BBC News - WorldBBC News - World Immunisation: Why we do it and how 'herd immunity' worksJun 19th 2019, 04:00 This is how vaccines work, why they're important and what the phrase "herd immunity" actually means. You are receiving this email because you subscribed to this feed at blogtrottr.com. By using Blogtrottr, you agree to our policies, terms and conditions. If you no longer wish to receive these emails, you can unsubscribe from this feed, or manage all your subscriptions.
