Herd Immunity & Covid-19

What is herd immunity?

The basic idea is that a group (the “herd”) can avoid exposure to a disease by ensuring that enough people are immune so that no sustained chains of transmission can be established. This protects an entire population, especially those who are too young or too sick to be vaccinated.
 Herd immunity is what happens when enough people are immune to a disease (in this case, COVID-19) for the chains of transmission to be broken. As more people become immune, infected people are less able to pass on the disease, and the spread of the disease slows down. This provides an indirect form of protection for those who are not immune.


Usually, individuals become immune through vaccination. But there isn’t yet a vaccine for coronavirus, so herd immunity could only currently be achieved if enough people contract the disease and recover, developing an immunity to it in the process.

 

Comments

Post a Comment

Popular posts from this blog

Covid-19 Surveillance Doesn’t Have To Be Creepy!

Image
The rigorous use of contact tracing, across digital and physical realms, has been credited with helping limit the spread of covid-19 in a number of places, notably Singapore, Taiwan, and South Korea, as well as  India.  As a methodology, it has a long history of use against diseases from SARS and AIDS to typhoid and the 1918-19 influenza pandemic.  In its current instantiations—such as the  mobile-phone app  that South Koreans exposed to the virus must download so they can be monitored during self-quarantine—it has raised new concerns about surveillance and privacy, and about the trade-offs between health, community well-being, and individual rights. It is a lot to contemplate. Imagine doing contact tracing on yourself.  Do you know where you were yesterday, and with whom?  What you were doing? How about a week ago?  Two weeks ago?  How would you track back?  Your calendar?  Your in-box?  Your credit card receipts or digital wallet?  Facebook?  Goog
Read more

To Mask or Not To Mask Covid-19

Image
  As per Centers for Disease Control and Prevention (CDC) & World Health Organization (WHO) , masks for healthy people aren’t necessary, as long as they practice   social distancing   and stay at least six feet away from each other.  The agencies have maintained that the virus is transmitted by either direct contact with an infected person, fomites—an infected surface like a door handle—or from droplets that are produced when someone coughs or sneezes.  But there’s mounting evidence that transmission may occur via aerosols, or viral particles produced during exhalation by way of talking, breathing, singing, and even outdoor exercise. And, some experts and critics of the new CDC guidelines say, there’s   little evidence   that cloth masks offer much protection from that terrifying possibility.   45 of the 60 members of a   choir group   in Washington—none of whom say they shook hands or had physical contact with the other members—tested positive for the novel coronavirus. 
Read more

Nirvana: Australia’s Approach to Covid-19

Image
Australia’s Approach Australia’s results have come despite less stringent restrictions. It has allowed more industries to continue operating, such as construction, and consumers can still get a haircut or buy a takeaway meal, keeping many workers on lower incomes employed. A notice for takeaway and delivery sits on a chair outside a restaurant in Canberra. Photographer: Mark Graham/Bloomberg “Australia is doing better than New Zealand without going to that extreme,” said Peter Collignon, an infectious diseases physician at Canberra Hospital who advises the Australian government. Collignon questions whether New Zealand’s eradication strategy is realistic. “The reality is this virus is everywhere, it’s all around the world,” he said. “So even if you’re successful for a short period of time, how long do you do this for? Six months? Two years? Invariably, you’re going to get the virus re-introduced.” One concern is the phenome
Read more