Active SMS-based surveillance of adverse events following immunisation with influenza and pertussis-containing vaccines in Australian pregnant women using AusVaxSafety

Active surveillance of immunization adverse effects: a multicentre, open-label, three-arm randomized uncontrolled trial in Ethiopia

BACKGROUND

Participant-centred active adverse event following immunization (AEFI) surveillance can offer real-time vaccine safety data and help in signal detection. This study aimed to evaluate the effectiveness of participant-centred active adverse events (AEs) surveillance following measles immunization in Gedeo Zone health facilities in Ethiopia.

METHODS

An open-label, multicentred, three-arm randomized uncontrolled trial was conducted from 1 June to 21 October 2023. After assessing enrolment eligibility, the study participants were randomized into three groups (short message service [SMS], telephone interview, and diary card). They were expected to report AEs in children 1 week after receiving immunization. Binary and multivariable logistic regression and χ2 tests were used to analyse the data.

RESULTS

Among the 396 participants randomized into the three groups, 80.8% (320 participants) reported back about their children's AE status. Participants in the telephone interview group exhibited a substantially superior response rate (93.2% of 132 participants; p<0.00001) compared with the SMS (71.2%) and diary card (78%) groups. The likelihood of reporting the status of AEs experienced by children was lower by 77% (adjusted odds ratio 0.23 [95% confidence interval 0.1 to 0.52], p-value <0.00001) in the diary card group compared with the telephone interview group.

CONCLUSIONS

In this study, a telephone interview was found to be the best method for AEFI reporting. Participant-centred active AE surveillance could potentially permit more rapid identification of emerging safety signals. Trial registration:  https://clinicaltrials.gov/ct2/show/NCT05803538.

Safety of influenza vaccination during pregnancy: a systematic review

OBJECTIVE

We conducted a systematic review to evaluate associations between influenza vaccination during pregnancy and adverse birth outcomes and maternal non-obstetric serious adverse events (SAEs), taking into consideration confounding and temporal biases.

METHODS

Electronic databases (Ovid MEDLINE ALL, Embase Classic+Embase and the Cochrane Central Register of Controlled Trials) were searched to June 2021 for observational studies assessing associations between influenza vaccination during pregnancy and maternal non-obstetric SAEs and adverse birth outcomes, including preterm birth, spontaneous abortion, stillbirth, small-for-gestational-age birth and congenital anomalies. Studies of live attenuated vaccines, single-arm cohort studies and abstract-only publications were excluded. Records were screened using a liberal accelerated approach initially, followed by a dual independent approach for full-text screening, data extraction and risk of bias assessment. Pairwise meta-analyses were conducted, where two or more studies met methodological criteria for inclusion. The Grading of Recommendations, Assessment, Development and Evaluation approach was used to assess evidence certainty.

RESULTS

Of 9443 records screened, 63 studies were included. Twenty-nine studies (24 cohort and 5 case-control) evaluated seasonal influenza vaccination (trivalent and/or quadrivalent) versus no vaccination and were the focus of our prioritised syntheses; 34 studies of pandemic vaccines (2009 A/H1N1 and others), combinations of pandemic and seasonal vaccines, and seasonal versus seasonal vaccines were also reviewed. Control for confounding and temporal biases was inconsistent across studies, limiting pooling of data. Meta-analyses for preterm birth, spontaneous abortion and small-for-gestational-age birth demonstrated no significant associations with seasonal influenza vaccination. Immortal time bias was observed in a sensitivity analysis of meta-analysing risk-based preterm birth data. In descriptive summaries for stillbirth, congenital anomalies and maternal non-obstetric SAEs, no significant association with increased risk was found in any studies. All evidence was of very low certainty.

CONCLUSIONS

Evidence of very low certainty suggests that seasonal influenza vaccination during pregnancy is not associated with adverse birth outcomes or maternal non-obstetric SAEs. Appropriate control of confounding and temporal biases in future studies would improve the evidence base.

