The West Bengal government hasasked the heads of all hospitals to ensure that immunisation programmes against vaccine-preventable diseases continue in full steam amid the Covid-19 outbreak.Immunisation should go on during COVID-19 outbreak to protect children and pregnant women from 'vaccine-preventable diseases' (VPD), the health and family welfare department said in a notification.It was addressed to the superintendents of all medical colleges and hospitals and the chief medical officer of health of all districts.Copy of the notification issued on May 6 was made available on Saturday.