Risk of Fatal Adverse Events after H1N1 Influenza Vaccine: Limitations of Passive Surveillance Data

McNeil, Michael M.; Broder, Karen R.; Vellozzi, Claudia; DeStefano, Frank

doi:10.1086/656295

Cited by 7 publications

(6 citation statements)

References 4 publications

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“…Non-vaccination has been quite extensively studied and Table 7 shows some of the commonest reasons for non-vaccination [ 15 ]. One specific example specifically related to this topic is the aforementioned 2009 H1N1 influenza vaccine which was initially claimed to have had associated mortality using the Vaccine Adverse Event Reporting System(VAERS) system, a claim which was eventually disproved but not before undermining public confidence in this important vaccine [ 16 ].…”

Section: Discussionmentioning

confidence: 99%

Withdrawn: Vaccine hesitancy among Maltese Healthcare workers toward influenza and novel COVID-19 vaccination

Grech

Gauci

Agius

2020

Early Human Development

113

112

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Introduction Vaccine hesitancy is a chronic public health threat. This study was carried out to ascertain Maltese healthcare workers' hesitancy to a novel COVID-19 vaccine and correlate this with influenza vaccine uptake. Methods A short, anonymous questionnaire was sent out to all of Malta's government sector healthcare workers via the service's standard email services (11–19/09/2020). A total of 9681 questionnaires were posted electronically, with 10.4% response. Results The proportion of Maltese healthcare workers who will take the influenza vaccine increased significantly. Doctors had the highest baseline uptake and highest likely influenza vaccine uptake next winter. The likely/undecided/unlikely to take a COVID-19 vaccine were 52/22/26% respectively. Males were likelier to take the vaccine. Doctors were the occupation with the highest projected vaccine uptake. Likelihood of taking COVID-19 vaccine was directly related to the likelihood of influenza vaccination. Concerns raised were related to insufficient knowledge about such a novel vaccine, especially unknown long term side effects. Discussion The increased uptake of influenza vaccine is probably due to increased awareness of respiratory viral illness. Doctors may have higher vaccine uptakes due to greater awareness and knowledge of vaccine safety. The proportions of who are likely/undecided/unlikely (half, quarter, quarter respectively) to take a COVID-19 are similar to rates reported in other countries. The higher male inclination to take the vaccine may be due the innate male propensity for perceived risk taking. Shared COVID-19 with influenza vaccine hesitancy implies an innate degree of vaccine reluctance/hesitancy and not merely reluctance based on novel vaccine knowledge gap.

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Section: Discussionmentioning

confidence: 99%

Withdrawn: Vaccine hesitancy among Maltese Healthcare workers toward influenza and novel COVID-19 vaccination

Grech

Gauci

Agius

2020

Early Human Development

113

112

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“…To our knowledge, this is the first study to investigate the safety of influenza A (H1N1) 2009 vaccines among patients with COPD, but not the first to examine the safety of the vaccine in the general population [14][15][16][17][18][19][20]. All the patients were of Japanese and mongoloid origin.…”

Section: Discussionmentioning

confidence: 99%

“…However, this result was based on passive surveillance data. The safety of the A (H1N1) 2009 vaccine was not determined [19][20][21]. The Vaccine Adverse Event Reporting System in the United States reported 13 deaths after 46.2 million doses of A (H1N1)2009 vaccine were administered in the United States from October 5 to November 20, 2009.…”

Section: Discussionmentioning

confidence: 99%

Safety of the Influenza A (H1N1)2009 Vaccine in Chronic Obstructive Pulmonary Disease: A Matched Case-Control Study

