A:-  I think the biggest challenges for health systems are: First, getting enough money for primary healthcare and basic infrastructure- this means continuing the political fight for sufficient investment in health services around the world and pushing the needle towards accessible and high quality universal health coverage. Second, the combination of an ageing population, urbanisation, and powerful industries pushing unhealthy products around the world has led to rising chronic disease. Even relatively young people are suffering from chronic diseases such as cancer, diabetes, heart disease, and high blood pressure. And preventing this burden is difficult for the health system broadly given that the main drivers are smoking, alcohol misuse, sedentary lifestyle and overweight/obesity. Third, drug-resistant infections are a rising, and terrifying, threat in which our usual drugs to treat people during surgeries, birth, or those with TB and other infectious diseases don’t work anymore- how can health systems cope with both not enough antibiotics for certain populations, such as children suffering from pneumonia, combined with the antibiotic overuse in other populations. 
But I also see big opportunities in the years ahead: we are seeing leadership at the global level from the heads of the World Health Organisation, the World Bank, the Global Fund, the Gates Foundation and Wellcome Trust recognising that health systems are a crucial priority and must have regular and robust support.  We are seeing head of government from across the world recognising the importance of health systems in order to prevent pandemics, reduce drug-resistance infections, and provide life-saving care to women and newborns during childbirth. Health systems have been linked to national economic productivity, security as well as human rights rationale. And finally, there is rising citizen engagement in healthcare- from the UK, to the US to India and Senegal- ensuring that healthcare is an important electoral issue and that politicians push beyond rhetoric to real change on the ground.