Vaccine effectiveness of primary and booster COVID-19 vaccinations against SARS-CoV-2 infection in the Netherlands from 12 July 2021 to 6 June 2022: a prospective cohort study

BBIBP-CorV vaccine effectiveness against COVID-19 in patients aged 60 years and older during the Delta-dominant period in the Federation of Bosnia and Herzegovina, a test-negative case-control study

COVID-19 vaccine uptake in the Federation of Bosnia and Herzegovina (FBiH) accelerated in the second half of 2021, with greater vaccine availability. In this study, we estimated the vaccine effectiveness (VE) of complete primary series BBIBP-CorV vaccine against COVID-19 in patients aged 60 years and older, during the Delta-dominant period, using a test-negative case-control design. Surveillance sites were 11 primary health care centers (PHC) collecting patient data from October 1, 2021, to January 4, 2022, retrospectively according to a common protocol. In total, we included 1711 participants in the analysis: 933 cases and 778 controls. Of the 933 cases, 508 (54.4 %) had mild and 425 (45.6 %) had moderate to severe disease presentation. We observed no effectiveness against mild COVID-19. Overall vaccine effectiveness was 65.0 % (95 %CI: 40.1-79.5) against moderate to severe COVID-19. In time since vaccination analysis, VE was 78.7 % (95 % CI: 54.8-89.9) in patients who received their last dose < 90 days before onset; 66.0 % (95 % CI: -0.5-88.5) in those 90-119 days before onset; 42.1 % (95 % CI: -88.6-82.3) in those 120-149 days before onset and 45.0 % (95 % CI: -94.0-84.4) in those ≥ 150 days before onset. In our study, two doses of BBIBP-CorV provided considerable protection against moderate to severe COVID-19 in older adults, highest within 3 months after second dose, during the Delta-dominant period. Point estimates declined thereafter, suggesting a need for additional doses.

Evaluation of Strategies for Transitioning to Annual SARS-CoV-2 Vaccination Campaigns in the United States

BACKGROUND

The U.S. Food and Drug Administration has proposed administering annual SARS-CoV-2 vaccines.

OBJECTIVE

To evaluate the effectiveness of an annual SARS-CoV-2 vaccination campaign, quantify the health and economic benefits of a second dose provided to children younger than 2 years and adults aged 50 years or older, and optimize the timing of a second dose.

DESIGN

An age-structured dynamic transmission model.

SETTING

United States.

PARTICIPANTS

A synthetic population reflecting demographics and contact patterns in the United States.

INTERVENTION

Vaccination against SARS-CoV-2 with age-specific uptake similar to that of influenza vaccination.

MEASUREMENTS

Incidence, hospitalizations, deaths, and direct health care cost.

RESULTS

The optimal timing between the first and second dose delivered to children younger than 2 years and adults aged 50 years or older in an annual vaccination campaign was estimated to be 5 months. In direct comparison with a single-dose campaign, a second booster dose results in 123 869 fewer hospitalizations (95% uncertainty interval [UI], 121 994 to 125 742 fewer hospitalizations) and 5524 fewer deaths (95% UI, 5434 to 5613 fewer deaths), averting $3.63 billion (95% UI, $3.57 billion to $3.69 billion) in costs over a single year.

LIMITATIONS

Population immunity is subject to degrees of immune evasion for emerging SARS-CoV-2 variants. The model was implemented in the absence of nonpharmaceutical interventions and preexisting vaccine-acquired immunity.

CONCLUSION

The direct health care costs of SARS-CoV-2, particularly among adults aged 50 years or older, would be substantially reduced by administering a second dose 5 months after the initial dose.

PRIMARY FUNDING SOURCE

Natural Sciences and Engineering Research Council of Canada, Notsew Orm Sands Foundation, National Institutes of Health, Centers for Disease Control and Prevention, and National Science Foundation.