Safety and Clinical Benefits of Adacel® and Adacel®-Polio Vaccination in Pregnancy: A Structured Literature Review

Vaccination in pregnancy using a tetanus toxoid, reduced dose diphtheria toxoid, and reduced dose acellular pertussis (Tdap) vaccine is important for prevention of severe pertussis disease in young infants. The objectives of this systematic literature review were to search for original research studies evaluating the vaccine effectiveness, immunogenicity, and safety of Adacel®/Adacel-Polio® used during pregnancy to prevent pertussis disease in young infants. Medical databases used included EMBASE, BIOSIS Previews, and Chemical Abstracts, with search terms related to pregnancy, vaccines/immunization, safety, pertussis, effectiveness/efficacy, and immune response; other potentially eligible reports were included where applicable. Search results were restricted to literature published from 1 January 1995 to 26 July 2021. A total of 2021 articles and 4 other reports were identified for primary review. A total of 49 publications qualified for inclusion after primary and secondary reviews. Effectiveness studies of Adacel or Adacel-Polio given in pregnancy consistently showed high levels of protection from pertussis disease in the newborn (vaccine effectiveness: 91-93%). In immunogenicity studies, the response in pregnant women was consistent with that of non-pregnant women. Infants of mothers vaccinated with Adacel or Adacel-Polio in pregnancy had higher anti-pertussis antibody levels at birth and at 2 months of age compared to infants born to women vaccinated with comparator vaccines, placebo, or those not vaccinated during pregnancy. There was evidence of a slightly decreased response to primary pertussis vaccination in infants of mothers vaccinated with Adacel or Adacel-Polio, but this was not thought to be clinically significant. In safety studies, Adacel or Adacel-Polio vaccination was well tolerated by pregnant woman and not associated with pregnancy, postpartum, or neonatal complications. In conclusion, Adacel or Adacel-Polio vaccination in pregnancy is highly effective in protecting young infants from pertussis disease, with a favorable safety profile for both pregnant women and their infants.

Information systems for vaccine safety surveillance

Immunization implementation in the community relies upon post-licensure vaccine safety surveillance to maintain safe vaccination programs and to detect rare AEFI not observed in clinical trials. The increasing availability of electronic health-care related data and correspondence from both health-related providers and internet-based media has revolutionized health-care information. Many and varied forms of health information related to adverse event following immunization (AEFI) are potentially suitable for vaccine safety surveillance. The utilization of these media ranges from more efficient use of electronic spontaneous reporting, automated solicited surveillance methods, screening various electronic health record types, and the utilization of natural language processing techniques to scan enormous amounts of internet-based data for AEFI mentions. Each of these surveillance types have advantages and disadvantages and are often complementary to each other. Most are "hypothesis generating," detecting potential safety signals, where some, such as vaccine safety datalinking, may also serve as "hypothesis testing" to help verify and investigate those potential signals.

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

Objective:

To assess the short term safety of the COVID‐19 vaccines Comirnaty (Pfizer–BioNTech BNT162b2) and Vaxzevria (AstraZeneca ChAdOx1) in Australia.

Design:

Prospective observational cohort study; online surveys by AusVaxSafety, a national active vaccine safety surveillance system, three and eight days after vaccination.

Setting, participants:

People aged 16 years or more who received COVID‐19 vaccines at sentinel vaccination hubs, general practices, or Aboriginal Community Controlled Health Organisation clinics, 22 February – 30 August 2021.

Main outcome measures:

Primary outcome: proportion of respondents who reported any adverse event following immunisation (AEFI) 0–3 days after vaccination. Secondary outcomes: proportions of respondents who reported specific adverse events or medical review for AEFI within seven days of vaccination; impact on usual daily activities; recovery.

Results:

4 851 480 people received COVID‐19 vaccines at participating sentinel sites during the study period (25% of all COVID‐19 vaccine doses administered in Australia to 30 August 2021). 3 035 983 people responded to both surveys (response rate, 62.6%); 35.9% of respondents reported one or more AEFI 0–3 days after Comirnaty dose 1, 54.7% after Comirnaty dose 2, 52.8% after Vaxzevria dose 1, and 22.0% after Vaxzevria dose 2. Local pain, fatigue, headache, and myalgia were the most frequently reported symptoms. After adjusting for demographic characteristics, vaccination site type, jurisdiction, and self‐reported medical conditions, the odds of reporting any AEFI were higher for women than men (range of adjusted odd ratios [aORs], by vaccine and dose, 1.53–1.84), for people with a history of anaphylaxis (aOR range, 1.28–1.45), and for people reporting certain underlying conditions, including obesity (aOR range, 1.15–1.75), immunodeficiency (aOR range, 1.04–2.24), or chronic inflammatory disease (aOR range, 1.05–1.75). 0.9% of respondents sought medical advice in the three days following vaccination, most frequently after Comirnaty dose 2 (1.4%) and Vaxzevria dose 1 (1.2%).

