Why does the herd have immunity?

Tech Term Tuesday.  When a significant proportion of a community (or herd) is immune to a contagious disease through prior illness or immunization, the remaining members of that community (such as newborns, the chronically ill, the elderly and those otherwise not immunized) also receive some level of protection. This is because the likelihood of coming in contact with an infected individual has been substantially decreased.

History and Epidemiology of Global Smallpox Eradication. From the training course titled "Smallpox: Disease, Prevention, and Intervention". The CDC and the World Health Organization. Slide 16.

Herd immunity begins to fail when immunization rates in the community fall below critical thresholds and the community is exposed to new members who are infected (such is the case with individuals travelling from international regions with a high incidence of vaccine-preventable illnesses). As a result, the choices of individuals can harm the broader community.

Sources: CDC Online Glossary and Merriam-Webster Medical Dictionary

Learn More: Herd Immunity Animation at The History of Vaccines website

Advertisements

What do you say?

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

  • Preview The Book

    Visit the website for the book III GIFTS.

  • In The News

    The Herald-Sun presented a large feature of III Gifts poems and photographs to kick off National Donate Life Month. It included the articles, A Living Tribute and Love of Arts... providing a comprehensive and personal perspective of organ donation. Cliff Bellamy, Book & Entertainment Editor described the book as "very insightful." Click through the links and be sure to check them out.

%d bloggers like this: