The short term safety of COVID ‐19 vaccines in Australia: AusVaxSafety active surveillance, February – August 2021

A scoping review of active, participant centred, digital adverse events following immunization (AEFI) surveillance of WHO approved COVID-19 vaccines: A Canadian immunization Research Network study

This scoping review examines the role of digital solutions in active, participant-centered surveillance of adverse events following initial release of COVID-19 vaccines. The goals of this paper were to examine the existing literature surrounding digital solutions and technology used for active, participant centered, AEFI surveillance of novel COVID-19 vaccines approved by WHO. This paper also aimed to identify gaps in literature surrounding digital, active, participant centered AEFI surveillance systems and to identify and describe the core components of active, participant centered, digital surveillance systems being used for post-market AEFI surveillance of WHO approved COVID-19 vaccines, with a focus on the digital solutions and technology being used, the type of AEFI detected, and the populations under surveillance. The findings highlight the need for customized surveillance systems based on local contexts and the lessons learned to improve future vaccine monitoring and pandemic preparedness.

Non-linear effects of age in reporting of adverse events following influenza immunization in Zhejiang, China

BACKGROUND

Previous evidence had suggested age and sex affect the reporting rate of adverse events following immunization (AEFI), but with little exploration of potential their non-linear and interaction effects on AEFIs. Examining these non-linear effects could be beneficial for identifying high-risk populations.

METHODS

Using AEFI records and vaccination data from national passive surveillance system of adverse event following immunization and Zhejiang provincial immunization information system in the 2021-2022 influenza season, respectively. The effects of age and sex on AEFIs were analyzed through the generalized additive model (logistic regression with a smooth term) to estimate non-linear characteristics after adjusting for other co-variables (adopted significance level p < 0.05).

RESULTS

There were 1,259,975 influenza vaccine doses administered and 1304 AEFI records reported during the 2021-2022 influenza season, with a reporting rate of 10.35/10,000 doses. The odds of reporting an AEFI increased from 6 months of age, peaking at about 54 years of age, then gradually declined. The odds of females experiencing AEFIs are higher than that of males. The data model indicated clear effects of age, sex, and their interaction (p < 0.01) on reporting rate of AEFI. Concomitant vaccination and vaccine type were also the impact factors for reporting rate of AEFI.

CONCLUSION

This study revealed a non-linear property in age and the AEFI odds, with a significant interaction and higher reporting rate in females. In addition, the odds of AEFI increased with co-administration compared to separate vaccination.

Applying causal inference and Bayesian statistics to understanding vaccine safety signals using a simulation study

Community perception of vaccine safety influences vaccine uptake. Our objective was to assess current vaccine safety monitoring by examining factors that may influence the availability of post-vaccination survey data, and thereby the specificity and sensitivity of existing signal detection methods. We used causal directed acyclic graphs (DAGs) and a Bayesian posterior predictive analysis (PPA) signal detection method to understand biological and behavioural factors which may influence signal detection. The DAGs informed the data simulated for scenarios in which these factors were varied. The influence of biological factors such as severity of adverse reactions and behavioural factors such as healthcare-seeking behaviour upon survey participation was found to drive signal detection. Where there was a low prevalence of moderate to severe reactions, false signals were detected when there was a strong influence of reaction severity on both survey participation and seeking medical attention. These findings provide implications for future vaccine safety monitoring.

Short-Term Active Safety Surveillance of the Spikevax and Nuvaxovid Priming Doses in Australia

Australia commenced administration of the Spikevax (Moderna mRNA-1273) COVID-19 vaccine in August 2021 and Nuvaxovid (Novavax NVX-CoV2373) in January 2022. This study describes the short-term safety profile of priming doses of the Spikevax and Nuvaxovid vaccines given between September 2021 and September 2023. Online surveys were sent via AusVaxSafety, Australia's active vaccine safety surveillance system, three and eight days after vaccination. A total of 131,775 day 3 surveys were sent, with a response rate of 38.5% (N = 50,721). A total of 43,875 day 8 surveys matched with day 3 survey responses were sent, with a response rate of 71.5% (N = 31,355). Half (50.7%) of respondents reported any adverse event following immunisation (AEFI) in the 0-3 days after vaccination and 24.6% reported any AEFI 4-7 days after vaccination. Fatigue, local pain, headache, and myalgia were the most frequently reported symptoms for both vaccines in both periods. After adjusting for respondent characteristics, vaccination clinic type, jurisdiction, and medical conditions, the odds for reporting AEFI increased with age from 16-19 years to highest odds at 30-39 years, after which it declined. Females had greater odd of reporting AEFI than males across most age groups, vaccine types, and doses. Respondents with a history of anaphylaxis had greater odds of reporting any AEFI (adjusted OR range: 1.50-2.86). A total of 3.1% of respondents reported seeking medical review 0-3 days after vaccination. This study affirms the short-term safety of Spikevax and Nuvaxovid COVID-19 vaccine priming doses in a large sample in Australia.

