Comparing Reactogenicity of COVID-19 vaccines: a systematic review and meta-analysis

Unlocking cancer vaccine potential: What are the key factors?

Cancer is a global health challenge, with changing demographics and lifestyle factors producing an increasing burden worldwide. Screening advancements are enabling earlier diagnoses, but current cancer immunotherapies only induce remission in a small proportion of patients and come at a high cost. Cancer vaccines may offer a solution to these challenges, but they have been mired by poor results in past decades. Greater understanding of tumor biology, coupled with the success of vaccine technologies during the COVID-19 pandemic, has reinvigorated cancer vaccine development. With the first signs of efficacy being reported, cancer vaccines may be beginning to fulfill their potential. Solid tumors, however, present different hurdles than infectious diseases. Combining insights from previous cancer vaccine clinical development and contemporary knowledge of tumor immunology, we ask: who are the 'right' patients, what are the 'right' targets, and which are the 'right' modalities to maximize the chances of cancer vaccine success?

Comparison of Adverse Events and Antibody Responses Among Different COVID-19 Vaccination Schedules

Global investment in developing COVID-19 vaccines has been substantial, but vaccine hesitancy has emerged due to misinformation. Concerns about adverse events, vaccine shortages, dosing confusion, mixing vaccines, and access issues contribute to hesitancy. Initially, the WHO recommended homologous vaccination (same vaccine for both doses), but evolving factors led to consideration of heterologous vaccination (different vaccines). The study compared reactogenicity and antibody response for both viral protein spike (S) and nucleocapsid (N) in 205 participants who received three vaccination regimens: same vaccine for all doses (Pfizer), two initial doses of the same vaccine (CoronaVac or AstraZeneca), and a Pfizer booster. ChAdOx1 and BNT162b2 vaccines were the most reactogenic vaccines, while CoronaVac vaccine was the least. ChAdOx1 and BNT162b2 achieved 100% of S-IgG seropositivity with one dose, while CoronaVac required two doses, emphasizing the importance of the second dose in achieving complete immunization across the population with different vaccine regimes. Pfizer recipients showed the highest S-IgG antibody titers, followed by AstraZeneca recipients, both after the first and second doses. A third vaccine dose was essential to boost the S-IgG antibodies and equalize the antibody levels among the different vaccine schedules. CoronaVac induced N-IgG antibodies, while in the Pfizer and AstraZeneca groups, they were induced by a natural infection, reinforcing the role of N protein as a biomarker of infection.

The Novavax Heterologous Coronavirus Disease 2019 Booster Demonstrates Lower Reactogenicity Than Messenger RNA: A Targeted Review

Coronavirus disease 2019 (COVID-19) continues to be a global health concern, and booster doses are necessary for maintaining vaccine-mediated protection, limiting the spread of severe acute respiratory syndrome coronavirus 2. Despite multiple COVID-19 vaccine options, global booster uptake remains low. Reactogenicity, the occurrence of adverse local/systemic side effects, plays a crucial role in vaccine uptake and acceptance, particularly for booster doses. We conducted a targeted review of the reactogenicity of authorized/approved messenger RNA (mRNA) and protein-based vaccines demonstrated by clinical trials and real-world evidence. It was found that mRNA-based boosters show a higher incidence and an increased severity of reactogenicity compared with the Novavax protein-based COVID-19 vaccine (NVX-CoV2373). In a recent study from the National Institute of Allergy and Infectious Diseases, the incidence of pain/tenderness, swelling, erythema, fatigue/malaise, headache, muscle pain, or fever was higher in individuals boosted with BNT162b2 (0.4% to 41.6% absolute increase) or mRNA-1273 (5.5% to 55.0% absolute increase) compared with NVX-CoV2373. Evidence suggests that NVX-CoV2373, when utilized as a heterologous booster, demonstrates less reactogenicity compared with mRNA vaccines, which, if communicated to hesitant individuals, may strengthen booster uptake rates worldwide. Clinical Trials Registration NCT04889209.

