The WHO has identified 42 candidate vaccines in clinical trials, ten of which are in the most advanced "phase 3" stage.
For some diseases, such as measles, infection confers lifelong immunity. For other pathogens, immunity may be fleeting at best.
Globally, over 40 percent of stillbirths occur during labour.
Afghanistan, the Philippines, Indonesia, Nigeria and Pakistan saw "substantial" increases in the number of people strongly disagreeing that vaccines are safe between 2015 and 2019.
Clark said the findings could help governments make decisions on who receives a COVID-19 vaccine first when one becomes available.
More than 5,000 people have died from COVID-19 in Britain, fewer than in Spain, Italy and France.
As of 1900 GMT Monday the virus had killed 36,374 people out of 757,940 cases globally.
The report highlights the threat children face from harmful marketing of fat- and sugar-laden foods, alcohol and tobacco.
The Economist Intelligence Unit's (EIU) Climate Change Resilience Index measured the preparedness of the world's 82 largest economies.