Sunday, October 26, 2014

Vaccine for Ebola: will it help?

"Several hundred thousand" doses of Ebola vaccine may be available by mid 2015.

This is a very good development.

But how big will the problem be by June 2015?

Take a look at the useful interactive graph here.

It shows 4,366 cases in total in Liberia, Guinea and Sierra Leone on Sept 7th.
It shows 8,973 cases on Oct 12th - a doubling over 4 weeks.
If we keep to a 4 week doubling rate, by June 2015, when we will have a few hundred vaccines, there will be 4,470,784 cases. That is four and a half (4.5) million cases. Approximately the population of Liberia, the smallest of the three countries. One in five (1:5) of the total population of the three countries.

It may take a month for several hundred thousand health staff to actually become immune from their vaccinations, by which time there will be nearly 9 million cases.

Such is the nature of exponential series.

Of course, it may not be this bad. The virus might miraculously mutate and lose its virulence. Or we could get on top of the epidemic by means of "sensitisation" - education of the people about contact and hygeine. The international community might pull itself together, and start responding with military-level inputs of personnell and materiel, as the generals would say.

Equally, it could get worse. Hysteria and paranoia could spread, resistance to education could become the norm, religious fanaticism could spread, civil war could break out and mass population movements, attempting to flee the infected area, could result.

I am not trying to frighten, only trying to help us understand the nature of doubling series.

If you need a little light relief at this stage, take a look at this video from the excellent Emeritus Professor of Physics, Al Bartlett, who says "The greatest shortcoming of the Human Race is the Inability to understand the Exponential function".

So why am I saying this if not to frighten?

It is to draw attention to this post, which points out that there are several common, cheap drugs available which (if used as part of excellent medical and nursing regime with skilled barrier nursing and a major effort to rehydrate patients) could and should, no, must, be tried in West Africa, in an effort to improve the recovery rate from Ebola. They may or may not work. If they do not work, we have lost nothing. If they do work, alone, or in some kind of combination, we could win the war.

Because the more people recover, the more people will be able to recover, because we can use convalescent serum from survivors to treat patients, and then even more of them will recover. And survivors can work in nursing people and burying bodies safely, because they are to some extent, probably a high extent, immune. Morale will change. Science will be held in esteem. And maybe, just maybe, people will begin to understand what is meant by exponential function.

In other words, it is possible to beat this disease. But to do so we have to try every known trick that presents itself to us. Including looking earnestly at ways of modulating the cytokine storm of Ebola Virus Disease.

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