Reactogenicity Differences between Adjuvanted, Protein-Based and Messenger Ribonucleic Acid (mRNA)-Based COVID-19 Vaccines

Participants in studies investigating COVID-19 vaccines commonly report reactogenicity events, and concerns about side effects may lead to a reluctance to receive updated COVID-19 vaccinations. A real-world, post hoc analysis, observational 2019nCoV-406 study was conducted to examine reactogenicity within the first 2 days after vaccination with either a protein-based vaccine (NVX-CoV2373) or an mRNA vaccine (BNT162b2 or mRNA-1273) in individuals who previously completed a primary series. Propensity score adjustments were conducted to address potential confounding. The analysis included 1130 participants who received a booster dose of NVX-CoV2373 (n = 303) or an mRNA vaccine (n = 827) during the study period. Within the first 2 days after vaccination, solicited systemic reactogenicity events (adjusted) were reported in 60.5% of participants who received NVX-CoV2373 compared with 84.3% of participants who received an mRNA vaccine; moreover, 33.9% and 61.4%, respectively, reported ≥3 systemic reactogenicity symptoms. The adjusted mean (95% CI) number of systemic symptoms was 1.8 (1.6-2.0) and 3.2 (3.0-3.4), respectively. Local reactogenicity events (adjusted) were reported in 73.4% and 91.7% of participants who received NVX-CoV2373 and mRNA vaccines, respectively; the adjusted mean (95% CI) number of local symptoms was 1.5 (1.33-1.61) and 2.4 (2.31-2.52), respectively. These results support the use of adjuvanted, protein-based NVX-CoV2373 as an immunization option with lower reactogenicity than mRNAs.

COVID-19 vaccine reactogenicity among participants enrolled in the GENCOV study

BACKGROUND

GENCOV is a prospective, observational cohort study of COVID-19-positive adults. Here, we characterize and compare side effects between COVID-19 vaccines and determine whether reactogenicity is exacerbated by prior SARS-CoV-2 infection.

METHODS

Participants were recruited across Ontario, Canada. Participant-reported demographic and COVID-19 vaccination data were collected using a questionnaire. Multivariable logistic regression was performed to assess whether vaccine manufacturer, type, and previous SARS-CoV-2 infection are associated with reactogenicity.

RESULTS

Responses were obtained from n = 554 participants. Tiredness and localized side effects were the most common reactions across vaccine doses. For most participants, side effects occurred and subsided within 1-2 days. Recipients of Moderna mRNA and AstraZeneca vector vaccines reported reactions more frequently compared to recipients of a Pfizer-BioNTech mRNA vaccine. Previous SARS-CoV-2 infection was independently associated with developing side effects.

CONCLUSIONS

We provide evidence of relatively mild and short-lived reactions reported by participants who have received approved COVID-19 vaccines.

A Predictive Model of Vaccine Reactogenicity Using Data from an In Vitro Human Innate Immunity Assay System

A primary concern in vaccine development is safety, particularly avoiding an excessive immune reaction in an otherwise healthy individual. An accurate prediction of vaccine reactogenicity using in vitro assays and computational models would facilitate screening and prioritization of novel candidates early in the vaccine development process. Using the modular in vitro immune construct model of human innate immunity, PBMCs from 40 healthy donors were treated with 10 different vaccines of varying reactogenicity profiles and then cell culture supernatants were analyzed via flow cytometry and a multichemokine/cytokine assay. Differential response profiles of innate activity and cell viability were observed in the system. In parallel, an extensive adverse event (AE) dataset for the vaccines was assembled from clinical trial data. A novel reactogenicity scoring framework accounting for the frequency and severity of local and systemic AEs was applied to the clinical data, and a machine learning approach was employed to predict the incidence of clinical AEs from the in vitro assay data. Biomarker analysis suggested that the relative levels of IL-1B, IL-6, IL-10, and CCL4 have higher predictive importance for AE risk. Predictive models were developed for local reactogenicity, systemic reactogenicity, and specific individual AEs. A forward-validation study was performed with a vaccine not used in model development, Trumenba (meningococcal group B vaccine). The clinically observed Trumenba local and systemic reactogenicity fell on the 26th and 93rd percentiles of the ranges predicted by the respective models. Models predicting specific AEs were less accurate. Our study presents a useful framework for the further development of vaccine reactogenicity predictive models.

