Reliably Assessing Duration of Protection for COVID-19 Vaccines

Decision-making about booster dosing for COVID-19 vaccine recipients hinges on reliable methods for evaluating the longevity of vaccine protection. We show that modeling of protection as a piecewise linear function of time since vaccination for the log hazard ratio of the vaccine effect provides more reliable estimates of vaccine effectiveness at the end of an observation period and also more reliably detects plateaus in protective effectiveness as compared with the traditional method of estimating a constant vaccine effect over each time period. This approach will be useful for analyzing data pertaining to COVID-19 vaccines and other vaccines where rapid and reliable understanding of vaccine effectiveness over time is desired.

Effectiveness of complete primary vaccination against COVID-19 at primary care and community level during predominant Delta circulation in Europe: multicentre study analysis by age-group, vaccine brand and time since vaccination, I-MOVE-COVID-19 and ECDC networks, July–August 2021

IntroductionIn July and August 2021, the SARS-CoV-2 Delta variant dominated in Europe. We measured COVID-19 vaccine effectiveness (VE) against symptomatic infection, using a multicentre test-negative study at primary care/community level in Europe.MethodsPatients presenting with COVID-19/ARI symptoms at primary care/community level in 10 countries were tested for SARS-CoV-2. We measured complete primary course overall VE among those aged 30–44, 45–59, 60–74 and ≥75 years, and among those 30–59 and ≥60 years by vaccine brand and by time since vaccination.ResultsOverall VE was 74% (95%CI: 69–79), 76% (95%CI: 71–80), 63% (95%CI: 48–75), 63% (95%CI: 16–83) among those aged 30–44, 45–59, 60–74 and ≥75 years, respectively. VE among those aged 30–59 years was 78% (95%CI: 75–81), 66% (95%CI: 58–73), 91% (95%CI: 87–94) and 52% (95%CI: 40–61), for Comirnaty, Vaxzevria, Spikevax and COVID-19 Vaccine Janssen, respectively. VE among those aged ≥60 years was 67% (95%CI: 52–77), 65% (95%CI: 48–76), 83% (95%CI: 64–92) for Comirnaty, Vaxzevria and Spikevax, respectively. Comirnaty VE among those aged 30–59 years was 87% (95%CI: 83–89) and 65% (95%CI: 56–71%) at 14–29 days and ≥90 days between vaccination and onset of symptoms, respectively.ConclusionsVE against the symptomatic SARS-CoV-2 Delta variant infection varied among brands, ranging from 52–91%. While some waning of the vaccine effect may be present (sample size limited this analysis to only Comirnaty), protection was 65% ≥90 days between vaccination and onset.

SARS-CoV-2 mechanistic correlates of protection: insight from modelling response to vaccines

The definition of correlates of protection is critical for the development of next generation SARS-CoV-2 vaccine platforms. Here, we propose a new framework for identifying mechanistic correlates of protection based on mathematical modelling of viral dynamics and data mining of immunological markers. The application to three different studies in non-human primates evaluating SARS-CoV-2 vaccines based on CD40-targeting, two-component spike nanoparticle and mRNA 1273 identifies and quantifies two main mechanisms that are a decrease of rate of cell infection and an increase in clearance of infected cells. Inhibition of RBD binding to ACE2 appears to be a robust mechanistic correlate of protection across the three vaccine platforms although not capturing the whole biological vaccine effect. The model shows that RBD/ACE2 binding inhibition represents a strong mechanism of protection which required significant reduction in blocking potency to effectively compromise the control of viral replication.

Plasmonic gold nanostars for synergistic photoimmunotherapy to treat cancer

Cancer is the second leading cause of death and there is an urgent need to improve cancer management. We have developed an innovative cancer therapy named Synergistic Immuno Photothermal Nanotherapy (SYMPHONY) by combining gold nanostars (GNS)-mediated photothermal ablation with checkpoint inhibitor immunotherapy. Our previous studies have demonstrated that SYMPHONY photoimmunotherapy not only treats the primary tumor but also dramatically amplifies anticancer immune responses in synergy with checkpoint blockade immunotherapy to treat remote and unresectable cancer metastasis. The SYMPHONY treatment also induces a ‘cancer vaccine’ effect leading to immunologic memory and prevents cancer recurrence in murine animal models. This manuscript provides an overview of our research activities on the SYMPHONY therapy with plasmonic GNS for cancer treatment.

Levels of Produced Antibodies after Vaccination with mRNA Vaccine; Effect of Previous Infection with SARS-CoV-2

The aim of this study was to estimate the immunogenic effect of mRNA vaccine against SARS-CoV-2. This study included 510 participants who received mRNA vaccine. The measurement of anti-COVID-19 antibodies was performed using the Abbott SARS-CoV-2 IgG quantitative assay (Abbott). Overall, mean titer of anti-Spike antibodies was 19,319.2 ± 1787.5 AU/mL. Vaccination induced a robust immunogenic response in those previously infected with SARS-CoV-2 compared with non-infected subjects. Additionally, individuals that were asymptomatic after vaccination produced lower levels of antibodies compared to feverish individuals. In conclusion, remarkably high levels of anti-Spike COVID-19 antibodies were observed after vaccination.