This article is more than 5 years old. Information may no longer be current.
Older H5N1 vaccine may prime for antibody response to newer vaccine
Belshe RB. J Infect Dis. 2011; 203:666-673.
Click Here to Manage Email Alerts
Previous H5N1 vaccine may prepare patients for newer vaccines more closely matching the current flu strain, according to new findings published in the Journal of Infectious Diseases.
Current US national stockpile of H5N1 vaccine includes the antigen from the A/Vietnam/1203/2004 strain. However, recent H5N1 has been caused by antigenically divergent viruses, including the A/Indonesia/05/2005 strain, the researchers wrote.
Robert B. Belshe, MD, of the division of infectious diseases and immunology at the Saint Louise University School of Medicine, and colleagues set out to assess the significance of prepping with the older A/Vietnam/04 strain followed by a boost with the newer A/Indonesia/05 strain in 491 healthy adults aged between 18 and 49 years.
Nine different accelerated vaccination schedules were assessed to determine the minimum time needed between priming and boosting.
Compared with a second vaccine administered after 1 month, a second vaccine administered after 6 months led to improvements in heterologous response rate. Moreover, vaccination with the A/Vietnam/04 vaccine primed for heterologous boost when followed by A/Indonesia/05 vaccine (Sanofi Pasteur).
Two 90-mcg doses were required to induce antibody titers of 1:10 ratio in most adults. Accelerated schedules were immunogenic, and antibody developed after vaccinations on days zero and 7, zero and 14, and zero and 28. The day zero and 7 schedule induced lower titers than those induced with other schedules, according to the researchers.
“The results of the present study confirm the usefulness of vaccination with an H5N1 strain that is antigenetically out of date,” they wrote.
 |
Follow InfectiousDiseaseNews.com on Twitter. |