Burden and Impact of Reactogenicity among Adults Receiving COVID-19 Vaccines in the United States and Canada: Results from a Prospective Observational Study

As SARS-CoV-2 variants continue to emerge, vaccination remains a critical tool to reduce the COVID-19 burden. Vaccine reactogenicity and the impact on work productivity/daily activities are recognized as contributing factors to vaccine hesitancy. To encourage continued COVID-19 vaccination, a more complete understanding of the differences in reactogenicity and impairment due to vaccine-related side effects across currently available vaccines is necessary. The 2019nCoV-406 study (n = 1367) was a prospective observational study of reactogenicity and associated impairments in adults in the United States and Canada who received an approved/authorized COVID-19 vaccine. Compared with recipients of mRNA COVID-19 booster vaccines, a smaller percentage of NVX-CoV2373 booster recipients reported local and systemic reactogenicity. This study's primary endpoint (percentage of participants with ≥50% overall work impairment on ≥1 of the 6 days post-vaccination period) did not show significant differences. However, the data suggest that NVX-CoV2373 booster recipients trended toward being less impaired overall than recipients of an mRNA booster; further research is needed to confirm this observed trend. The results of this real-world study suggest that NVX-CoV2373 may be a beneficial vaccine option with limited impact on non-work activities, in part due to the few reactogenicity events after vaccination.

Comparing reactogenicity of COVID-19 vaccine boosters: a systematic review and meta-analysis

INTRODUCTION

Different COVID-19 vaccines are being utilized as boosters. This systematic review and meta-analysis aims to evaluate the reactogenicity of COVID-19 vaccines given as booster doses, according to vaccine type, dose, timing, participant characteristics and primary immunization regimen received.

METHODS

Four databases (MEDLINE, Embase, Web of Science and CENTRAL) were searched for randomized controlled trials between 1 January 2020 and 1 January 2023 according to predetermined criteria.

RESULTS

Twenty-eight studies describing 19 vaccines of four different types (viral vector, inactivated, mRNA and protein sub-unit) were identified. BNT162b2 vaccine (Pfizer-BioNTech) was selected as the control as it was most often compared with other vaccines. Fever, fatigue, headache, injection-site pain, redness, and swelling were the most frequently reported solicited events. mRNA vaccines were the most reactogenic, followed by viral vector vaccines and protein sub-unit vaccines, while inactivated vaccines were the least reactogenic. Full-dose vaccines were more reactogenic than half-dose vaccines. Heterologous BNT162b2 boosters were more reactogenic than boosters with the same vaccine used for primary immunization.

CONCLUSIONS

COVID-19 vaccine booster schedules have distinct reactogenicity profiles, dependent on dose and vaccine type, which may allow targeted recommendations and provide choice for specific populations. Greater standardization of adverse event reporting will aid future studies.

Incorporation of 5 methylcytidine alleviates innate immune response to self-amplifying RNA vaccine

In order to improve vaccine effectiveness and safety profile of existing synthetic RNA-based vaccines, we have developed a self-amplifying RNA (saRNA)-based vaccine expressing membrane-anchored receptor binding domain (RBD) of SARS-CoV-2 S protein (S-RBD) and have demonstrated that a minimal dose of this saRNA vaccine elicits robust immune responses. Results from a recent clinical trial with 5-methylcytidine (5mC) incorporating saRNA vaccine demonstrated reduced vaccine-induced adverse effects while maintaining robust humoral responses. In this study, we investigate the mechanisms accounting for induction of efficient innate and adaptive immune responses and attenuated adverse effects induced by the 5mC-incorporated saRNA. We show that the 5mC-incorporating saRNA platform leads to prolonged and robust expression of antigen, while induction of type-I interferon (IFN-I), a key driver of reactogenicity, is attenuated in peripheral blood mononuclear cells (PBMCs), but not in macrophages and dendritic cells. Interestingly, we find that the major cellular source of IFN-I production in PBMCs is plasmacytoid dendritic cells (pDCs), which is attenuated upon 5mC incorporation in saRNA. In addition, we demonstrate that monocytes also play an important role in amplifying proinflammatory responses. Furthermore, we show that the detection of saRNA is mediated by a host cytosolic RNA sensor, RIG-I. Importantly, 5mC-incorporating saRNA vaccine candidate produced robust IgG responses against S-RBD upon injection in mice, thus providing strong support for the potential clinical use of 5mC-incorporating saRNA vaccines.

