Safety Surveillance of COVID-19 mRNA Vaccines Through the Vaccine Safety Datalink

Risk of myocarditis after three doses of COVID-19 mRNA vaccines in the United States, 2020-2022: A self-controlled case series study

AIM

Myocarditis is a recognized safety concern following COVID-19 mRNA vaccination. However, there is limited research quantifying the risk associated with the third dose or comparing the risk between the three doses. The US Vaccine Adverse Event Reporting System (VAERS) is a passive surveillance system that monitors rare adverse events after US-licensed vaccination. However, studies analyzing VAERS data have often faced criticism for underreporting cases and lacking a control group to assess the increase in baseline risk.

METHODS

The temporal association between myocarditis onset and COVID-19 vaccination was studied. To overcome limitations, a novel modified self-controlled case series method was employed, explicitly modeling the case reporting process in VAERS data.

RESULTS

We found an increased risk of myocarditis during the 1- to 3-day period following the second and third doses of both the BNT162b2 vaccine and the mRNA-1273 vaccine. Following the second dose, the relative incidence (RI) was 4.89 (95% confidence interval (CI), 2.39-10.08) for the BNT162b2 vaccine and 2.86 (95% CI: 1.18-7.03) for the mRNA-1273 vaccine. Similarly, following the third dose, the RI was 9.04 (95% CI: 2.79-40.99) for the BNT162b2 vaccine and 4.71 (95% CI: 1.42-19.09) for the mRNA-1273 vaccine. No significant increase in risk was observed during other periods. Notably, our analysis also identified a similar increased risk of myocarditis among individuals aged below 30.

CONCLUSIONS

These findings raise safety concerns regarding COVID-19 mRNA vaccines, provide insights into the quantification of myocarditis risk at different postvaccination periods, and offer a novel approach to interpreting passive surveillance system data.

COVID-19 Vaccine Safety Surveillance in Early Pregnancy in the United States: Design Factors Affecting the Association Between Vaccine and Spontaneous Abortion

In the Vaccine Safety Datalink (VSD), we previously reported no association between coronavirus disease 2019 (COVID-19) vaccination in early pregnancy and spontaneous abortion (SAB). The present study aims to understand how time since vaccine rollout or other methodological factors could affect results. Using a case-control design and generalized estimating equations, we estimated the odds ratios (ORs) of COVID-19 vaccination in the 28 days before a SAB or last date of the surveillance period (index date) in ongoing pregnancies and occurrence of SAB, across cumulative 4-week periods from December 2020 through June 2021. Using data from a single site, we evaluated alternative methodological approaches: increasing the exposure window to 42 days, modifying the index date from the last day to the midpoint of the surveillance period, and constructing a cohort design with a time-dependent exposure model. A protective effect (OR = 0.78, 95% confidence interval: 0.69, 0.89), observed with 3-cumulative periods ending March 8, 2021, was attenuated when surveillance extended to June 28, 2021 (OR = 1.02, 95% confidence interval: 0.96, 1.08). We observed a lower OR for a 42-day window compared with a 28-day window. The time-dependent model showed no association. Timing of the surveillance appears to be an important factor affecting the observed vaccine-SAB association.

Follow-Up of Side Effects throughout the Entire Course of Coronavirus Vaccination

Vaccines are considered the best protective means against coronavirus infection. There is increasing interest in reporting the side effects of vaccines, especially for individuals younger than 18 years old. Accordingly, this analytical cohort study aims to report on the side effects of adult and young individuals who received vaccination within 24 h, 72 h, 5 days, and 1 week through the entire course of vaccination (ECoV). A validated online survey was used to collect information. In total, 1069 individuals were completely followed. Most individuals received the Pfizer vaccine (59.6%). Most individuals had received two doses (69.4%). Very strong and statistically significant associations with side effects (p < 0.05, Phi (Φ) > 0.25) throughout the ECoV were reported for the type of vaccine and female gender. Non-smokers reported weak statistically significant associations. Fatigue and localized pain were the most commonly reported side effect, with onset within 24 h and duration of less than 72 h. The prevalence of reported side effects was statistically significantly higher among young individuals (<18 years old) than among adults (X2 (1) =7.6, p = 0.006. Phi φ = 0.11).

Success of nano-vaccines against COVID-19: a transformation in nanomedicine

INTRODUCTION

The vaccines being used against COVID-19 are composed of either non-viral or viral nanoparticles (NPs). Nanotechnology-based vaccine technology was studied for its potentially transformative advancement of medicine.

AREAS COVERED

NPs protect the encapsulated mRNA in vaccines, thereby enhancing the stability of the ribonucleic acids and facilitating their intact delivery to their specific targets. Compared to liposomes, lipid nanoparticles (LNPs) are unique and, through their rigid morphology and better cellular penetrability, render enhanced cargo stability. To explore nanotechnology-mediated vaccine delivery and its potential in future pandemics, we assessed articles from various databases, such as PubMed, Embase, and Scopus, including editorial/research notes, expert opinions, and collections of data from several clinical research trials. In the current review, we focus on the nanoparticulate approach of the different SARS-CoV-2 vaccines and explore their success against the pandemic.

