Safety surveillance of influenza A(H1N1)v monovalent vaccines during the 2009-2010 mass vaccination campaign in France

Risk Of Urticaria In Geriatric Stroke Patients Who Received Influenza Vaccination: A Retrospective Cohort Study

Objective

Urticaria is a mast cell-related disease caused severe itching and the lifetime prevalence of urticaria is about 20% in general population. Our purpose is to evaluate risk of urticaria in geriatric stroke patients received influenza vaccination (IV).

Methods

In a cohort of 192,728 patients with newly diagnosed stroke aged over 65 years obtained from 23 million people in Taiwan’s National Health Insurance between 2000 and 2008, we identified 9890 stroke patients who received IV and 9890 propensity score-matched stroke patients who did not receive IV. Controlling for immortal time bias, both the IV and non-IV groups were followed for one year. Urticaria events were identified during the follow-up period. We calculated the adjusted rate ratios (RRs) and 95% confidence intervals (CIs) of the one-year risk of urticaria associated with IV.

Results

During the follow-up period of one year, stroke patients with IV had a significantly higher risk of urticaria compared with non-IV stroke patients (RR 1.81, 95% CI 1.47–2.23). An increased risk of urticaria in stroke patients with IV was noted in both sexes, patients 65–84 years of age, patients with comorbid medical conditions, and various time intervals of follow-up. Vaccinated stroke patients with hemorrhage (RR 4.00, 95% CI 1.76–9.10) and those who received intensive care (RR 5.14, 95% CI 2.32–11.4) had a very high risk of urticaria compared with those without IV.

Conclusion

Receiving IV may be associated with an increased risk of urticaria in stroke patients. We could not infer the causality from the current results because of this study’s limitations. Future investigations are needed to evaluate the possible mechanism underlying the association between IV and urticaria.

The PREGVAXGRIP study: a cohort study to assess foetal and neonatal consequences of in utero exposure to vaccination against A(H1N1)v2009 influenza

BACKGROUND

In October 2009, in the context of an A(H1N1)v2009 influenza pandemic, a vaccination campaign was launched in France, in which one of the priority groups was pregnant women, on account of the high risk of developing complications following infection by this virus.

OBJECTIVE

The aim of this multicentric, prospective, observational study was to assess safety and pregnancy outcomes in a cohort of pregnant women when receiving the A(H1N1)v2009 influenza pandemic vaccine.

METHODS

This was a prospective study that followed up pregnant women recruited mainly in vaccination centres and maternity departments. Following the expected delivery date, follow-up data were collected concerning the delivery, the infant, and, if appropriate, the reasons why the pregnancy did not reach its term.

RESULTS

Between 1 November 2009 and 31 March 2010, 2,415 pregnant women were included at the time of vaccination; 97.6 % of women received a vaccine without adjuvant and 2.4 % received an adjuvanted vaccine. Ninety-two (3.9 %) women were vaccinated during the first trimester of pregnancy, 1,090 (46.5 %) during the second trimester, and 1,162 (49.6 %) during the third trimester. One hundred and thirty-three adverse events (5.5 % of women) were reported, of which 12 were unexpected or serious. There were 2,246 (93.0 %) known pregnancy outcomes with 12 spontaneous abortions (0.5 %), 6 stillbirths (0.3 %), and 4 therapeutic abortions (0.2 %). There were 65 neonates with congenital anomalies, among which 31 were major. But only one congenital malformation (1.4 %) was reported for the 92 women vaccinated in their first trimester. Of the women, 93.3 % were delivered full term and 6.7 % preterm. For 96 (4.2 %) neonates, a disorder was reported in the neonatal period and 130 (5.6 %) were transferred to the neonatology department.

CONCLUSIONS

This study suggests that exposure to the A(H1N1)v2009 pandemic influenza vaccine during pregnancy does not increase the risk of adverse pregnancy outcomes. However, because of the relatively small number of women exposed during the first trimester, other studies are needed to exclude an increased risk of malformation.

Immunogenicity and safety of two doses of a non-adjuvanted influenza A H1N1/2009 vaccine in young autoimmune rheumatic diseases patients

Objectives

The aim of this study was to evaluate the immunogenicity and safety of the influenza A H1N1/2009 vaccine in children under 9 years old with autoimmune rheumatic diseases (ARD).

Methods

Thirty-eight ARD patients and 11 healthy children received two doses of non-adjuvanted influenza A/California/7/2009 (H1N1) virus-like vaccine. Subjects were evaluated before and 21 days after vaccination. Seroprotection (SP) and seroconversion (SC) rates, geometric mean titers (GMT) and factor increases (FI) in GMT were calculated.

