[Polio close to eradication]. / Polio närmar sig utrotning.

Polio close to eradication The WHO Global Polio Eradication Initiative has been highly successful. With a dramatic decrease in polio since it started in 1988, the number of globally reported cases reached a record low of 37 in 2016. This article describes the WHO Endgame Strategic Plan including milestones that have been reached and challenges that have to be overcome in order to reach the goal of polio eradication by 2020. Efforts to strengthen immunizations systems and to detect and interrupt polio virus transmission focus on the three remaining endemic countries, namely Pakistan, Afghanistan and Nigeria. In 2016 the WHO took the first step to withdraw the oral polio vaccine (OPV) by globally shifting from trivalent to bivalent OPV.  The role of the inactivated vaccine (IPV) in the final phase of eradication and in the post-eradication situation is also considered. Certification of eradication and containment of all polio virus by the end of 2020 is a key objective. Legacy planning includes mainstreaming polio functions into ongoing public health programmes.

Functional tradeoffs underpin salinity-driven divergence in microbial community composition.

Bacterial community composition and functional potential change subtly across gradients in the surface ocean. In contrast, while there are significant phylogenetic divergences between communities from freshwater and marine habitats, the underlying mechanisms to this phylogenetic structuring yet remain unknown. We hypothesized that the functional potential of natural bacterial communities is linked to this striking divide between microbiomes. To test this hypothesis, metagenomic sequencing of microbial communities along a 1,800 km transect in the Baltic Sea area, encompassing a continuous natural salinity gradient from limnic to fully marine conditions, was explored. Multivariate statistical analyses showed that salinity is the main determinant of dramatic changes in microbial community composition, but also of large scale changes in core metabolic functions of bacteria. Strikingly, genetically and metabolically different pathways for key metabolic processes, such as respiration, biosynthesis of quinones and isoprenoids, glycolysis and osmolyte transport, were differentially abundant at high and low salinities. These shifts in functional capacities were observed at multiple taxonomic levels and within dominant bacterial phyla, while bacteria, such as SAR11, were able to adapt to the entire salinity gradient. We propose that the large differences in central metabolism required at high and low salinities dictate the striking divide between freshwater and marine microbiomes, and that the ability to inhabit different salinity regimes evolved early during bacterial phylogenetic differentiation. These findings significantly advance our understanding of microbial distributions and stress the need to incorporate salinity in future climate change models that predict increased levels of precipitation and a reduction in salinity.

Nobel Prizes and the emerging virus concept.

The existence of infectious agents smaller than bacteria was demonstrated already during the 1890s. After this discovery it took more than 50 years before a resilient definition of viruses could be given. There were separate developments of knowledge concerning plant viruses, bacterial viruses and animal viruses. In the mid-1930s, Wendell Stanley at the Rockefeller Institute for Medical Research at Princeton described the purification and crystallization of tobacco mosaic virus. The finding of an "infectious protein" led to him receiving a Nobel Prize in Chemistry in 1946. In studies initiated at the end of the 1930s, bacteriophages were used as a model for replicating genes. They led to important insights into the unique characteristics of virus-cell interactions. However, an understanding of the chemical nature of animal virus particles and their mode of replication was slow in coming. Not until the early 1950s did tissue culture techniques become available, which allowed studies also of an extended number of animal viruses. This article discusses the emergence of concepts which eventually allowed a description of viruses. The unique real-time analyses of the state of knowledge provided by the Nobel Prize archives were used in the investigation. These archives remain secret for 50 years. Besides all of the underlying documents of the Prize to Stanley, comprehensive investigations made in the mid 1950s of Seymour E. Cohen, Max Delbrück, Alfred D. Hershey and Salvador D. Luria (the latter three received a Prize in Medicine in 1969) and of André Lwoff (he shared a Prize in Medicine with Francois Jacob and Jaques Monod in 1965) were reviewed. The final phase of the evolution of our understanding of the virus concept closely paralleled the eventual insight into the chemical nature of the genetic material. Understanding the principle nature of barriers to the development of new concepts is of timeless value for fostering and facilitating new discoveries in science.

Yellow fever and Max Theiler: the only Nobel Prize for a virus vaccine.

In 1951, Max Theiler of the Rockefeller Foundation received the Nobel Prize in Physiology or Medicine for his discovery of an effective vaccine against yellow fever--a discovery first reported in the JEM 70 years ago. This was the first, and so far the only, Nobel Prize given for the development of a virus vaccine. Recently released Nobel archives now reveal how the advances in the yellow fever vaccine field were evaluated more than 50 years ago, and how this led to a prize for Max Theiler.

Polio and Nobel prizes: looking back 50 years.

In 1954, John Enders, Thomas Weller, and Frederick Robbins were awarded the Nobel Prize in Physiology or Medicine "for their discovery of the ability of poliomyelitis viruses to grow in cultures of various types of tissue."5370 This discovery provided for the first time opportunities to produce both inactivated and live polio vaccines. By searching previously sealed Nobel Committee archives, we were able to review the deliberations that led to the award. It appears that Sven Gard, who was Professor of Virus Research at the Karolinska Institute and an adjunct member of the Nobel Committee at the time, played a major role in the events leading to the awarding of the Prize. It appears that Gard persuaded the College of Teachers at the Institute to decide not to follow the recommendation by their Nobel Committee to give the Prize to Vincent du Vigneaud. Another peculiar feature of the 1954 Prize is that Weller and Robbins were included based on only two nominations submitted for the first time that year. In his speech at the Nobel Prize ceremony, Gard mentioned the importance of the discovery for the future production of vaccines, but emphasized the implications of this work for growing many different, medically important viruses. We can only speculate on why later nominations highlighting the contributions of scientists such as Jonas Salk, Hilary Koprowski, and Albert Sabin in the development of poliovirus vaccines have not been recognized by a Nobel Prize.