EXPERT OPINION

The mRNA-based vaccines, with their tremendous efficacy of ~95% (under phase III-IV clinical trials) and distinct nanocarriers (LNPs), represent a new medical front alongside DNA and siRNA-based vaccines.

Venous Thromboembolism following Two Doses of COVID-19 mRNA Vaccines in the US Population, 2020–2022

The COVID-19 mRNA vaccine is one of the most effective strategies used to fight against COVID-19. Recently, venous thromboembolism (VTE) events after COVID-19 mRNA vaccination have been reported in various research. Such a concern may hamper the ongoing COVID-19 vaccination campaign. Based on the US Vaccine Adverse Event Reporting System data, this modified self-controlled case series study investigated the association of COVID-19 mRNA vaccination with VTE events among US adults. We found the VTE incidence rate in the recommended dose interval does not change significantly after receiving COVID-19 mRNA vaccines. This conclusion still holds if the analysis is stratified by age and gender. The VTE onset may not be significantly associated with COVID-19 mRNA vaccination.

Comparability of clinical trials and spontaneous reporting data regarding COVID-19 vaccine safety

Severe adverse events (AEs) after COVID-19 vaccination are not well studied in randomized controlled trials (RCTs) due to rarity and short follow-up. To monitor the safety of COVID-19 vaccines ("Pfizer" vaccine dose 1 and 2, "Moderna" vaccine dose 1 and 2, and "Janssen" vaccine single dose) in the U.S., especially regarding severe AEs, we compare the relative rankings of these vaccines using both RCT and the Vaccine Adverse Event Reporting System (VAERS) data. The risks of local and systemic AEs were assessed from the three pivotal COVID-19 vaccine trials and also calculated in the VAERS cohort consisting of 559,717 reports between December 14, 2020 and September 17, 2021. AE rankings of the five vaccine groups calculated separately by RCT and VAERS were consistent, especially for systemic AEs. For severe AEs reported in VAERS, the reported risks of thrombosis and GBS after Janssen vaccine were highest. The reported risk of shingles after the first dose of Moderna vaccine was highest, followed by the second dose of the Moderna vaccine. The reported risk of myocarditis was higher after the second dose of Pfizer and Moderna vaccines. The reported risk of anaphylaxis was higher after the first dose of Pfizer vaccine. Limitations of this study are the inherent biases of the spontaneous reporting system data, and only including three pivotal RCTs and no comparison with other active vaccine safety surveillance systems.

The Importance of Vaccination in the Context of the COVID-19 Pandemic: A Brief Update Regarding the Use of Vaccines

The COVID-19 pandemic has led the world to undertake the largest vaccination campaign in human history. In record time, unprecedented scientific and governmental efforts have resulted in the acquisition of immunizers utilizing different technologies (nucleotide acids, viral vectors, inactivated and protein-based vaccines). Currently, 33 vaccines have already been approved by regulatory agencies in different countries, and more than 10 billion doses have been administered worldwide. Despite the undeniable impact of vaccination on the control of the pandemic, the recurrent emergence of new variants of interest has raised new challenges. The recent viral mutations precede new outbreaks that rapidly spread at global proportions. In addition, reducing protective efficacy rates have been observed among the main authorized vaccines. Besides these issues, several other crucial issues for the appropriate combatting of the pandemic remain uncertain or under investigation. Particularly noteworthy issues include the use of vaccine-boosting strategies to increase protection; concerns related to the long-term safety of vaccines, child immunization reliability and uncommon adverse events; the persistence of the virus in society; and the transition from a pandemic to an endemic state. In this review, we describe the updated scenario regarding SARS-CoV-2 variants and COVID-19 vaccines. In addition, we outline current discussions covering COVID-19 vaccine safety and efficacy, and the future pandemic perspectives.

In Defense of Vaccine Mandates: An Argument from Consent Rights

This article will focus on the ethical issues of vaccine mandates and stake claim to the relatively extreme position that outright requirements for people to receive the vaccine are ethically correct at both the governmental and institutional levels. One novel strategy employed here will be to argue that deontological considerations pertaining to consent rights cut as much in favor of mandating vaccines as against them. The presumption seems to be that arguments from consent speak semi-definitively against forcing people to inject something into their bodies, and so any argument in favor of mandates must produce different and overriding logical and ethical considerations. Our central claim will be that the same logic that might seem to prohibit vaccine mandates as violations of consent actually supports such mandates when viewed from the perspective of the potential bystander who might otherwise be exposed to COVID-19.

Current and future nanoparticle vaccines for COVID-19

COVID-19 has become a major cause of global mortality and driven massive health and economic disruptions. Mass global vaccination offers the most efficient pathway towards ending the pandemic. The development and deployment of first-generation COVID-19 vaccines, encompassing mRNA or viral vectors, has proceeded at a phenomenal pace. Going forward, nanoparticle-based vaccines which deliver SARS-CoV-2 antigens will play an increasing role in extending or improving vaccination outcomes against COVID-19. At present, over 26 nanoparticle vaccine candidates have advanced into clinical testing, with ∼60 more in pre-clinical development. Here, we discuss the emerging promise of nanotechnology in vaccine design and manufacturing to combat SARS-CoV-2, and highlight opportunities and challenges presented by these novel vaccine platforms.