Yokomichi¹

2012

J Vaccines Vaccin

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Background: The safety of influenza A (H1N1) 2009 among chronic obstructive pulmonary disease (COPD) patients has not been investigated yet. Our objective was to investigate the safety of the A (H1N1) 2009 vaccine, especially for mortality after vaccination. Methods:From October 2009 to March 2010, we collected records from all Japanese hospitals registered in the Japanese Respiratory Society. We conducted a 1:1 matched case-control study. Patients with COPD who died in the study period were determined as case group patients (n=36). Patients with COPD who survived the study period were determined as control group patients (n=36). In the control group selection process, we selected age, sex, period of home oxygen therapy (measure for COPD severity), hospital, and calendar time as matching factors. We then compared the proportion of patients who received the influenza A (H1N1) 2009 vaccine in each group and evaluated the conditional odds ratio.Results: Both the case and control groups had 36 COPD patients, 32 of whom were men. The mean age was 76.6 years (SD=8.6) in the case group and 76.9 years (SD=8.3) in the control group. The mean period of home oxygen therapy in both groups was 1.8. The proportion of patients receiving A (H1N1) 2009 vaccinations was 47.2% in the case group and 63.9% in the control group. The crude conditional odds ratio of mortality in the winter was 0.33 (95% confidence interval: 0.06-1.34) and adjusted conditional odds ratio was 0.37 (95% confidence interval: 0.09-1.52) with no significance. Conclusions:Our study detected no statistically increased risk of mortality after influenza A (H1N1) 2009 vaccination among COPD patients. The results are, however, limited by the small sample size and low statistical power. A similar larger-scale study is needed in the future to confirm our findings.

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“…Assessing causality can be challenging using spontaneous reporting data due to the well-known limitations of these data e.g. limited quality, incomplete data, underreporting, and reporting bias [70][71][72]. The latter is especially relevant for events like death, as this event may much sooner be reported than less serious events, even if coincidental [70].…”

Section: Limitationsmentioning

confidence: 99%

“…limited quality, incomplete data, underreporting, and reporting bias [70][71][72]. The latter is especially relevant for events like death, as this event may much sooner be reported than less serious events, even if coincidental [70]. These are common issues with spontaneous adverse event reporting data and the primary goal of these spontaneous reporting databases is to detect signals and generate hypothesis, rather than confirm potential vaccine event combinations.…”

Section: Limitationsmentioning

confidence: 99%

Fatal outcomes following immunization errors as reported to the EudraVigilance: A case series

Hoeve

Gadroen

Kwa

et al. 2020

Vaccine

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Background: Serious adverse reactions after immunization are rare but do occur. In very rare instances, cases with fatal outcome have been reported. These reports can have a huge impact and even more so when due to an immunization error. The aim of this study is to systematically review immunization errors with fatal outcomes in EudraVigilance. Methods: This was a case-series analysis of Individual Case Safety Reports (ICSRs) reporting immunization errors and a fatal outcome. To determine the level of certainty of a causal association between the immunization errors and fatal outcomes two independent reviewers assessed all ICSRs using the WHO tool ''Causality assessment of an Adverse Event Following Immunization (AEFI)". In accordance with the tool, the ICSRs were classified as consistent, indeterminate, inconsistent/coincidental, or unclassifiable. In addition, we estimated the contribution of reported errors to the fatal outcomes as large, moderate, small, none, or unclassifiable using a classification developed for this study. Results: A total of 154 ICSRs met the inclusion criteria. Vaccines reported most frequently were pneumococcal (33), rabies (27) and influenza vaccines (24). Most frequently reported errors were noncompliance with recommended schedules of immunization (63). The most frequently reported vaccine-error combination was rabies vaccines and non-compliance with a recommended schedule of immunization (23). Twelve cases were classified as consistent with causal association and had a large error contribution. These cases concerned a cluster of six cases reporting incorrect handling of multidose vials containing measles vaccine and six cases reporting administration of live-attenuated vaccines to immunocompromised patients. Discussion: In this study, we showed that fatal outcomes following immunization errors are very rare. Four key issues were the importance of: (1) quality control of multi-dose vaccines, (2) screening patients for immunocompromising factors, (3) education on the importance of adherence, and (4) measures to improve distinction between vaccines and medicines.

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Risk of Fatal Adverse Events after H1N1 Influenza Vaccine: Limitations of Passive Surveillance Data

Cited by 7 publications

References 4 publications

Withdrawn: Vaccine hesitancy among Maltese Healthcare workers toward influenza and novel COVID-19 vaccination

Withdrawn: Vaccine hesitancy among Maltese Healthcare workers toward influenza and novel COVID-19 vaccination

Safety of the Influenza A (H1N1)2009 Vaccine in Chronic Obstructive Pulmonary Disease: A Matched Case-Control Study

Fatal outcomes following immunization errors as reported to the EudraVigilance: A case series

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