What are the challenges facing the development of effective vaccines against pathogens with hyper variable genome sequences?

“What is the point in constantly making new vaccines against the same infectious diseases?”

To answer this question, one must ask: ‘what makes for an effective vaccine?’

To explain this, it is important to recognise that a vaccine is simply an inactive form of a pathogen – the bacterium or virus which causes the disease – and the introduction of this vaccine containing the pathogen stimulates an immune response; which helps fight against the disease. At first glance, it seems an atrocious plan to purposefully sicken us, but the vaccination unsurprisingly, in actual fact, can introduce antibodies, as in passive immunity. Alternatively, they can stimulate the production of them from the individuals own immune system, in ‘active immunity’. One can easily recognise the importance of the antibodies in helping us from becoming bed-ridden or more seriously, they can save us from potentially, the verge of the ominous hazard that is, death.

Although, these antibodies work such that they each have unique binding sites, receptor-like, and the pathogen has ‘antigens’, which almost stick-out and form an identity for the pathogen. For an antibody to be work, its binding site must be of a complementary shape to the antigen, and thus they form an antibody-antigen complex. After forming this ‘complex’ by attaching to antigens, they destroy them, though the means by which they carry out this termination does vary.

However, this doesn’t address the question concerning why we need to make new vaccines for the same diseases. Thus, we need to consider antigenic variability, which is where pathogens essentially change their identity deeming them unrecognisable. This change was the change of antigens on the surface of the pathogen. The antigen no longer corresponded to the aforementioned antibodies, and the ‘complex’ could no longer be formed; thus an immune response would never arise. So, it can be established that a troublesome problem is the changing nature to some pathogens and their antigens, such as the influenza virus. Even more worrying would be the finding of a hyper variable sequence, found in the genome, which run in the nucleotides. Nucleotides are chemicals consisting of an organic base, sugar and a phosphate, and are the basic units of which the nucleic acids DNA and RNA are made. The hyper variable sequence would particularly raise concerns because they have a high rate of variation, though the rate of variation differs from one type to the next. Nonetheless, this stipulates that to form an effective measure against these sequences would also require a vaccine which is as ever varying as the pathogens in question.

Unfortunately, such a vaccine is not yet possible, at least now, within the current progress of research. There are many scientific challenges such as the variation which results in the ill-fated truth that an effective vaccine needs to be able to launch an all-encompassing response to all of the diverse strains of a pathogen with a hyper variable genome sequence. An insufficient knowledge about required immunity means that researchers face uncertainty about the parameters for ample immunity against both infection and disease, and so under current scientific knowledge, are simply unable to find a solution.

This lack of scientific knowledge isn’t helped by the social challenges which arrive in the form of ethical concerns surrounding the nature of human subject trials. It is important to acknowledge that though primate studies and computer models can be useful, they by no means provide as detailed a picture as human subject trials can. Nonetheless, in spite of the advantages, the complications appear, and one reason for the difficulties in carrying out human trials could be the volunteers being entitled to a host of treatments, not the vaccinations alone. They are to be made clear of possible adverse effects which the testing vaccination may have, and they are also to be told of the perils of seropositivity from immunisation. I am surprised to inform you that I had paid enough attention to tell you that seropositivity is merely a rather fancy word for one showing a high level of antibody. Such formalities hinder the progress of trials and consequently, the development of vaccines.

Vaccines have changed countless lives and inevitably will continue to do so in a world of advancing science. New opportunities will surface and many hurdles will be overcome; as has happened before in the past. Nonetheless, in the future, the current scientific challenges need to be overwhelmed and the development of vaccinations needs to include the production of vaccines which solve the impediments raised by the hyper variable genome sequence.

A short introduction

Hello readers,

I am a new Valuemed blogger hoping to contribute to this site as ‘mLukon’.

An aspiring doctor wanting to read medicine at university, I am going to apply for medical school this October. I am currently undertaking my A-Levels at Sixth Form, all of which are thoroughly engaging.

I became interested in writing medical-related posts for ‘Valuemed’ after an intriguing summer neurosurgery placement sparked an interest in the brain and degenerative neurological disorders. Through the placement, I became familiar with research papers and so, I would now like to take to ‘Valuemed’ to write a few of my own articles which concern areas of medicine and healthcare that I am fascinated by.

I hope to write interesting and thought-provoking articles soon and would appreciate any feedback and discussion on my blogs.

Hi everyone !

As a prospective medical student looking at 2014 entry, I recently decided to write for the Valuemed blog to widen my medical knowledge (to help me earn a place at medical school) and this will be my first ever post!