mRNA vaccines against respiratory viruses

PURPOSE OF REVIEW

The successes of the coronavirus disease 2019 (COVID-19) mRNA vaccines have accelerated the development of mRNA vaccines against other respiratory pathogens. The aim of this review is to highlight COVID-19 mRNA vaccine advances and provide an update on the progress of mRNA vaccine development against other respiratory pathogens.

RECENT FINDINGS

The COVID-19 mRNA vaccines demonstrated effectiveness in preventing severe COVID-19 and death. H7N9 and H10N8 avian influenza mRNA vaccines have demonstrated safety and immunogenicity in phase 1 clinical trials. Numerous seasonal influenza mRNA vaccines are in phase 1-3 clinical trials. Respiratory syncytial virus (RSV) mRNA vaccines have progressed to phase 2-3 clinical trials in adults and a phase 1 clinical trial in children. A combined human metapneumovirus and parainfluenza-3 mRNA vaccines was found to be well tolerated and immunogenic in a phase 1 trial among adults and trials are being conducted among children. Clinical trials of mRNA vaccines combining antigens from multiple respiratory viruses are underway.

SUMMARY

The development of mRNA vaccines against respiratory viruses has progressed rapidly in recent years. Promising vaccine candidates are moving through the clinical development pathway to test their efficacy in preventing disease against respiratory viral pathogens.

[Pharmacovigilance of vaccines against COVID-19 in community pharmacies. Results after the second dose and comparison between both]

Aim

Detection and tracing of suspicious adverse reactions (ARs) in community pharmacies after the second of COVID-19 vaccine dose. Comparison between doses.

Methods

Design: prospective observational study.

Subjects

Vaccinated against COVID-19, of legal age, who consent to participate.

Variables

Number and percentage of participants with ARs. Number, type and frequency of ARs. Impact on their daily life. Relations between variables.Approved by the Galician Ethical Committee of Research with medicines.

Results

693 participants with the 2nd dose, 63.6% women. Age 56.8 years. 312 (45.0%) vaccinated, 49.4% women and 37.3% men (p<0.0001), reported at least one AR: 43.9% with Comirnaty®, 37.7% with Vaxzevria®, 63.0% with Spikevax®.There were 972 ARs, 75.2% in women and 24.8% in men (p<0.0001). Mean 1.4/vaccinated (maximum 11). The most prevalent AR: pain at injection site 197 (28.4%), tiredness/fatigue 141 (20.3%), myalgia 112 (16.2%), headache 95 (13.7%), fever 84 (12.1%).51 participants with ARs needed professional help: 10 from the doctor, 6 in the emergency room, 3 in hospitals (1 referral), 33 in the pharmacy. 70 (15.1%) were prevented from their daily activity. 201 Ars from vaccinated persons were reported.Number of people vaccinated with ARs and the number of ARs were less with the 2nd dose (p<0.05).Inverse relationship (p<0.05) between "age" and "number of vaccinated with ARs", "need for professional care" and "prevented daily activity".

Conclusions

The number of vaccinated participants with ARs and their number was also high with the second dose, although lower than with the first. Women and younger people are predictive of increased risk of AR after vaccination against COVID-19.

Reactogenicity within the first week after Sinopharm, Sputnik V, AZD1222, and COVIran Barekat vaccines: findings from the Iranian active vaccine surveillance system

BACKGROUND

This study aimed to evaluate the reactogenicity effects of COVID-19 vaccines, used in Iran.

METHODS

At least 1000 people were followed up with phone calls or self-report in a mobile application within 7 days after vaccination. Local and systemic reactogenicities were reported overall and by subgroups.

