7 research outputs found
DNA Priming for Seasonal Influenza Vaccine: A Phase 1b Double-Blind Randomized Clinical Trial
<div><p>Background</p><p>The efficacy of current influenza vaccines is limited in vulnerable populations. DNA vaccines can be produced rapidly, and may offer a potential strategy to improve vaccine immunogenicity, indicated by studies with H5 influenza DNA vaccine prime followed by inactivated vaccine boost.</p><p>Methods</p><p>Four sites enrolled healthy adults, randomized to receive 2011/12 seasonal influenza DNA vaccine prime (n=65) or phosphate buffered saline (PBS) (n=66) administered intramuscularly with Biojector. All subjects received the 2012/13 seasonal inactivated influenza vaccine, trivalent (IIV3) 36 weeks after the priming injection. Vaccine safety and tolerability was the primary objective and measurement of antibody response by hemagglutination inhibition (HAI) was the secondary objective.</p><p>Results</p><p>The DNA vaccine prime-IIV3 boost regimen was safe and well tolerated. Significant differences in HAI responses between the DNA vaccine prime and the PBS prime groups were not detected in this study.</p><p>Conclusion</p><p>While DNA priming significantly improved the response to a conventional monovalent H5 vaccine in a previous study, it was not effective in adults using seasonal influenza strains, possibly due to pre-existing immunity to the prime, unmatched prime and boost antigens, or the lengthy 36 week boost interval. Careful optimization of the DNA prime-IIV3 boost regimen as related to antigen matching, interval between vaccinations, and pre-existing immune responses to influenza is likely to be needed in further evaluations of this vaccine strategy. In particular, testing this concept in younger age groups with less prior exposure to seasonal influenza strains may be informative.</p><p>Trial Registration</p><p>ClinicalTrials.gov <a href="http://clinicaltrials.gov/ct2/show/NCT01498718" target="_blank">NCT01498718</a></p></div
VRC 701 Consort diagram of subject disposition.
<p>VRC 701 Consort diagram of subject disposition.</p
Influenza strains included in DNA vaccine prime and IIV3 boost.
<p>The trial was conducted at 4 clinical sites in the United States: Center for Vaccine Development, Saint Louis University, Saint Louis, Missouri; Cincinnati Children’s Hospital Medical Center Cincinnati, Ohio; Hope Clinic of the Emory Vaccine Center, Atlanta, Georgia; and Baylor College of Medicine, Houston, Texas. The first subject was screened for recruitment on December 20, 2011, study vaccinations began on January 10, 2012 and study follow-up continued through April 17, 2013.</p><p>Influenza strains included in DNA vaccine prime and IIV3 boost.</p
Frequency of previous seasonal influenza vaccinations.
<p>*All subjects received 2011/2012 IIV3 at least 8 weeks prior to enrollment in the trial.</p><p>Frequency of previous seasonal influenza vaccinations.</p
GMT 4 weeks Post-Boost for Study Groups by Baseline Immune Response: GMT (95% CI).
<p>GMT 4 weeks Post-Boost for Study Groups by Baseline Immune Response: GMT (95% CI).</p
Solicited Reactogencity within 7 Days of Injection.
<p>Note: Subjects are counted once at the maximum severity reported for each symptom.</p><p>Solicited Reactogencity within 7 Days of Injection.</p