Effectiveness of Omicron XBB.1.5 vaccine against infection with SARS-CoV-2 Omicron XBB and JN.1 variants, prospective cohort study, the Netherlands, October 2023 to January 2024

We estimated vaccine effectiveness (VE) of SARS-CoV-2 Omicron XBB.1.5 vaccination against self-reported infection between 9 October 2023 and 9 January 2024 in 23,895 XBB.1.5 vaccine-eligible adults who had previously received at least one booster. VE was 41% (95% CI: 23-55) in 18-59-year-olds and 50% (95% CI: 44-56) in 60-85-year-olds. Sequencing data suggest lower protection against the BA.2.86 (including JN.1) variant from recent prior infection (OR = 2.8; 95% CI:1.2-6.5) and, not statistically significant, from XBB.1.5 vaccination (OR = 1.5; 95% CI:0.8-2.6).

Olgotrelvir, a dual inhibitor of SARS-CoV-2 Mpro and cathepsin L, as a standalone antiviral oral intervention candidate for COVID-19

BACKGROUND

Oral antiviral drugs with improved antiviral potency and safety are needed to address current challenges in clinical practice for treatment of COVID-19, including the risks of rebound, drug-drug interactions, and emerging resistance.

METHODS

Olgotrelvir (STI-1558) is designed as a next-generation antiviral targeting the SARS-CoV-2 main protease (Mpro), an essential enzyme for SARS-CoV-2 replication, and human cathepsin L (CTSL), a key enzyme for SARS-CoV-2 entry into host cells.

FINDINGS

Olgotrelvir is a highly bioavailable oral prodrug that is converted in plasma to its active form, AC1115. The dual mechanism of action of olgotrelvir and AC1115 was confirmed by enzyme activity inhibition assays and co-crystal structures of AC1115 with SARS-CoV-2 Mpro and human CTSL. AC1115 displayed antiviral activity by inhibiting replication of all tested SARS-CoV-2 variants in cell culture systems. Olgotrelvir also inhibited viral entry into cells using SARS-CoV-2 Spike-mediated pseudotypes by inhibition of host CTSL. In the K18-hACE2 transgenic mouse model of SARS-CoV-2-mediated disease, olgotrelvir significantly reduced the virus load in the lungs, prevented body weight loss, and reduced cytokine release and lung pathologies. Olgotrelvir demonstrated potent activity against the nirmatrelvir-resistant Mpro E166 mutants. Olgotrelvir showed enhanced oral bioavailability in animal models and in humans with significant plasma exposure without ritonavir. In phase I studies (ClinicalTrials.gov: NCT05364840 and NCT05523739), olgotrelvir demonstrated a favorable safety profile and antiviral activity.

CONCLUSIONS

Olgotrelvir is an oral inhibitor targeting Mpro and CTSL with high antiviral activity and plasma exposure and is a standalone treatment candidate for COVID-19.

FUNDING

Funded by Sorrento Therapeutics.

Vaccine Effectiveness Against Severe Acute Respiratory Syndrome Coronavirus 2 Delta and Omicron Infection and Infectiousness Within Households in the Netherlands Between July 2021 and August 2022

BACKGROUND

We aimed to estimate vaccine effectiveness against infection (VE-infection) and against further transmission (VE-infectiousness) in a household setting during Delta and Omicron. Knowing these effects can aid policy makers in deciding which groups to prioritize for vaccination.

METHODS

Participants with a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) test were asked about coronavirus disease 2019 (COVID-19) vaccination status and SARS-CoV-2 testing of their household members 1 month later. VE-infection and VE-infectiousness were estimated using generalized estimating equation logistic regression adjusting for age, vaccination status, calendar week, and household size.

RESULTS

A total of 3399 questionnaires concerning 4105 household members were included. During the Delta period, VE-infection and VE-infectiousness of primary series were 47% (95% confidence interval [CI], -27% to 78%) and 70% (95% CI, 28% to 87%), respectively. During the Omicron period, VE-infection was -36% (95% CI, -88% to 1%) for primary series and -28% (95% CI, -77% to 7%) for booster vaccination. VE-infectiousness was 45% (95% CI, -14% to 74%) for primary series and 64% (95% CI, 31% to 82%) for booster vaccination.

