Thread: herd immunity

A lot of people going to think that the concept of "herd immunity" is a bad thing, but it isn’t. It depends on HOW it is achieved. Unfortunately, many aren’t educated on the crucial differences between how "herd immunity" is gained.

The basic concept of herd immunity is breaking the chain of infection through enough of the population (herd) becoming immune. This stops an infection spreading to the vulnerable (i.e those elderly, very young, or with weaker immune systems including cancer patients.)

Vaccines achieve this by introducing an inert (non-functional) or dead version of a virus. The body can still learn to recognise it and develop an immunity (by creating memory cells recognising certain proteins and markers.) Herd immunity is gained, but with little risk.

The alleged approach previously discussed around Covid-19 looked at providing herd immunity but without an inert or dead form. Yes, the result would eventually be an immune population, but the disease would kill many. The idea may have been a 'controlled' spread.

Introducing a "wild type" virus as the inoculation agent could only work if a number of conditions were fulfilled (including):

1) the virus was non-deadly for all or the vast majority
2) those at risk were protected and isolated
3) the population could be modeled and predicted

The difficulty here is that this virus, although majoratively nonfatal, has a high mortality in high-risk groups and spreads well. Those at high risk were not protected (either due to late responses, the intransigence of others or their own will,) and that the UK people..

are, as can be surmised through psychology, unable to muster a safe response based on their own volition alone (which, is not to assign moral blame, it is part of being human that we can't be perfect.) This is true of most populations.

Spread toward herd immunity using a highly transmissable wild type virus with a high mortality in certain groups within a complex heterogeneous and highly interconnected population would never work as it would only gain a herd immunity at significant cost to life.

Or arguably, not gain a working version of herd immunity that could ever be accepted at all. Herd immunity happens all the time in the natural world, but in humans we tend to vaccinate against even mild viruses because they can be deadly in certain groups anyway.

Inoculation using a nontransmissable and inert/dead virus in a controlled way within the population would without the death profile. This is what a vaccine is, and why research is underway for COVID 19. So let's use an example to show how effective different approaches are.

Measles is a virus that is extremely transmissible. Before 1963, it spread naturally and in epidemics, every 2-3 years, caused up to 2.6 million deaths yearly. Vaccination began in 1963. Today, there are 140,000 deaths a year. Vaccines saved millions of lives.

Here the difference in approaches is very clear. Before 1963, any herd immunity was gained only through exposure to the wild type virus and huge numbers of deaths. After 1963, exposure was by vaccine. Death rates plummeted (but not to 0, as not everyone can or allows vaccines)

The crucial thing here is that "herd immunity" is not a bad thing, its actually an incredibly good thing and saves lives (those at risk) if achieved the right way (with a vaccine.) But achieving it through a wild type virus is very unlikely to ever be done safely.

So why take the time to explain? There will be a time after covid 19. And vaccines will be important. And those googling vaccines will read about "herd immunity" and, due to a lack of understanding and poor use of the word by politicians, may avoid treatments that save lives.

Furthermore, certain interest groups (i.e those against vaccination) may use it to support their agenda. These people, even if they are genuinely concerned, often spout dangerous nonsense and put lives at risk (see why measles is still going.)

Much of the science here is simplified, and not all avenues are explored. This is just a simple explanation. I urge you to do your own research too, and here is a good place to start

https://vk.ovg.ox.ac.uk/vk/herd-immunity

In time, herd immunity will be essential for battling COVID-19, but through the vaccine route. I want to be very clear on this incase the message is lost. At the moment, the current approach is mitigating the spread and allowing hospitals the ability to respond.

For now, I urge you to continue with social distancing and isolation under current government guidance:

https://www.gov.uk/coronavirus 

Please share if you found this helpful.

*note, a previous version of this thread was deleted as I wished to simplify on a few points and expand on others. I am more than happy to be corrected on any points, or for those more expert to add useful information. We are all in this together. I wish you all the best.

Oh, and please #retweet