Conclusion:

AusVaxSafety active surveillance affirms the short term safety profile of Comirnaty and Vaxzevria vaccines in a large population sample during the first six months of the Australian COVID‐19 vaccination program.

A scoping review of active, participant-centred, digital adverse events following immunization (AEFI) surveillance: A Canadian immunization research network study

BACKGROUND

Post-licensure adverse events following immunization (AEFI) surveillance is conducted to monitor vaccine safety, such as identifying batch/brand issues and rare reactions, which consequently improves community confidence. The integration of technology has been proposed to improve AEFI surveillance, however, there is an absence of description regarding which digital solutions are successfully being used and their unique characteristics.

OBJECTIVES

The objectives of this scoping review were to 1) map the research landscape on digital systems used for active, participant-centred, AEFI surveillance and 2) describe their core components.

METHODS

We conducted a scoping review informed by the PRISMA Extension for Scoping Reviews (PRSIMA-ScR) guideline. OVID-Medline, Embase Classic + Embase, and Medrxiv were searched by a medical librarian from January 1, 2000 to January 28th, 2021. Two independent reviewers determined which studies met inclusion based on pre-specified eligibility criteria. Data extraction was conducted using pre-made tables with specific variables by one investigator and verified by a second.

RESULTS

Twenty-seven publications met inclusion, the majority of which came from Australia (n = 15) and Canada (n = 6). The most studied active, participant-centred, digital AEFI surveillance systems were SmartVax (n = 8) (Australia), Vaxtracker (n = 7) (Australia), and Canadian National Vaccine Safety (CANVAS) Network (Canada) (n = 6). The two most common methods of communicating with vaccinees reported were short-message-service (SMS) (n = 15) and e-mail (n = 14), with online questionnaires being the primary method of data collection (n = 20).

CONCLUSION

Active, participant-centred, digital AEFI surveillance is an area actively being researched as depicted by the literature landscape mapped by this scoping reviewWe hypothesize that the AEFI surveillance approach herein described could become a primary method of collecting self-reported subjective symptoms and reactogenicity from vaccinees, complementing existing systems. Future evaluation of identified digital solutions is necessary to bring about improvements to current vaccine surveillance systems to meet contemporary and future public health needs.

The safety of co-administration of Bacille Calmette-Guérin (BCG) and influenza vaccines

Background

With the emergence of novel vaccines and new applications for older vaccines, co-administration is increasingly likely. The immunomodulatory effects of BCG could theoretically alter the reactogenicity of co-administered vaccines. Using active surveillance in a randomised controlled trial, we aimed to determine whether co-administration of BCG vaccination changes the safety profile of influenza vaccination.

Methods

Participants who received influenza vaccine alone (Influenza group) were compared with those who also received BCG-Denmark vaccine in the contralateral arm (Influenza+BCG group). Data on the influenza vaccination site were collected using serial questionnaires and active follow-up for 3 months post vaccination.

Results

Of 1351 participants in the Influenza+BCG group and 1418 participants in the Influenza group, 2615 (94%) provided influenza vaccine safety data. There was no significant difference in the proportion of participants with any local adverse reaction between the Influenza+BCG group and the Influenza group (918/1293 [71.0%] versus (906/1322 [68.5%], p = 0.17). The proportion of participants reporting any pain, erythema and tenderness at the influenza vaccination site were similar in both groups. Swelling was less frequent (81/1293 [6.3%] versus 119/1322 (9.0%), p = 0.01) and the maximal diameter of erythema was smaller (mean 1.8 cm [SD 2.0] versus 3.0 cm [SD 2.5], p<0.001) in the Influenza+BCG group. Sixteen participants reported serious adverse events: 9 participants in the Influenza+BCG group and 7 in the Influenza group.

Conclusions

Adverse events following influenza vaccination are not increased when BCG is co-administered.

Safety of vaccines used for routine immunization in the United States: An updated systematic review and meta-analysis

BACKGROUND

Understanding the safety of vaccines is critical to inform decisions about vaccination. Our objective was to conduct a systematic review of the safety of vaccines recommended for children, adults, and pregnant women in the United States.