CONCLUSIONS

Our study shows that COVID-19 vaccination is effective against infection with SARS-CoV-2 Delta and against infectiousness of SARS-CoV-2 Delta and Omicron. Estimation of VE against infection with SARS-CoV-2 Omicron was limited by several factors. Our results support booster vaccination for those in close contact with vulnerable people to prevent transmission.

SARS-CoV-2 Infection in Cities from the Southern Region of Bahia State, Brazil: Analysis of Variables Associated in Both Individual and Community Level

The COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), challenged public health systems worldwide. Individuals in low-income countries/regions are still at individual and community risk concerning inequality, sanitation, and economic conditions. Besides, during the pandemic, the transmission in municipalities and communities in the countryside and less developed regions kept viral spread and required structured and strengthened clinical and laboratory surveillance. Here, we present an observational, analytic, cross-sectional study conducted using secondary data from the Laboratório de Farmacogenômica e Epidemiologia Molecular (LAFEM)-Universidade Estadual de Santa Cruz (UESC), to evaluate individual and community factors associated to SARS-CoV-2 infection in outpatients from different cities from Southern Region of Bahia State, in Brazil. The data were collected between June 2021 and May 2022. The SARS-CoV-2 positivity by RT-qPCR was correlated with low socio-economic indicators, including the Human development index (HDI_c) and Average worker salary (AWSc). Besides, in general, females were less likely to test positive for SARS-CoV-2 (OR = 0.752; CI 95% 0.663-0.853; p < 0.0001), while brown individuals had more positivity for infection (p < 0.0001). In addition, those who had clinical symptoms were more likely to test positive for SARS-CoV-2 (OR = 6.000; CI 95% 4.932-7.299; p < 0.0001). Although dry cough, headache, and fever were the most frequent, loss of taste (OR = 5.574; CI 95% 4.334-7.186) and loss of smell (OR = 6.327; CI 95% 4.899-8.144) presented higher odds ratio to be positive to SARS-CoV-2 by RT-qPCR. Nonetheless, the distribution of these characteristics was not homogenous among the different cities, especially for age and gender. The dynamic of SARS-CoV-2 positivity differed between cities and the total population and reinforces the hypothesis that control strategies for prevention needed to be developed based on both individual and community risk levels to mitigate harm to individuals and the health system.

Effectiveness of Oral Nirmatrelvir/Ritonavir vs. Intravenous Three-Day Remdesivir in Preventing Progression to Severe COVID-19: A Single-Center, Prospective, Comparative, Real-Life Study

BACKGROUND

Nirmatrelvir/ritonavir (NMV/r) and three-day course remdesivir (3RDV) have been approved as early treatments for COVID-19 outpatients not requiring supplemental oxygen. Real-life data on the efficacy of antivirals among immunocompromised patients or directly comparing their effectiveness in preventing hospitalization and/or death are scarce.

METHODS

Prospective, observational study conducted in a tertiary care hospital, from 1 January 2022 until 15 March 2023, during the prevalence of the Omicron variant. Inverse probability of treatment weighting (IPTW) was used to account for differences between treatment groups.

RESULTS

We included 521, mainly immunocompromised (56%), patients in our analysis; 356 (68.3%) received 3RDV and 165 (31.7%) NMV/r. Overall, 15/521 (2.9%) patients met the primary end-point of hospitalization at 30 days (3RDV arm: 10/356, 2.8% vs. NMV/r arm: 5/165, 3%, p = 1). On IPTW-adjusted univariable analysis, the choice of treatment did not affect outcomes. In multivariable logistic regression analysis, we found that one (OR 0.26, 95%CI 0.07-0.99, p = 0.049) or two (OR 0.06, 95%CI 0.01-0.55, p = 0.014) vaccine booster shots reduced the risk for adverse outcomes.

CONCLUSION

In our patient population of high-risk, mainly immunocompromised, vaccinated patients during the prevalence of the Omicron variant, NMV/r and 3RDV were equally effective early treatments for the prevention of hospitalization and/or death.