Clive Myrie visits the Royal London Hospital as experts speak of "light at the end of the tunnel".
By Joseph Lee
By Jim Reed
By Nia Cerys
By Graeme Esson & Ruth Iredje
BBC Scotland website
In a group of remote islands in the Democratic Republic of Congo, hundreds of children have been missing out on vaccinations against diseases such as measles and hepatitis.
By Ben Godfrey
Correspondent, BBC Midlands Today
BBC Reality Check answers your vaccine concerns - from pregnancy fears to production speed.
By Becky Morton
By Michelle Roberts
Health editor, BBC News online
By Dulcie Lee & Jennifer McKiernan
By Lauren Turner