Wednesday 13 April 2011

I interrupt this blog for an Anti-anti-vaccination rant. Normal programming will resume later.

The other day I managed to get in to a conversation with a few very lovely people on twitter while wading through several lectures on the subject of vaccines. One oddly enough on the controversy around them. I sat in our hour long lecture wondering what bloody controversy? I couldn't help but ask if I was the only person in my hundred and fifty strong clinical immunology class thinking why the hell we were taking the time to pander to the lunatics that claim vaccines are nothing but detrimental to your health! Its a blatant and utter lie. That simple. Nothing more than dangerous, malicious, down right dirty and scare scaremongering lies however, lets take a few moments to have a little indulgent look at it shall we?

I remember when the MMR vaccine controversy broke. Then Mr Andrew Wakefeild claimed to have found a causative relationship between Autism and the MMR vaccine. I remember it so clearly because I have myself Autistic relatives. My cousins are both severely autistic and I remember with so much detail my aunt sat in the kitchen with my mother clearly distressed. She felt as if it was her fault because all of her children had been immunised. Inevitably Mr Wakefeilds study was blasted as one of the worst done pieces of research by a scientist on the planet – I myself would use stronger words than that. Turns out just before the paper had been published in the well respected journal The Lancet he had filed a patent for single Measles vaccine. Not only that he had grossly violated ethics taking advantage of children with disabilities, failing to declare conflicts of interests and falsifying work. Arguably the whole affair might just be the most elaborate fraud in modern day science. You will of course be happy to know Mr Wakefeild was struck off the Medical Register in May 2010 and can now no longer practice medicine in the UK but is still causing trouble over the waters in America.

The effects were much more wide than just outrage in the scientific community, immunisation rates with MMR dropped form 93% to 73% and even as low as 50% in some parts of London. Even though it has been proven that MMR does not cause autism the idea is still there and an idea is even harder to eradicate than the disease itself. In 2008 measles was declared endemic in the UK as a direct result of a decade of low vaccination rates due to the scare. Paul Offit, a doctor at Children's Hospital of Philadelphia said, "that paper killed children.'' The worst part is I wholeheartedly agree.

It seems since then the vast piles of misinformation, lies, and dangerous claims by the anti-vaccination tin hatters seem to have propagated like wildfire. Oddly most of the reasons follow a similar pattern to the above, however not nearly as extreme or quite frankly in my personal opinion cruel but they haven't helped. The notion that giving children too many vaccines can overload the immune system and cause side effects has arisen even though all scientific evidence says otherwise. After all you deal with thousands and thousands of viruses every day, a vaccines is a splash in the ocean compared to what you breath in. Secondly vaccines do not over whelm the immune system. Thirdly even though we now vaccinate against more diseases than we did twenty years ago increased knowledge of the immune system as allowed us to create immune responses with lower vaccine dosages. Fourth all evidence shows that vaccines do not weaken the immune system and lastly and most importantly there is absolutely no evidence what so ever to show the immune system as a role in autism.

However the last point seems to have been completely ignored by the tin hatters. In 1999 the thiomersal controversy broke, groups claimed that the mercury based preservative used in some vaccines caused autism. The US government then ordered it to be removed from vaccines asap, on top of the much more prolific MMR controversy. Not only did it effect vaccination rates but also resulted in some parents attempting to treat their autistic children with “new therapies” off the back of the study that could have potentially been dangerous. Independent research, review of data and population studies rejected the correlation and showed there was no link between thiomersal used in vaccines and autism.

Am I the only one getting a sense of deja vu here?

Many vaccines also use adjuvants aka a vaccines best friend, which are chemicals that help prompt an immune response and enhance the protection that a vaccine can provide you with. Of course these were jumped on by said tin hatters as causing health problems that could screw you up in a number of ways that are longer than my arm. One adjuvant Aluminium was targeted, the truth is all the Aluminium that a child would be dosed with during all the vaccines they would receive though out their life is less than a bottle of formula and there is absolutely no evidence what so ever that Aluminium vaccines cause any problem what so ever.

The safety of vaccines have also become one of their prime target, yes they do cause side effects. Guess what having a needle shoved in your arm hurts of all of three seconds. You might have a little ache for a few hours. You might even feel a bit tired that night. Guess what, its better than getting the disease. There are some people who can not be immunised because of safety concerns, those who are allergic to an ingredient used in the vaccine, people who are immunodeficient and have certain disorders that centre around the immune system can not be vaccinated. For everyone else guess what. You're fine.

The fact that certain groups of the population can not be vaccinated makes keeping rates up even more important. Those who can not be vaccinated are protected by herd immunity which operates on the basis that the more people in the population who are resistant to an infection decreases the chances of someone who is susceptible to the infection coming in contact and therefore contracting said infection. Simple right. The threshold for this “herd immunity” varies between different infections however it generally is around 85% and upwards. Which leads us back to the massive problem that is the drop in vaccination rates thanks to the misinformation and wrong facts circulated by those in the anti vaccination camp.

Sadly the fact of the matter is not getting your child vaccinated or yourself with out a good medical reason that isn't based on hear say and lies isn't just dangerous to yourself but everyone else around you. It puts other people who rely on the herd immunity of a population to protect them. While many of these campaigns also bring up the topic of freedom of choice the truth is you are not a health professional! You do not have all the facts at your fingertips and I find it absolutely disgusting that these campaigns have lead to the resurgence of preventable disease that can be fatal and highly debilitating. The fact of the matter is by choosing to opt out under the disguise of freedom of choice you have put yourself and others in danger.

While I disagree on principal with everything these campaigns say, do and stand for I'm going to sit here behind my laptop screen and say I tried. I tried my damned best to find a shred of evidence to support the anti-vaccination campaigns and found nothing. All I found was that people have died from preventable diseases for no reason and a generation of mothers with autistic children have been left hurt and distressed as a direct result of their false science. So I'm going to put this as bluntly as I can; anti-vaccination propaganda is bullshit. There, I won't sugar coat it and I'm sure as hell not going to pander to it. Take your false science, dangerous and life threatening claims somewhere else and stop undoing the work of generations of scientists trying to prevent disease.

I will tell you this right now. When I have children, they will be vaccinated. End of story.

Sunday 3 April 2011

ENZYME? Whatcha doing today?

DNA also spells DAN!

While you people are waiting for my next post enjoy this while I attempt to study PCR energy kinetics. Kill me now.

Friday 18 March 2011

Maybe you're not runner up - but the first to win the race.

I've spent the last few days wondering what I would write about in here, deciding to just “write” is harder than I thought it would be. However I was chatting away with a friend of mine on MSN this evening while I was studying for a medical microbiology exam on Monday when she said to me; “but Darwin was years ago! Don't you know everything about evolution already?” Sure we've learned a lot but how much is left to learn?

Just because its been over a hundred and fifty years since Darwin published his iconic theory of Natural Selection doesn't mean the controversy has stopped. His theories shock the world and have become the underlying principal of all studies of life, uniting the fields of biology from genetics all the way to ecology and everything in between. Essentially the theory boils down to the fact that we are all modified descendants of our ancestors and that therefore all species on the planet are related through a complex tree of life. A beautifully simple and yet elegant idea that provides the ultimate explanation for the mind blowing diverse beauty that is life on our little blue marble.

This diversification of life is driven by a process called natural selection which works on the basis that there are only so many resources on our planet and all living organisms are fighting each other for them. Those which can claim these resources survive and those which can't do not. Every so often a random change in an organism happens by mutation of their DNA, therefore changing a gene slightly. If this change makes them better at claiming one of these resources then they are more likely to survive, therefore more likely live to pass it on to their offspring. Who would in turn pass it on again and so forth. Eventually this change becomes the norm.

Of course these types of changes happen very slowly, we're talking hundreds of thousands of years or at least for most types of organisms. There is one group where we can watch evolution occurring in a test tube and of course these would be our good friends bacteria! Compared to many organisms on the planet bacteria reproduce stunningly fast anywhere between minutes and hours. Escherichia coli for example is a common bacteria and is present in everyone and without it you would have one very sick tummy! Under optimal conditions the “doubling time” which believe it or not is the time taken for the population to double is 20 minutes. Pretty fast yeah?

There are hundreds of different strains of bacteria just like there are different strains - or breeds as they are more commonly called - of cats and dogs. A recent study using this bacteria has shown that just because you are one of the first to have a mutation that makes you better at something and doesn't mean you will win the evolutionary race. The experiment took two strains of E.Coli and put them together in a petri dish and let them get on with it. As in the real world in this dish the bacteria would have all been competing for resources which take the form namely of glucose, a sugar from which they derive their energy.

The group of highly respected evolutionary researchers headed by Mr Richard Lenski and Jeffrey Barrick grew E.Coli in a lab for 50,000 generations! Around the 31,500 generation mark they discovered that some of the bacteria had developed the ability to derive energy from citrate as well as glucose. The team came up with an elegant and sophisticated set of experiments to see which were better at surviving. They took four different pairs of E.Coli strains and decided to see who would win the battle for resources.

Certain strains grew better than others and became the dominant strains present, this was due to a mutation in a gene called topA which is a transcription factor meaning it controls how other genes are expressed. They also developed mutations in a related gene called rbs which increased the amount of DNA and RNA being synthesised. Of course one would think that these guys would win right? Quickly they developed two mutations that dramatically increased their ability to live...and yet that wasn't what happened.

While these guys had the “big gun” mutations the other strains happily growing along side them gained mutations as well. While these weren't as dramatic but were also important. Eventually it was the quiet underdogs that won out. Believe it or not the strains which had developed the topA and rbs mutations literally had a little rest! While we're not sure why it appears that these genes decided it was time for a nap and while they were resting the slow and steady crowd took over and out numbered their rivals. The long list of experiments done by the team showed that this ability to survive better isn't just down to one mutation, but all of the small added up together.

But truth be told, we don't really know that much about how evolution works on this kind of scale, its a dynamic fluid process and predicting it is a difficult things to do. What this kind of study shows is that the whole genome has to be taken in to account when looking at evolution and not just the one or two genes that are responsible for a certain feature changing. The change over time replies on the fact that one mutation is followed by others and its these later mutations which could play a critical role in making these changes successful!

Of course this makes sense when you have a little thing about it! Take a look at a photo of yourself next to your relatives and you will notice certain features run in your family. You might be tall like your dad, or have your mothers hair, or your grandfathers nose. These characteristics are passed down...but the ability to track them down to one gene has eluded scientists. Height is thought to be determined by at least seventeen genes and chances are many more. Like the example here it could have been one mutation then the many that followed that gave us the variability in human hight.

In the hundred and fifty odd years since Darwin first proposed evolution as an explanation for the diversity of life, we have learned a hell of a lot but we are still attempting to understand the basic molecular mechanisms by which it happens. We have an unthinkable amount still to learn about the nitty gritty way that evolution works, but you know what I think- that it is the wonderful thing about it all!

Robert J. Woods, Jeffrey E. Barrick, Tim F. Cooper, Utpala Shrestha, Mark R. Kauth and Richard E. Lenski. 2011. Second-Order Selection for Evolvability in a Large Escherichia coli Population. Science. 18th March 2011. 331: (6203) 1433 - 1436.

Tuesday 15 March 2011

Under construction.

So here we are. The brain child of a chesty cough and the sudden choice to maybe you know, do something constructive. I must admit however the soul muse in the design of this blog is this utterly amazing, completely brilliant and freaking hilarious Lady Gaga Spoof by Zheng Lab at BCM. I am seriously in love with this song to the point where every time the words “Western Blot” are uttered in university I instantly get it stuck in my head. Anyone who has ever worked or studied in a lab will no doubt relate to everything, plus I want that biohazard dress. I'm so wearing it to graduation.