A primer in Immunology

Immunology is generally not a student favourite. This is in part because it is probably the most acronym ridden subject in the already acronym overloaded biomedical scientific world, and it has the most obscure new vocabulary to learn. That said the immune system itself is remarkable, and it is a shame that revealing its wonders to the world is frequently so painfully done. It is a subject for another day that University staff are recruited mainly for the research glamour (and cash) they bring to their Departments and that many seem to have little or no formal training in teaching. Do ask the next Medical Student you meet if you doubt this.

Our immune system protects us from the many microbes that wish to infect us. There are around 1,400 that have so far been documented as causing infections in humans. It also has some protective benefit against cancers but this is a spin-off since it didn’t evolve for that purpose.

Broadly our immune is divided into two systems, the innate and the adaptive.

The innate immune system is what keeps us all infection free day-to-day and provides a hugely effective barrier to microbes crossing the skin or gut to get into our blood or tissues. It is a diverse ‘system’ including antiseptic substances in tears, the fact we shed skin scales (and their adherent bugs), the cough reflex; we have protective proteins on our skin and in our blood and we also have cells, phagocytes that eat invading microbes. External damage, heat, trauma etc. triggers an ‘inflammatory’ response in the innate immune system with the well-known features of redness, heat, swelling and pain (rubor, tumor, calor and dolor as described by Celsus). Think of sunburn and you get the basic idea. This response helps amplify the ability of the innate system to clear infection, should it be part of the damage. The innate immune system is remarkably powerful and it is all there is to protect animals other than vertebrates. It is undoubtedly the reason why it is so hard to catch HIV, at least by sexual contact, as the innate defences stop the virus getting in. Its limitation is that it does not change. The response is exactly the same the first and the thousandth time that you meet a damaging stimulus or a dangerous bug.

The adaptive immune system is the icing on the cake for vertebrates and is at its most sophisticated in humans. It is without doubt one reason, along with our complex brains and opposable thumbs, for our success as a species. The adaptive system is just that. Once it has encountered a bug it remembers it and next time the same one arrives, the antibodies and the killer cells which were selected as being the best to defend us when they first met the danger are already primed. They respond faster the second (and subsequent) times and get better and better at their defensive role.

In carrying out their attacks on the repeated attempts at invasion by microbes they recruit some of the innate system too including some of the proteins and hormones that activate defences more generally. It is these, substances such as interferon, that make us feel ill when we have infections like ‘flu. Much of the adaptive immune response takes place in lymph nodes, often inaccurately termed ‘glands’ which occur at junctional bottlenecks such as where the arms and legs join the body, the armpit and groin. If there is an immune response locally they can get swollen which stretches their outer capsule causing discomfort.

Thus it is today after my third rabies vaccination yesterday that my innate system set up the same painful response at the site of injection that it did the first two times. The injection site swelled up and it is now going down.
My adaptive immune system however was, after two previous encounters, on a hair trigger. In the words of Goldfinger to James Bond, my adaptive response has said this is not a first encounter (happenstance), nor is it coincidence (a second encounter) but clearly enemy action (a third). This is perhaps a long-winded and tortuous way of leading up to the fact that today I feel generally unwell and have a swollen painful lump under my arm. I can tell you why though and perhaps it explains to those to whom immunology is a dark art why the same happens to them. There is a mysterious reassurance to knowing what is going on and having a label for it – a diagnosis – something that people often seem to crave more than a cure.

At £42 per shot the rabies vaccine is not cheap, but it is paradoxically encouraging that I feel like this because £126 is peanuts if my adaptive immune system responds to the usually fatal rabies virus this violently – should they ever meet.

Am I qualified?

One thing I didn’t mention is how labyrinthine the registration system to validate your medical qualifications for SA is. Apart from a standard form documenting your qualifications and experience they require notarised versions of every relevant document:- degree certificate, postgraduate qualifications, specialist accreditation, passport etc. They ask for originals but the notary public does photocopies and notarises those. Notarising itself is a nice little earner. In theory each document costs £100 to notarise. Fortunately I managed to get a bulk discount. Intriguingly the wording in the letter from the notary which accompanies all your photocopies – all neatly bound with a red ribbon and a red wax seal – states that the notary has not made any attempt to prove that these documents are genuine, or words to that effect. No room for fraud then.

Notaries public are apparently two a penny in France where lots of documents undergo this form of validation but you have to search quite hard for your local one in the UK. Two witnesses with passports and utility bills have to come and swear that you are who you say you are. On the form the Health Board sends you it says the witnesses signatures can be validated by a Justice of the Peace (free) so I did that. However the form is wrong and surprise surprise it has to be a notary (ching ching). Utility bills don’t include mobile phone bills for some obscure reason, neither can you download another utility bill from the web at the notary’s office because downloads aren’t accepted. Given that every utility and other provider is now giving discounts for paperless online billing then getting hard copies of bills is becoming more and more tricky so this anachronism is going to have to change. Actually it’s rubbish anyway as if you download and print off a PDF of your utility bill before you go to the notary they can’t tell whether it arrived in the post or online.

I thought it would be a good move to have my two witnesses as doctors of African origin, so thank you, Sani and Tumenah.

It is fair to say that they do treat everyone the same. They are obviously more used to recently qualified energetic young things with minimal experience coming over there and I am something of an anomaly having qualified over 30 years ago. Just because two of my referees are knights of the realm also shouldn’t lead me to expect any favoured treatment.

The agency dealing with the application in South Africa scrutinises your draft submission. There are many things which can go wrong, and do, before your application is perfect enough to put in front of the Health Board in SA. So after multiple attempts my documents were submitted some time back. Since then progress has been glacial.



With the encouragement of my grown up children I am starting this blog about my forthcoming trip to spend time in a rural hospital in South Africa. I will be there for just 3 months in a remote part of the Eastern Cape. As yet nothing much to say. One more rabies injection due, one more dose of cholera vaccine (perhaps overcautious I realise), malaria tablets and other useful medications bought (£100+) and an advanced trauma and life support course due before I go. That’s it I guess. It will be good leaving the UK as summer ends and arriving in SA in Spring although the Summer to midwinter transition coming back won’t be as much fun.

OK Rob, Jonny and Gill I have started….