Results

Mean ages were comparable between patients and controls. Pre-vaccination SP and GMT were similar in patients and controls ( p > 0.05). Three weeks after immunization, SP (81.6% vs. 81.8%, p = 1.0), SC (81.6% vs. 90.9%, p = 0.66), GMT (151.5 vs. 282.1, p = 0.26) and the FI in GMT (16.7 vs. 36.3, p = 0.23) were similar in patients and controls, with both groups achieving an adequate response, according to the European Medicines Agency and Food and Drug Administration standards. Analysis of the possible factors influencing SC showed no difference in demographic data, leukocyte/lymphocyte counts or immunosuppressant use between seroconverted and non-seroconverted patients ( p > 0.05). The vaccine demonstrated a satisfactory safety profile in this population.

Conclusions

Two doses of influenza A H1N1/2009 vaccination induced an effective antibody response and caused adverse events in rare instances, suggesting this vaccine is appropriate and can be recommended for this age group.

First French experience of ADR reporting by patients after a mass immunization campaign with Influenza A (H1N1) pandemic vaccines: a comparison of reports submitted by patients and healthcare professionals

BACKGROUND

Available data concerning the contribution of patient adverse drug reaction (ADR) reporting in practice are scarce. Few studies have compared patients' reports with reports from healthcare professionals (HCPs). During the 2009-10 mass immunization campaign with A (H1N1)v2009 pandemic influenza vaccines, a reinforced pharmacovigilance plan was introduced in France according to European Medicines Agency recommendations. For the first time, patients were offered the opportunity to report suspected ADRs to pandemic vaccines directly to regional pharmacovigilance centres.

OBJECTIVE

The aim of the study was to compare the characteristics of patient and HCP ADR reports in order to assess the qualitative and quantitative contribution of patient reporting to the French Pharmacovigilance System.

METHODS

All spontaneous ADRs registered into the French Pharmacovigilance Database from 21 October 2009 to 15 June 2010, in which either one of the most frequently administered pandemic vaccines (i.e. Panenza® or Pandemrix®) was involved, were analysed. ADRs were classified as 'serious', 'medically serious' and 'non-serious'. This study focused on 'serious' and 'medically serious' ADRs. An ADR was ranked as 'medically serious' when it required medical intervention or hospitalization within less than 24 hours. In each level of seriousness, frequency of 'unlabelled' ADRs, ADRs of 'special interest', imputability scores and category of ADRs according to Medical Dictionary for Regulatory Activitives (MedDRA®) primary System Organ Class were compared between patient and professional reports.

RESULTS

Among the 4746 reports received during the study period, 1006 (21.2%) originated from patients. HCPs reported significantly more 'medically serious' or 'serious' ADRs than patients (15.1% [565/3740] vs 8.4% [85/1006], respectively; p < 0.001). No difference was found in 'unlabelled, serious' ADRs between patients and HCPs (56.5% [n = 13] vs 56.7% [n = 136], respectively).

CONCLUSIONS

In this first French experience of formal patient participation to ADR reporting, patient contribution to the total number of ADRs reached 21.2%. This study revealed no major qualitative difference between patient and HCP reports. ADR profiles reported by patients appeared to be consistent with those from professionals. Further investigations are necessary to assess the intrinsic quality of notification forms coming from non-professional reporters. However, this study is of particular interest in the context of publication of the first governmental decree that will formally integrate patient participation to the current French ADR reporting scheme.

Factors associated with parental acceptance and refusal of pandemic influenza A/H1N1 vaccine in Turkey

The objective of this study was to investigate the parents' attitudes towards and identify the possible factors associated with pandemic H1N1 vaccine uptake that was recommended to children between 6 months and 5 years of age. A questionnaire exploring the attitudes of parents to H1N1 vaccine was given to parents of children 6 through 60 months of age attending to Akdeniz and Gazi University Hospitals' well-child departments between 15 November 2009 and 15 January 2010. The questionnaire included questions on demographic characteristics, parental perception of the severity of the pandemic, the presence of anyone in their environment who suffered from pandemic influenza, their decision on whether or not to vaccinate their child, the factors that influenced them during decision-making process and possible factors that might have influenced the opponents of their decision. Those who accepted to get their children vaccinated got it immediately, free of charge. Out of 611 parents who responded the questionnaire 226 (36.7%) had their children vaccinated. Parental education period of less than 12 years, not being a close relative of a health care worker, not having a relative who suffered from the disease, having a child younger than 36 months, being influenced by the relatives' opinions or from the politicians or from the media all decreased vaccine acceptance. Factors that were most significantly associated with vaccine refusal were thinking that the pandemic was exaggerated (OR 9.44, 95% CI 4.28-20.82) and believing that other preventive measures were more effective than H1N1 vaccine (OR 15.61, 95% CI 7.37-33.08). Lessons learned from influenza H1N1/2009 pandemic may help national authorities, health care providers and media on how to keep the public well informed and find ways of better risk-benefit communication with the parents on vaccines.