Indonesia's decision in February to withhold bird flu samples from the World Health Organization hindered vaccine research and underscored inequalities in vaccine development and distribution between developing and developed countries. It emphasized that a global partnership is vital for confronting a pandemic threat.

Azizul Haque

Centre National de la Recherche Scientifique, Paris

Dartmouth Medical School, Hanover

The discovery of genes that can initiate reprogramming in fibroblasts is a monumental contribution that may ultimately allow us to redirect an individual's own cells toward therapeutic ends. But direct reprogramming of somatic cells to create pluripotent cells will not obviate the value of creating embryonic stem cells by nuclear transfer, especially given the recent success of this process in primates.

George Daley

Children's Hospital, Boston

I view the sequencing of famous people more as hype than as a scientific milestone; other human genomes were also sequenced this year, but they were not from wealthy or well-known persons. What's exciting is that the recent work with new sequencing methods gives hope that the cost of genome analysis will soon be low enough for all people to benefit from the power of genome-guided individualized medicine.

Richard Wilson

Genome Sequencing Center, Washington University, St.Louis

The premature termination of the Merck's adenovirus-based HIV vaccine clinical trial was a shock that might signal the end of vaccines aimed at inducing T-cell responses without antibody production. The disappointing lack of efficacy is however an important milestone because it will shift the focus of the research community toward avenues with better chances of success.

Rino Rappuoli

Novartis Vaccines, Siena

Dendreon's Provenge (sipuleucel-T), a first generation dendritic cell vaccine, is the first active cancer immunotherapy ever to show early evidence of improved overall survival in a phase 3 trial. The results obtained so far are already promising, as they indicate that clinically effective cancer vaccines are on the horizon.

Gerold Schuler

Universitaetsklinikum Erlangen, Erlangen

Genome-wide association studies published over the past year identified over 50 genetic contributors to a wide variety of common diseases. Although we haven't yet had time to figure out what these new factors tell us about the biology of disease, 2007 will be remembered as the year in which the logjam preventing the discovery of genes associated with common diseases was finally broken.

David Altshuler

Massachusetts General Hospital, Boston

Credit: Sources: UNAIDS, WHO, MEASURE Demographic and Health Surveys, World Bank