This review paper explores documented episodes of malaria resurgence worldwide, and assesses their association with malaria control programmes, a higher risk of disease transmission and drug resistance. It identifies 75 instances of resurgence in 61 countries over a period of 70 years, with the vast majority related to weakening control programmes, usually due to limited resources. This suggests that gains in malaria control can be lost rapidly if support is not sustained. The authors argue that finding ways to sustain funding for control programmes is crucial, and that there is an urgent need to develop practical solutions to operational and technical threats to their success.

This special issue of the journal Philosophical Transactions of the Royal Society B: Biological Science explores how vaccines can fulfil their full potential for addressing global health challenges. It charts the progress to date, reviewing successes as well as challenges in the development and distribution of both human and veterinary vaccines.

The articles describe how vaccines can help mitigate and treat the world's major infectious diseases such as malaria, tuberculosis and HIV/AIDS, as well as chronic diseases, such as cancer. They explore vaccine policy and financing, ways to accelerate the development of new vaccines, issues surrounding public acceptance, and the logistics of getting vaccines to where they are needed. Also discussed is the use of vaccines to treat diseases in livestock — making an important link between health interventions, agricultural output and economic consequences.

The papers in this issue were presented at the meeting, 'New vaccines for global health', held at the Royal Society in London, United Kingdom, in November 2010.

This series of articles considers the questions and conflicts surrounding the use of patent pools for antiretroviral (ARV) treatments for HIV/AIDS.

It provides background to the debate, considers individual proposals including the UNITAID patent pool, and offers regional perspectives on the suitability of patent pools to Africa, China and India.

This discussion paper describes the links between global climate change and ecosystem and animal health that researchers generally agree on and the impacts that, while less certain, are still likely. The author highlights gaps in current knowledge, emphasising the need for better disease surveillance and more localised climatological and ecological data.

This journal article, written by three researchers in Trinidad and Tobago, looks at malaria in the Caribbean. It asks why there are still outbreaks — including a big one in Jamaica in 2006/2007 — when the disease was allegedly eliminated in the late 1950s. The authors review malaria and vector data from across the Caribbean, summarising the pattern of imported cases as well as indigenous ones.

They identify three essential conditions for malaria transmission: presence of the vector, imported organisms and susceptible human hosts — all of which the authors show still exist across the Caribbean.

The authors suggest specific actions for regional policymakers to combat malaria. These include enhancing vector control skills, strengthening surveillance with new technologies, upgrading malaria therapy, increasing prevention strategies such as bed nets and raising public awareness of malaria. They emphasise that the role of climate change must be considered too, saying that rising temperatures could lead to new malaria vectors entering and colonising Caribbean islands and transmitting malaria on a major scale. But the authors are also careful to point out that the link to climate change is uncertain and remains contested in scientific circles.

Paul Reiter, a researcher on insects and infectious disease at the Institut Pasteur in France, is not convinced that climate change will cause a rise in malaria in tropical regions. In this opinionated review he sets out to dispel widely held "common misconceptions" about the effect of climate variability on future transmission.

To do so, he examines the history of malaria. He finds that in the past, contrary to expectations, climate has often not affected the transmission of the malaria parasite. Researchers claim that the Anopheles mosquito that carries the parasite cannot survive extreme temperatures, yet Reiter cites examples of the mosquito finding ways to adapt. In Sudan, for example, they can survive temperatures of over 55 degrees Celsius by hiding in buildings in daytime and only feeding after midnight.

Reiter's main disagreement with prediction models is that they only look at how one climate variable, temperature, is likely to interact with mosquito populations. Temperature, rainfall and humidity are interconnected and cannot be analysed separately, he says. The ecology of mosquitoes and humans is too complex to predict future malaria prevalence and incidence from temperature alone, he adds.

This paper, published in the New England Journal of Medicine, examines how the Internet can help monitor, prevent and control emerging diseases. The authors argue that the emergence of influenza A(H1N1), or 'swine flu', in April 2009 shows the value web-based information holds for early disease monitoring.

Informal internet channels such as blogs, chat rooms and search engine request analyses can help identify outbreaks more quickly, prevent governments suppressing information and facilitate public health responses. Google and Yahoo data searches can be used to generate epidemic curves that show the number of new infections plotted against time, and are comparable to those derived from traditional influenza surveillance methods.

The Internet also connects experts — through wikis and social networks — to quickly disseminate reports and responses. There is also great potential from public information.

The authors give examples of approaches being taken to monitor infectious diseases, including swine flu, and highlight some of the online resources available, including Google Flu Trends, HealthMap and ProMED.

This feature, published by The Lancet, discusses the world's capacity to cope with a A(H1N1) influenza, or 'swine flu', pandemic. The author outlines some of the progress made in pandemic preparedness since severe acute respiratory syndrome (SARS) and H5N1 influenza (bird flu) hit the world a few years ago, but points out that many countries' plans are flawed.

Many countries in the Asia–Pacific focus on early containment of disease and "social distancing", a strategy particularly important for developing countries as many lack access to antiviral drugs and vaccines. But, on the other hand, countries that focus on surveillance end up with problems if the virus becomes pandemic.

Scientists are struggling to predict what the likely health impact of a pandemic will be because influenza viruses can become more dangerous as they mutate. And epidemiologists are trying to assess which groups of people are most vulnerable and why some people have more severe symptoms than others.

This series of commentaries and research articles — published by The Lancet, the Peking University Health Sciences Centre and the China Medical Board — addresses China's major health challenges, strategies and future. It has been produced by a group of 63 scientists from 10 countries with Chinese scientists making up two-thirds of the authors.

The research papers give scientific evidence on key health issues including the emergence and control of both infectious and chronic non-infectious diseases in China as well as the performance of China's healthcare system.

Authors of the series' commentaries further discuss a range of topical issues affecting China's health system, including the state of biomedical science and technology (see 'Progress in Chinese biomedicine a massive challenge'), medical research ethics, the lessons learnt from China's schistosomiasis control programme and the challenges the country faces in controlling HIV/AIDS.