An AIDS vaccine candidate designed
specifically for Africa and manufactured in Germany has been approved for
human testing. Wayne Koff Ph.D., Vice President for Research and Development
of the International AIDS Vaccine Initiative (IAVI), has announced that the
Medicines Control Agency (MCA) of the United Kingdom has approved Phase I
testing of an MVA vaccine based on HIV subtype A, the most common strain in
Kenya and in many other parts of Africa.
The MVA, or modified vaccinia Ankara-strain, vaccine was designed by
Dr. Thomas Hanke at the Medical Research Council Human Immunology Unit in
Oxford and manufactured under contract by Impfstoffwerke Dessau-Tornau, GmbH
(IDT), a pharmaceutical company in Rosslau, Germany. "Producing the required
amounts of high-quality vaccine for this study is a relatively small
contribution to the solution of the AIDS-problem," says Heinz Hofmann,
executive manager of IDT. "A vaccine for Africa developed through advanced
technology in Europe could, however, be a decisive step forward."
The MVA vaccine is the second component of a novel prime-boost vaccination
strategy. The first component, a DNA vaccine, entered Phase I trials in
Oxford, England at the end of August. Pending approvals from the appropriate
Kenyan authorities it is hoped that the DNA vaccine will move into human
trials in Nairobi, Kenya within the next six months. The German-manufactured
MVA vaccine will first be tested in Oxford and then in Nairobi and then the
two components will be tested as a combination in Oxford and in Nairobi.
Both vaccine candidates are the product of a partnership between the
research teams of Professor Andrew McMichael of the Medical Research Council
Human Immunology Unit at Oxford University in the United Kingdom and Professor
J.J. Bwayo of the University of Nairobi in Kenya. The Oxford/Nairobi
Partnership is the first of four vaccine development partnerships funded by
the International AIDS Vaccine Initiative (IAVI), a global scientific
organization dedicated to accelerating the development of AIDS vaccines for
use throughout the world.
According to Professor McMichael, "Preclinical studies with the
combination of DNA + MVA validated the strategy that by combining the two
vaccines, immune responses against the virus are optimized, compared with
vaccinating with either DNA or MVA alone. These studies provided the
rationale for IAVI's decision to fast-track both candidate vaccines into
The rationale for this approach comes from extensive studies of sex
workers in Nairobi. Despite continuous exposure to HIV, a small minority of
these women has resisted infection over many years. "We hope this vaccine
will stimulate the same strong cellular immune response to HIV that we have
seen in these women," said Prof. Bwayo, who is chairman of the Department of
Medical Microbiology at the University of Nairobi.
Bwayo said, "Until now, most AIDS vaccines have been made from strains
circulating in the North, specifically, subtype B. The development of this
vaccine begins to address the great need for vaccines designed specifically
for Africa." He added: "We recognize that vaccine trials on HIV/AIDS present
unique challenges. Any vaccine trials on humans must go through rigorous
safety and ethical protocols. With HIV we are insisting on even higher
standards of safety and ethics. The proposed vaccine is not curative but
preventive. It is inspired by findings by our scientists in Nairobi."