[Vaccine-related adverse reactions in immunocompromised patients and in special situations of a hospital Vaccine Unit]

OBJECTIVE

The aim of the study was to describe the type of vaccines administered in the Vaccine Unit at a reference hospital. Calculate the overall and specific reporting rate of adverse reactions.

METHODS

Retrospective observational study for the period between November 2014 and November 2017, on patients who developed an adverse drug reaction (ADR) after the administration of a vaccine and who were notified to the Spanish Pharmacovigilance System. The variables analyzed were age, sex, risk group, vaccine class, co-administration and type of ADR. A univariate and bivariate analysis was performed. The global and vaccine specific rate of ADR notification was calculated.

RESULTS

A total of 18,123 vaccines were administered, of which 20.7% corresponded to hepatitis B virus vaccine. Fifty-three RAM suspects were reported. In 64.2% of cases only one vaccine was administered. Inactivated vaccines accounted for 88.7% of notifications. The highest number of notifications was generated by the 23 serotypes pneumococcal polysaccharide vaccine. The overall reporting rate was 0.42%. The hexavalent vaccine had the highest reporting rate (2.81%). 49.1% of the ADR were systemic.

CONCLUSIONS

The overall reporting rate was low but higher than that of other authors. Proper reporting of possible adverse post-vaccine reactions is essential to contribute to vaccine safety and to increase public confidence in vaccines.

Optimal duration of first-line chemotherapy for advanced gastric cancer: data from the AGAMENON registry

BACKGROUND

The optimal duration of first-line chemotherapy for patients with advanced gastric cancer is unknown. Diverse clinical trials have proposed different strategies including limited treatment, maintenance of some drugs, or treatment until progression.

METHOD

The sample comprises patients from the AGAMENON multicenter registry without progression after second evaluation of response. The objective was to explore the optimal duration of first-line chemotherapy. A frailty multi-state model was conducted.

RESULTS

415 patients were divided into three strata: discontinuation of platinum and maintenance with fluoropyrimidine until progression (30%, n = 123), complete treatment withdrawal prior to progression (52%, n = 216), and full treatment until progression (18%, n = 76). The hazard of tumor progression decreased by 19% per month with the full treatment regimen. However, we found no evidence that fluoropyrimidine maintenance (hazard ratio [HR] 1.07, confidence interval [CI] 95%, 0.69-1.65) worsened progression-free survival (PFS) with respect to treatment until progression. Predictive factors for PFS were ECOG performance status, ≥ 3 metastatic sites, prior tumor response, and bone metastases. Toxicity grade 3/4 was more common in those who continued the full treatment until progression vs fluoropyrimidine maintenance (16% vs 6%).

CONCLUSION

The longer duration of the full initial regimen exerted a protective effect on the patients of this registry. Platinum discontinuation followed by fluoropyrimidine maintenance yields comparable efficacy to treatment up to PD, with a lower rate of serious adverse events.