Short-term COVID-19 vaccine adverse effects among adults in Ekiti State, Nigeria

BACKGROUND

The safety of the COVID-19 vaccines has been a topic of concern globally. This issue of safety is associated with vaccine hesitancy due to concerns about the adverse effects of the vaccines. Consequently, this study determined the short-term safety profile of the Oxford/AstraZeneca COVID-19 vaccine in Ekiti State, Nigeria.

METHODS

Descriptive cross-sectional study conducted between May and July 2021 among individuals who had received the first dose of the first batch of the Oxford/AstraZeneca COVID-19 vaccine at Ekiti State University Teaching Hospital (EKSUTH), Ado-Ekiti, Nigeria. A Google form was used to collect data on the adverse effects of the vaccine.

RESULTS

Out of over 1,000 individuals who were approached, 758 respondents completed the study. A large percentage (57.4%) of those who received the vaccines were healthcare workers. Adverse effects were reported in 70.8% of the participants with most manifesting on the first day of the vaccination. The predominant adverse effects were injection site soreness (28.5%), followed by fatigue (18.7%) and muscle pain (8.6%). There was no report of severe adverse effects such as anaphylactic reactions, thrombosis, myocarditis, transient myelitis, or Guillen-Barre syndrome.

CONCLUSION

This study found that self-reported adverse effects of the Oxford/AstraZeneca COVID-19 vaccine were mild and short in duration. This outcome has promising implications for improving COVID-19 vaccine uptake in the immediate environment and Nigeria.

A single blinded, phase IV, adaptive randomised control trial to evaluate the safety of coadministration of seasonal influenza and COVID-19 vaccines (The FluVID study)

OBJECTIVES

We evaluated the frequency of moderate and severe adverse events following coadministration of seasonal influenza vaccine (SIV) versus placebo with COVID-19 vaccines among adults to support practice guidelines.

METHODS

FluVID is a participant-blinded, phase IV, randomised control trial. On the same day as the participant's scheduled COVID-19 vaccine, participants were randomised to receive SIV or saline placebo; those assigned placebo at visit one then received SIV a week later, and vice versa. Self-reported adverse events were collected daily for seven days following each visit. The primary endpoint was any solicited adverse event of at least moderate severity occurring up to seven days following receipt of SIV or placebo. This was modelled using a Bayesian logistic regression model. Analyses were performed by COVID-19 vaccine type and dose number.

RESULTS

Overall, 248 participants were enrolled; of these, 195 had received BNT162b2 and 53 had received mRNA1273 COVID-19 vaccines according to national guidelines. After randomisation, 119 were assigned to receive SIV and 129 were assigned to receive placebo at visit one. Adverse events were most frequently reported as mild (grade 1) in nature. Among 142 BNT162b2 booster dose one and 43 BNT162b2 booster dose two recipients, the posterior median risk difference for moderate/severe adverse events following SIV versus placebo was 13% (95% credible interval [CrI] -0.03 to 0.27) and 13% (95%CrI -0.37 to 0.12), respectively. Among 18 mRNA1273 booster dose one and 35 mRNA1273 booster dose two recipients, the posterior median risk difference of moderate/severe adverse events following influenza vaccine versus placebo was 6% (95%CrI -0.29 to 0.41) and -4% (95%CrI -0.30 to 0.23), respectively.

CONCLUSION

Adverse events following SIV and COVID-19 co-administration were generally mild and occurred with similar frequency to events following COVID-19 vaccine alone. We found no evidence to justify routine separation of SIV and COVID-19 vaccine doses.

CLINICAL TRIAL REGISTRATION

ACTRN12621001063808.