METHODS

We searched the literature in November 2020 to update a 2014 Agency for Healthcare Research and Quality review by integrating newly available data. Studies of vaccines that used a comparator and reported the presence or absence of key adverse events were eligible. Adhering to Evidence-based Practice Center methodology, we assessed the strength of evidence (SoE) for all evidence statements. The systematic review is registered in PROSPERO (CRD42020180089).

RESULTS

Of 56,603 reviewed citations, 338 studies reported in 518 publications met inclusion criteria. For children, SoE was high for no increased risk of autism following measles, mumps, and rubella (MMR) vaccine. SoE was high for increased risk of febrile seizures with MMR. There was no evidence of increased risk of  intussusception with rotavirus vaccine at the latest follow-up (moderate SoE), nor of diabetes (high SoE). There was no evidence of increased risk or insufficient evidence for key adverse events for newer vaccines such as 9-valent human papillomavirus and meningococcal B vaccines. For adults, there was no evidence of increased risk (varied SoE) or insufficient evidence for key adverse events for the new adjuvanted inactivated influenza vaccine and recombinant adjuvanted zoster vaccine. We found no evidence of increased risk (varied SoE) for key adverse events among pregnant women following tetanus, diphtheria, and acellular pertussis vaccine, including stillbirth (moderate SoE).

CONCLUSIONS

Across a large body of research we found few associations of vaccines and serious key adverse events; however, rare events are challenging to study. Any adverse events should be weighed against the protective benefits that vaccines provide.

Efficacy and safety of influenza vaccination during pregnancy: realizing the potential of maternal influenza immunization

Introduction: Pregnant women are at higher risk of severe complications following influenza infection compared to the general population. Influenza vaccination during pregnancy can offer direct protection to pregnant women and passive immunity to infants up to 6 months of age via maternal antibodies. Pregnant women are a high priority group for influenza immunization.Areas covered: This review provides an overview of the basis for recommending influenza vaccine to pregnant women, current immunization policies, the evidence supporting the safety and effectiveness of maternal vaccination, and future research needed. We conducted a search of PubMed for articles describing the safety or efficacy of influenza vaccines administered during pregnancy. Published articles from inception to 17 November 2020 were reviewed.Expert opinion: Experimental and observational evidence support the efficacy, effectiveness and safety of influenza immunization during pregnancy. These data support the continued provision of inactivated influenza vaccine to pregnant women, as recommended by global immunization policies. To achieve success with maternal influenza immunization programs, further work is needed to inform policy development in low- and middle-income settings and implementation and promotion in high-income settings.

SAEFVIC: Surveillance of adverse events following immunisation (AEFI) in Victoria, Australia, 2018

Background

SAEFVIC is the Victorian surveillance system for adverse events following immunisation (AEFI). It enhances passive surveillance by also providing clinical support and education to vaccinees and immunisation providers. This report summarises surveillance, clinical and vaccine pharmacovigilance activities of SAEFVIC in 2018.

Methods

A retrospective observational cohort study of AEFI reports received by SAEFVIC in 2018, compared with previous years since 2008. Data were categorised by vaccinee demographics of age, sex, pregnancy and Indigenous status, vaccines administered and AEFI reactions reported. Age cohorts were defined as infant (0-12 months); young child (1-4 years); school-aged (5-17 years); adult (18-64 years); and older person (65+ years). Proportional reporting ratios were calculated for signal investigation of serious adverse neurological events with all vaccines and with influenza vaccines. Clinical support services and educational activities are described.

Results

SAEFVIC received 1730 AEFI reports (26.8 per 100,000 population), with 9.3% considered serious. Nineteen percent (n = 329) attended clinical review. Annual AEFI reporting trends increased for infants, children and older persons, but were stable for school-aged and adult cohorts. Females comprised 55% of all reports and over 80% of reports among adults. There were 17 reports of AEFI in pregnant women and 12 (0.7%) in persons identifying as Indigenous Australians. A possible signal regarding serious adverse neurological events (SANE) was detected, but was not supported by signal validation testing. A clinical investigation is ongoing. Two deaths were reported coincident to immunisation with no evidence of causal association.

Conclusion

SAEFVIC continues to provide robust AEFI surveillance supporting vaccine safety monitoring in Victoria and Australia, with new signal detection and validation methodologies strengthening capabilities.