Allergic adverse events following immunization: Data from post-marketing surveillance in Apulia region (South of Italy)

Safety of an inactivated enterovirus 71 vaccine administered concurrently with other vaccines among infants aged 6-11 months: An observational study using active surveillance

Vaccine co-administration can efficiently increase vaccination uptake and timely immunization. This study aimed to evaluate the safety of the enterovirus 71 (EV71) vaccine administered alone or concurrently with other vaccines in infants 6-11 months. A total of 3,769 EV71 vaccine doses were administered to children in the active surveillance area, of which 1,909 were administered concurrently with other vaccines and 1,860 doses were administered alone. Active surveillance was conducted to observe adverse events (AEs) within 0-7 and ≥8 days after vaccination and to determine the incidence of reported AEs. The overall AE incidence was 2.12% (95% CI: 1.66%-2.58%), with 1.56% (95% CI:1.00%-2.12%) for the EV71 vaccine alone and 2.67% (95% CI: 1.95%-3.40%) for simultaneous administration of the EV71 vaccine and other vaccines (x 2  = 5.612, p = .018). The solicited local AE incidence was 1.00% (95% CI: 0.55%-1.44%) in the EV71 vaccine co-administration group and 0.59% (95% CI: 0.24%-0.94%) in the EV71 vaccine alone group (x 2  = 1.946, p = .018). The solicited systemic AE incidence was 1.68% (95% CI: 1.10%-2.25%) and 0.86% (95% CI: 0.44%-1.28%) in the EV71 vaccine co-administered and EV71 vaccine alone groups, respectively (x 2  = 4.990, p = .025). No serious vaccine-related AEs were reported. Fever was the most common AE; no difference was observed in the incidence rate of fever between the two groups (x 2  = 3.467, p = .063). Overall, AE incidence following EV71 vaccination alone or concurrently with other vaccines was acceptable; concurrent vaccination did not increase AE risk or severity.

Safety profile of recombinant adjuvanted anti-herpes zoster vaccine (RZV) in high-risk groups: Data from active surveillance program. Puglia (Italy), 2021-23

BACKGROUND

Since 2021 a recombinant adjuvanted anti-Herpes Zoster vaccine(Recombinant Zoster Vaccine, RZV) is offered in Italy to high-risk patients. Few real-life data about RZV safety are available in target populations.

OBJECTIVES

This study investigates Adverse Events Following Immunization(AEFIs), baseline disease flare-ups, and Herpes Zoster (HZ) episodes occurring after RZV administration in a heterogeneous population of fragile patients to design its safety profile.

METHODS

This is a retrospective population-based study. RZV-vaccinated patients at Bari Policlinico General Hospital vaccination clinic from October 1st, 2021, to March 31st, 2023, were enrolled. Subjects were screened for reason of RZV eligibility and baseline chronic pathologies. AEFIs occurred in the first 7-days post-vaccination period were collected, and baseline disease flare-ups and post-vaccination HZ episodes were assessed via a 3-month follow-up.

RESULTS

Five-hundred-thirty-eight patients were included and total of 1,031 doses were administered. Most patients were vaccinated due to ongoing immunosuppressive therapy(54.65 %); onco-hematological and cardiovascular conditions were the most common chronic baseline pathologies. Out of 1,031 follow-ups, 441 AEFI cases were reported(42.7/100). The most common symptoms were injection site pain/itching(35.60/100), asthenia/malaise(11.44/100), and fever (10.09/100). Four serious AEFIs occurred(0.38/100). Older age, male sex, and history of cardiovascular diseases(OR:0.71; 95CI:0.52-0.98; p-value <0.05) were found to decrease AEFIs risk, while endocrine-metabolic illnesses(OR:1.61; 95CI:1.15-2.26; p-value <0.05) increased it. Twelve patients(2.23 %) reported a flare-up/worsening of their baseline chronic condition within the first three months after vaccination(mean interval 31.75 days, range 0-68 days). Patients with rheumatological illnesses had a higher risk of relapse(OR:16.56; 95CI:3.58-76.56; p-value <0.001), while male sex behaved as a protective factor. Twelve patients who completed the vaccination cycle(2.43%) had at least one HZ episode by the long-term follow-up.

CONCLUSIONS

The study demonstrates RZV safety in a significant number of high-risk patients. Hence, RZV should be actively offered as part of tailored vaccination programs to decrease the burden of HZ in fragile populations.

Multivariate Analysis of Adverse Reactions and Recipient Profiles in COVID-19 Booster Vaccinations: A Prospective Cohort Study

BACKGROUND

This study investigated the impact of vaccinated population profiles, vaccine type/interval, and the number of vaccine doses on adverse reactions to receiving a coronavirus disease 2019 (COVID-19) booster vaccination.

METHODS

A survey of adverse reactions was conducted from January 2022 to December 2022 among Osaka University Dental Hospital employees who received their third or fourth doses. The study included 194 third-dose recipients and 131 fourth-dose recipients. Comparisons of the occurrence of adverse reactions between the third- and fourth-dose groups were analyzed via a chi-squared test. The relationships between each adverse reaction occurrence and recipient profiles, vaccine type/interval, and the number of vaccine doses were analyzed via a logistic regression analysis.

RESULTS

No significant differences were found in the occurrence of adverse reactions between the third and fourth doses. Younger recipients often developed injection site reaction, fatigue, chills, fever, arthralgia, headache, diarrhea, and any adverse reactions more often. Females had higher frequencies of fatigue, chills, headache, and nausea compared to males. Recipients without underlying diseases had higher frequencies of fever and nausea than those with underlying diseases.

CONCLUSIONS

Younger recipients and females were at higher risk for adverse reactions to a COVID-19 booster vaccination, while the number of vaccinations, vaccination interval, vaccine type, and cross-vaccination showed no significant associations.