Side Effects of COVID-19 Vaccines in Pregnant and Lactating Mexican Women and Breastfed Infants: A Survey-Based Study

COVID-19 vaccines' safety has been extensively studied; however, further analysis is required in pregnant women, nursing mothers, and breastfed infants. Our aim was to compare the extension and severity of self-reported COVID-19 vaccine side effects in pregnant and breastfeeding women, and breastfed infants. In this cross-sectional study, COVID-19-vaccinated subjects were enrolled using an online survey in Mexico. Women were classified by pregnancy and breastfeeding status at the time of vaccination (n = 3167). After the first or only dose, there was a trend toward fewer systemic effects in pregnant women (p = 0.06). BNT162b2 (Pfizer-BioNTech) had a higher frequency of local symptoms in pregnancy. Lactating women experienced fewer local symptoms after the first or single dose (p = 0.04) and the opposite occurred after the second dose (p = 0.001). ChAdOx1 (AstraZeneca) increased the chances of developing both local and systemic symptoms after the first dose but decreased them after the second dose. The severity was similar across groups, although the result of lack of association in pregnancy requires studies with a larger sample size. Irritability was the most reported symptom in breastfed infants. This study contributes to the knowledge about the side effects in pregnant and lactating women, and breastfed babies.

Comparison of Adverse Effects of Two SARS-CoV-2 Vaccines Administered in Workers of the University of Padova

Introduction: In Italy, on December 2020, workers in the education sector were identified as a priority population to be vaccinated against COVID-19. The first authorised vaccines were the Pfizer-BioNTech mRNA (BNT162b2) and the Oxford-AstraZeneca adenovirus vectored (ChAdOx1 nCoV-19) vaccines. Aim: To investigate the adverse effects of two SARS-CoV-2 vaccines in a real-life preventive setting at the University of Padova. Methods: Vaccination was offered to 10116 people. Vaccinated workers were asked to voluntarily report symptoms via online questionnaires sent to them 3 weeks after the first and the second shot. Results: 7482 subjects adhered to the vaccination campaign and 6681 subjects were vaccinated with ChAdOx1 nCoV-19 vaccine and 137 (fragile subjects) with the BNT162b2 vaccine. The response rate for both questionnaires was high (i.e., >75%). After the first shot, the ChAdOx1 nCoV-19 vaccine caused more fatigue (p < 0.001), headache (p < 0.001), myalgia (p < 0.001), tingles (p = 0.046), fever (p < 0.001), chills (p < 0.001), and insomnia (p = 0.016) than the BNT162b2 vaccine. After the second dose of the BNT162b2 vaccine, more myalgia (p = 0.033), tingles (p = 0.022), and shivers (p < 0.001) than the ChAdOx1 nCoV-19 vaccine were elicited. The side effects were nearly always transient. Severe adverse effects were rare and mostly reported after the first dose of the ChAdOx1 nCoV-19 vaccine. They were dyspnoea (2.3%), blurred vision (2.1%), urticaria (1.3%), and angioedema (0.4%). Conclusions: The adverse effects of both vaccines were transient and, overall, mild in severity.

Safety of Four COVID-19 Vaccines across Primary Doses 1, 2, 3 and Booster: A Prospective Cohort Study of Australian Community Pharmacy Vaccinations

Four COVID-19 vaccines are approved for use in Australia: Pfizer-BioNTech BNT162b2 (Comirnaty), AstraZeneca ChAdOx1 (Vaxzevria), Moderna mRNA-1273 (Spikevax) and Novavax NVX-CoV2373 (Nuvaxovid). We sought to examine adverse events following immunisation (AEFI) at days 3 and 42 after primary doses 1, 2, 3 and booster. We conducted active vaccine safety surveillance from 130 community pharmacies in Australia integrated with AusVaxSafety, between August 2021-April 2022. Main outcomes: AEFI at 0-3 days post-vaccination; medical review/advice at 3 days and 42 days post-vaccination; SARS-CoV-2 breakthrough infection by day 42. Of 110,024 completed day 3 surveys (43.6% response rate), 50,367 (45.8%) reported any AEFI (highest proportions: Pfizer 42%, primary dose 3; AstraZeneca 58.3%, primary dose 1; Moderna 65.4% and Novavax 58.8%, both primary dose 2). The most common AEFI reported across all doses/vaccines were local reactions, systemic aches and fatigue/tiredness. Overall, 2172/110,024 (2.0%) and 1182/55,329 (2.1%) respondents sought medical review at days 3 and 42, respectively, and 931/42,318 (2.2%) reported breakthrough SARS-CoV-2 infection at day 42. We identified similar AEFI profiles but at lower proportions than previously reported for Pfizer, AstraZeneca, Moderna and Novavax COVID-19 vaccines. Moderna vaccine was the most reactogenic and associated with higher AEFI proportions across primary doses 2, 3, and booster.