On Twitter, British scientist Dr Michael Yeadon just gave a brief recap of some basic concepts regarding viral infections and immunity. Here’s the unroll:

Sometimes it’s useful to revisit basic concepts. We appear to have forgotten that immunity after viral infection is the rule, not the exception.

“In this chapter, we highlight the principal means by which the host achieves immunity following infection by viruses”.

“Table 27.1 presents an overview”.

“In humans, viral infections are rarely lethal, even if they are highly cytolytic to individual cells. Mortality commonly occurs when viruses jump species (eg. Ebola or HIV), when virus undergoes major antigenic change (i.e., influenza) or when host immunity is compromised”.

“Having entered the body, however, viruses encounter numerous innate defenses and activate the components of adaptive immunity. The latter usually assures that clinical disease, if not infection, will not become evident”.

“Viral infection induces an extensive array of defense mechanisms in the host. Innate defenses come into play to block or inhibit initial infection, to protect cells from infection, or to eliminate virus-infected cells, and occur well before the onset of adaptive immunity”.

Key Concepts: Principles of Antiviral Immunity
-Many human viral infections are successfully controlled by the immune system

-Certain emerging viruses may overwhelm the immune system and cause severe morbidity and mortality

-Other viruses have developed mechanisms to overwhelm or evade the immune system and persist

-Individuals with defects in innate or adaptive immunity demonstrate more severe viral infections

T-cell immunity is more important for control than antibody with many viral infections

-Antibody is important to minimize reinfection, particularly at mucosal sites

-Immune memory is often sufficient to prevent secondary disease, though not in all viral infection

Now this is basic stuff we’ve known for years. Especially the role of T-cells. This is a text book…

….that any undergraduate student might read. So when I hear numerous scientists & medics wringing their hands over how we’ll handle a common & garden coronavirus, I’m genuinely perplexed. “Like the last few, the endemic ones I was taught about, perhaps?” seems a good answer.

And this is why I’ve been forthright. I’ve not been making Nostradamus like predictions, just reading an undergraduate textbook.
Don’t let pseudo people fool you. It’s really not that special a virus; many of us had cross immunity to it before it arrived; very few are made…

…notably ill by it; I regret that those of advanced years, already beset usually by two life-limiting chronic illnesses were more likely to become seriously ill & a very small number died. It’s always been so at the end of life, as this chapter mentioned, when immune competence

…is reduced.

When you hear people setting way too much store about how long antibodies circulate, please know they’re mistaken. That’s not how immunity to most viruses is manifest. It’s mostly T-cells, as many of us have said for months.

Originally tweeted by Yardley Yeadon (@MichaelYeadon3) on October 27, 2020.