I’m currently studying for my AS levels (Chemistry, Biology, Physics, Maths and Geography) at sixth form and have wanted to study medicine for as long as I can remember – I’m often asked why I want to, and the truth is that there is no easy answer… Of course, the structure of the medical course includes a lot of science (which I enjoy) and you will probably spend the rest of your working life learning about new treatments and technologies – I love the idea of having so much variety in a job! It’s a challenging career and I have never been one to turn away from a difficult or stressful situation. I like meeting new people and last but not least, being able to make an active difference in someone’s life appeals to me. Chances are that I won’t discover a new miracle drug or create a life saving vaccination for HIV, but being able to make a positive difference in someone’s life on a daily basis is really what draws me to the career. People often ask me if I want to go into medicine for the money, and honestly, no – I don’t. Without a doubt, it’s a difficult career option – it’s a competitve degree to get into, I’ll be in full-time education for at least 5 years after school – not to mention having debt up to my eyeballs!, the stress, the emotional strain and the frustration when you are unable to help someone… And so, to cut a long story short, if I were in it for the money, I would find something else. But for me, the pros of studying medicine cannot be compared to anything else!

I’ve been involved with St John Ambulance for over 5 years now, and am currently a volunteer at a hospital. Following some work experience, I’ve become quite interested in radiology and ophthalmology as well as surgery (although I have no experience of this yet…). Over the next two years (which will probably fly by!), I hope to expand my knowledge as well as hopefully blog about what I do know.

Goodbye for now,


A new guest blogger saying hello

Hey there! 🙂

I am a 17 year-old A-Level student, currently studying biology, chemistry, mathematics and religious studies. My A-Level choices strongly reflect my desire to study medicine at university, as I have always had a curiosity about what makes the human body work in the way which it does.

I have opted to write for this blog so that I am able to talk about such things which attract and excite me in the medical world and to also use as an aid for me to further understand what I learn within my A-Level studies.

In medicine, the field which interests me the most is cardiology; the study of the disorders and abnormalities of the heart, as well as cardiac surgery. The overall physiology of the heart is very interesting and I crave to learn much more about it! The heart is essentially what keeps the human body alive, beating at approximately 100, 000 times in a day. Despite the strenuous effort it is put under, this impeccable organ being approximately the size of a human fist, it does not tire and continues to pump hundreds of gallons of blood throughout the body per day.

Rather than adult cardiology, I am more appealed by paediatric cardiology. Most children who suffer from cardiac problems, are usually treated incredibly well by paediatricians and nurses and go onto lead perfectly normal lives. However, those who are too ill and too weak to battle on their own, it is their bravery and courage that I admire. When I did my work experience placement at the local hospital in the paediatrics department, there were a handful of patients suffering from both minor and major cardiac problems. Despite the challenges faced by both the staff and the patients, neither of them gave up. I witnessed the physical and psychological stresses faced by the doctors and children on a daily basis, and also the reward and satisfaction felt by both parties when the result was a success. During my time at the hospital, I learned the importance of a caring bedside manner, the ability to console the weak with kindness whilst remaining professional at all times, as well as the crucial role of empathy.

I have also done some other work experience in various care settings and hope to embark upon many more!

An introduction

Hi I am a new blogger to this site and will be known as medschool2013.

 I am currently studying for my A-Levels and a prospective medical student applying in October 2012. I have a huge passion for medicine with particular interests currently being in the branch of cardiology. This interest was ignited during my work experience placement shadowing doctors in a cardiology department. Since then i have pursued my interest by undertaking an Open University module ‘Understanding Cardiovascular Diseases’. As well as this I try to play an active role in my local hospital as I am a member of the NHS youth council.

I hope my blogs will be interesting, engaging and intriguing to everyone and I will appreciate any feedback/suggestions.

Guestblogging on medical blog

We are currently looking for guest bloggers on our medical blog.

Are you a doctor, medical student, prospective medical student, nurse, healthcare worker or an expert in a particular medical or health field or do you have personal experience of a medical condition. Are you applying for university in 2013 to study medicine or a medical related subject ?

If so please do get in touch-we would love to hear from you. You can write about anything health & medicine related that you think our readers may be interested in & post links to other relevant medical or health websites if you wish. You can even write about the ups and downs of applying for medicine & share your experiences. You can do this anonymously if you prefer.

If you would like to be a guest medical blogger please do get in touch by e-mail to kate@valuemed.co.uk or by posting in comments and we will contact you. Any e-mail address that you post in comments is kept private and will not appear on the blog.

Would you like to be a guest contributor on our medical blog ?

We are currently looking for guest contributors to this medical blog. Are you a medical student, an expert in a particular medical field or do you have personal experience of a medical condition. If so please do get in touch-we would love to hear from you.

You can write about anything related to medicine, and post links to other relevant medical websites.

If you would like to be a guest blogger please do get in touch by e-mail to kate@adtuk.co.uk or by posting in comments and we will contact you.

Guest bloggers

We have a guest blogger coming online to blog about Acne from his personal perspective

If you would like to join our team of contributors please do get in touch. You can blog about anything health or medicine related.

If you would like to be a guest blogger or contributor please e-mail us or post in comments and we will e-mail you.

Any e-mail address or personal info you leave in comments is kept private

We also have a fertility blog and a drugs and alcohol blog