Pediatric Safety Evaluation of An AS-Adjuvanted H5N1 Prepandemic Candidate Vaccine in Children Aged 3–9 Years: A Phase II Study

Abstract

Two telephone surveys were conducted during October 3-11 and December 15-17, 2007 targeting people aged 65 and older randomly sampled by the Computer Assisted Telephone Interview (CATI). Questionnaires were developed under the theoretical framework of the health belief model. Among 1,115 effective samples of pre-survey, 512 (45.9%) were successfully followed.512 people of post-survey were representative of pre-survey population because of their comparability of demographic characteristics. 62.6% (698/1,115) expressed their willingness to receive vaccination and 61.0% (312/512) among post-survey samples actually received vaccination. Important factors influencing their willingness were their beneficial belief in vaccination (OR = 19.8, 95% CI = 10.0-39.2), with obstacles of vaccination (OR = 8.0, 95% CI = 5.0-12.7), awareness of disease seriousness (OR = 1.9, 95% CI = 1.2-3.0). The relevant factors for actual vaccination were living with chronic disease (OR = 2.2, 95% CI = 1.1-4.1), fear of contracting influenza (OR = 3.2, 95%CI = 1.8-5.8, fear of health impairment OR = 3.3, 95% CI = 1.7-6.7, fear of adverse effects of vaccination (OR = 0.2, 95% CI = 0.1-0.3) and unawareness of disease threat (OR = 0.5, 95% CI = 0.30.9).The rate of willingness, approximately to the actual rate of vaccination, and the similar attitude and beliefs on influenza vaccination between two survey population demonstrate the difficulty of conducting propaganda for the elderly. However, target-oriented, focusing relevant factors and selecting appropriate media channels would be the solution for the challenge of high vaccination rate of the elderly.

Emulsion-Based Adjuvants for Improved Influenza Vaccines

“…Vaccines containing ASO3 have been evaluated in thousands of individuals. ASO3-H5N1 vaccine has been reported to be safe in both adults and children [36,37]. The vaccine has been reported to be immunogenic, to be dose sparing, and to induce cross-clade immune responses [38,39].…”

A vaccine manufacturer’s approach to address medical needs related to seasonal and pandemic influenza viruses

“…The candidate H5N1 AS03-adjuvanted vaccine did not raise any safety concerns and the reactogenicity profile was considered to be clinically acceptable 52,53…”

“…49 In children aged 3-9 years, the vaccine containing 1AE9 lg HA (A⁄ Vietnam ⁄ 1194 ⁄ 2004) adjuvanted with AS03 demonstrated marked cross-clade immunogenicity. 50 Safety and reactogenicity profiles of PrepandrixÔ In the study by Leroux-Roels et al, 39 the most common adverse event was injection site pain, reported by 90% of subjects receiving the adjuvanted 3AE75 lg HA formulation within 7 days after vaccination. Pain was reported significantly less frequently (38%) in the non-adjuvanted 3AE75 lg group (P < 0AE0001).…”

“…The candidate H5N1 AS03-adjuvanted vaccine did not raise any safety concerns and the reactogenicity profile was considered to be clinically acceptable. 52,53 Overall, no safety concern has been raised in any of our clinical trials using the H5N1 vaccine. The AS03-adjuvanted formulation of the vaccine induced superior immunogenicity and a higher incidence of adverse events, although the vast majority of these adverse events were mild to moderate in intensity and all were transient in nature.…”

“…The AS03-adjuvanted formulation of the vaccine induced superior immunogenicity and a higher incidence of adverse events, although the vast majority of these adverse events were mild to moderate in intensity and all were transient in nature. 39,48,49,[51][52][53] No SAEs related to vaccination with AS03-adjuvanted H5N1 vaccine were reported.…”