Pneumonia is the commonest cause of childhood death throughout the world, especially in low and middle income countries. The pneumococcal conjugate vaccine (PCV) has been available for 19 years, but there are still many outstanding issues in its use: how do we measure the impact of this vaccine when the causes of pneumonia are many; how do we monitor serotype replacement in the post-PCV era; how do we measure herd protection; and how many doses of the vaccine are really needed for optimal protection?

June 5, 2019.