95% of all students and 96% of professors and staff are fully vaccinated - according to Harvard administration. Yet, their business school is moving classes online as Covid cases surge.

If you ask me, entirely expected - based on the transmission, viral load and shedding evidence over the last several months. Also, based on the cautious optimism - as Nature.com refers to it - of anyone slightly familiar with the actual experimental design and parameters of clinical trials. Yet, we still have to talk and explain the science of clinical trials to all those "smart" people and "Science-followers" who claim they are "eradicating virus", "protecting others" and "mandating vaccines" calling everyone else "selfish" and "stupid".

First let us clarify what 95% efficacy means. In practical terms, it means if you give placebo to 100 000 people in clinical trials and within 3 month period you detect 5000 cases of symptomatic Covid, you expect only 250 cases of symptomatic Covid if you vaccinate 100 000 people. And that is equal to only 5% of cases of symptomatic Covid in placebo, unvaccinated group aka 95% efficacy. This has been true from day 0 of clinical trials until now and has not changed.

Why do we calculate efficacy this way?

Well, despite "popular belief", the primary goal of vaccination is not eradication of virus nor prevention of transmission, but - protection of the patient from the disease. Eradication of virus and prevention of transmission via so-called herd immunity can occur, and they are wonderful secondary effects when they do, but they are not the primary goal. A reduction in symptoms and hospitalisations are the deciding parameters for vaccine approval, a reduction in transmission is not.

If you are still confused about the difference between infection/transmission and disease, think of it this way; a person who has an active HIV virus can be infectious and transmit the virus to others for 10 years before showing first symptoms of AIDS. An infection and transmission are independent of disease (aka so-called asymptomatic transmission), but disease is dependent on infection.

If you are still confused about how vaccination affects both disease and infection, think of it this way; the primary goal of vaccines is to prevent or reduce the symptoms of the disease. Sometimes, (1) this also results in reduction of infection and transmission, and sometimes (2) this only turns symptomatic patients into asymptomatic patients who can still transmit virus to others.

When it comes to Covid vaccines, initial data from clinical trials suggested that reduction in both symptomatic Covid and under (1) could be true. However, the reason why Nature.com articles called this "cautiously optimistic" is the fact that we had limited data about transmission, viral shedding and viral loads, and historic knowledge that new variants may prove us wrong and result in, under (2).

So, why are people still parroting the "protect others" narrative?

Well, most likely, because they lack basic understanding of what efficacy means. Also, they and their "experts" most certainly lack the ability to re-assess their position based on the actual evidence.

The evidence tells us that if you are at risk, you should only get vaccinated to protect yourself. If you or anyone else claims otherwise, you are just refusing to acknowledge that "the emperor has no clothes".

https://finance.yahoo.com/news/breaking-harvard-business-school-moves-130846644.html