RESULTS

The presence of one or more local and systemic adverse effects after the first dose of vaccines was 58.9% [(95% Confidence Intervals): 57.5-60.3)] and 60.5% (59.1-61.9), respectively. These rates were reduced to 53.8% (51.2-55.0) and 50.8% (48.8-52.7) for the second dose. The most common local adverse effect reported for all vaccines was pain in the injection site. During the first week after the first dose of vaccines, the frequency of the pain for Sinopharm, AZD1222, Sputnik V, and Barekat was 35.5%, 86.0%, 77.6%, and 30.9%, respectively. The same rates after the second dose were 27.3%, 66.5%, 63.9%, and 49.0%. The most common systemic adverse effect was fatigue. In the first dose, it was 30.3% for Sinopharm, 67.4% for AZD1222, 47.6% for Sputnik V, and 17.1% for Barekat. These rates were reduced to 24.6%, 37.1%, 36.5%, and 19.5%, in the second dose of vaccines. AZD1222 had the highest local and systemic adverse effects rates. The odds ratio of local adverse effects of the AZD1222 vaccine compared to the Sinopharm vaccine were 8.73 (95% CI 6.93-10.99) in the first dose and 4.14 (95% CI 3.32-5.17) in the second dose. Barekat and Sinopharm had the lowest frequency of local and systemic adverse effects. Compared to Sinopharm, systemic adverse effects were lower after the first dose of Barekat (OR = 0.56; 95% CI 0.46-0.67). Reactogenicity events were higher in women and younger people. Prior COVID-19 infection increased the odds of adverse effects only after the first dose of vaccines.

CONCLUSIONS

Pain and fatigue were the most common reactogenicities of COVID-19 vaccination. Reactogenicities were less common after the second dose of the vaccines. The adverse effects of AZD1222 were greater than those of other vaccines.

The Incidence and Effect of Adverse Events Due to COVID-19 Vaccines on Breakthrough Infections: Decentralized Observational Study With Underrepresented Groups

Background

Despite continuing efforts to improve the inclusion of underserved groups in clinical research, gaps in diversity remain. Participation of special populations is especially important when facing problems of unprecedented complexity such as the COVID-19 pandemic. A better understanding of factors associated with the immune response in diverse populations would advance future preventive and curative approaches.

Objective

The objective of this study was to investigate the factors potentially responsible for adverse events following COVID-19 immunization. The study population included adults from rural areas, transitional countries, and those with medically understudied conditions, across a broad age range.

Methods

The study evolved from peer support networks developed during the COVID-19 pandemic. Participants were recruited digitally through online neighborhood and health communities. Some of the participants volunteered as study investigators assisting with offline recruitment and safety monitoring. Individuals who consented to participate were asked to share their vaccination experiences either using constantly evolving web-based surveys or via one-on-one communication. Inferential statistical analysis to estimate differences between study groups was performed using parametric and nonparametric tests.

Results

Of 1430 participants who shared their vaccination experiences, 648 had outcome measures at their 1.5-year follow-up. Significant differences were found between age groups, types of vaccine adverse events (VAEs), incidences of breakthrough infections, and health conditions linked to the microbiome. Pairwise comparisons showed that VAEs interfering with daily activities were significantly higher in both younger (18-59 years) and older age groups (80-100 years, P<.001) than in the 60-79–year age group. Short-term VAEs were associated with lower incidence of breakthrough COVID-19 infections relative to those who reported either minimal or long-term adverse events (P<.001). A genetic origin was suggested for some adverse reactions.

Conclusions

The findings of this study demonstrate that vaccine adverse reactions in older individuals are being overlooked, and the incidence of VAEs impairing immunity may be higher than previously perceived. Better preventive measures are needed for all those at risk for life-threatening and long-term adverse events due to vaccination. Supportive community-based studies focusing on these populations could add important data to the current body of knowledge. Further and more comprehensive studies should follow.

Trial Registration

ClinicalTrials.gov NCT04832932; https://clinicaltrials.gov/ct2/show/NCT04832932

International Registered Report Identifier (IRRID)

RR2-10.1101/2021.06.28.21256779