs with age, obesity, ischaemic heart disease, hypertension and diabetes.
These features may be due to abnormal activation of the contact system. This triggers coagulation and the kallikrein-kinin system, leading to accumulation of bradykinin and its derivatives, which act on receptors B1R and B2R. Receptor activation causes cough, hypotension, oedema and release of the cytokine interleukin-6 (IL-6) which recruits lymphocytes. These effects are core features seen in early SARS CoV-2 infection.
Methods and analysis
In this study, hypoxic patients with COVID-19 with symptom onset ≤7 days will be randomised to either a bradykinin inhibitor (icatibant) or placebo. Patients and investigators will be blinded. The primary outcome will be blood oxygenation, measured by arterial blood sampling. The secondary outcome will be cardiovascular status. Retinal imaging will be performed to assess vessel size. Blood samples will be taken for measurement of inflammatory analyses including IL-6. As a separate substudy, we will also take comparator blood inflammatory samples from a COVID-19-negative cohort.

Ethics and dissemination
The study has received the following approvals: West Midlands–Edgbaston Research Ethics Committee. Medicines and Healthcare products Regulatory Agency has issued a clinical trial authorisation. Belfast Health and Social Care Trust is the study sponsor. Results will be made available to participants upon request and findings will be presented and published.

Trial registration number
NCT05407597

Objectives
The coronavirus is continuously mutating and creating new SARS-CoV-2 variants. Public awareness about SARS-CoV-2 mutation is essential for effective preventive measures. The present study aimed to assess the knowledge, attitude and practices (KAP) towards SARS-CoV-2 variants among the general population in Bangladesh.

Design
We conducted this online survey between 9 April 2021 and 10 May 2021 using structured questionnaires to collect the information.

Setting
We distributed the survey link among the participants from all 64 districts of Bangladesh using social media platforms.

Participants
A total of 1,090 respondents completed this survey. After careful evaluation, we excluded 18 responses due to partial or incomplete information, and 1,072 responses entered into the final analysis.

Primary outcome
The KAP of participants towards SARS-CoV-2 variants depends on their demographic backgrounds. Associations between demographic characteristics and the likelihood of having adequate KAP were estimated using adjusted logistic regressions.

Results
Among the participants, 42% had a poor knowledge level, 4% had a low attitude level and 14% had a poor practice score. The average knowledge, attitude and practice score were 2.65, 4.194 and 4.464 on a scale of 5, respectively. Only 51.8% of the participants knew about mutant strains, and only 47.6% knew about the effectiveness of vaccines against new variants. The key factors associated with poor knowledge levels were educational levels, area of residence, geographic location, and concern regarding COVID-19. Sociodemographic factors for poor attitude levels were geographic location, vaccination and concern regarding COVID-19. The pivotal factors in determining poor practice scores were the residence area of people and concern regarding COVID-19.

Conclusions
The knowledge level and positive attitude are associated with better preventive measures against SARS-CoV-2 variants. Based on these findings, we recommended several awareness programmes on SARS-CoV-2 mutations and variants for the rural population in Bangladesh to increase overall awareness levels.

New England Journal of Medicine, Volume 389, Issue 22, Page 2105-2107, November 2023.

To the Editor A recent Research Letter examined COVID-19 treatment rates in US nursing homes from May 31, 2021, through December 25, 2022, and found that only 1 in 4 nursing home residents with COVID-19 had been treated with antiviral treatments and that more than 40% of nursing homes reported never administering any oral antiviral or monoclonal antibody treatment in the 19-month study window. As a practicing nursing home attending physician and medical director, I wish to elaborate on some of the barriers to treatment in nursing homes to highlight policy changes that could improve treatment rates in future pandemics.