Malaria RTS,S Vaccine

I recently did some private study on malaria and the development of the RTS,S vaccine which is "the first malaria vaccine candidate to ever reach large-scale Phase III clinical testing"  (http://tinyurl.com/cm6q6zx). You can find about the outline of clinical trials on the 'Clinical Trials' page.

What I found was that although there are currently ways of preventing malaria or treatments that are available once malaria is contracted, a lot of them take time to teach people how to use them and other solutions have to be replaced after a certain time period. For example; I looked at LLIN's and ITN's and the comparison between them. I found that LLIN's (long-lasting insecticide-treated mosquito nets) were of a better standard than ITN's (insecticide-treated mosquito nets) because they last around 3 years opposed to 12-18 months. This means that the distributor (mainly the WHO) does not have to go back to the same place every year but can distribute further afield or spend time funding other projects.

Another solution are antimalarial drugs, but mosquitoes are becoming/have become resistant to certain drugs; as was reported today; "scientists have found new evidence that resistance to the front-line treatments for malaria is increasing" (http://www.bbc.co.uk/news/health-17628172).

IRS (indoor residual spray) is another option but there are issues to do with the component of the spray; DDT (Dichlorodiphenyltrichloroethane) which is thought by many to have environmental impacts and also health impacts, although the WHO disagrees and; "announced that this intervention will once again play a major role in its efforts to fight the disease; Dr Anarfi Asamoa-Baah, WHO Assistant Director-General for HIV/AIDS, TB and Malaria said; DDT presents no health risk when used properly” (http://www.who.int/mediacentre/news/releases/2006/pr50/en/).

Therefore, the newest development in the fight against malaria to prevent the disease that affects millions of people every year is the RTS,S vaccine. It has been under development for 25 years and is the most clinically advanced malaria vaccine there has ever been and there has been a huge amount of investment in the development by a number of huge companies.

Results from the Phase III trials were released in 2009 by the "New England Journal of Medicine". On their website there are a number of interesting tables and graphs to show the effectiveness/efficacy of the vaccine and the methods of trialling it, who they administered it too and the effects that the vaccine had. One table that I found very interesting was to do with 'serious adverse effects' (7th table on the right hand side (http://www.nejm.org/doi/full/10.1056/NEJMoa1102287#t=articleResults)). The results look shocking when you see how many more adverse effects there were in the malaria group than the control drug, but then I noticed that the group that it was administered was double that of the control in both the '6-12 week' and '5-17 month' test groups. This seems to point towards the age groups that this drug will be administered in and leads to the question of safety for the children that it is being tested in; but as the tables data shows (and the other data), it appears to be a very safe vaccine.  

In terms of issues of cost, organisation, transportation to the areas where the vaccine is needed i.e. sub-Saharan Africa and administering the vaccine to the patients; I think that these will all be overcome by the co-operation between GlaxoSmithKline Biologists and organisations such as the WHO but also through the governments of the countries that need the vaccine for their people. The amount of people that will be saved by this vaccine in the future is worth more than the effort that is needed for organisation of producing and distribution of the vaccine itself. 

I would say that the RTS,S vaccine is a very good solution to the issue of malaria control. I think that it would be very effective if used in combination with other alternative malaria controls such as LLIN’s (which I feel would be a lot more successful than ITN’s) and also IRS. I think that GlaxoSmithKline Biologicals and other biological companies should continue their work and strive to develop a second generation malaria vaccine that performs even better than the first generation RTS,S vaccine.

Exotic Diseases

I found in the WEEK that it was reported in the Sunday Times last Sunday "exotic diseases are heading our way" (The WEEK 10th March 2012 page 14). I can't find the article on the internet so I will give you the gist of what it was saying; "climatologists' predict and influx of exotic diseases from warmer climes, with cattle farms experiencing infections of Schmallenberg virus, which causes stillbirths and deformities in young livestock. How long before illnesses that have reached Spain and Portugal get to us? Or human diseases such as malaria and encephalitis?" (The WEEK 10th March 2012 page 14).

So what are the issues we face here? Firstly, in terms of malaria risk, by having the Anopheles mosquitoes coming to Britain the risk of getting malaria does increase (not all mosquitoes cause malaria-only the female Anopheles). Malaria is caused by a parasite known as Plasmodium (four main types; P. vivax, P. ovale, P. malariae and P. falciparum) getting into the Anopheles mosquito through a blood meal that it takes from a person already with malaria. The mosquito then acts as a vector for the Plasmodium, which breaks into its salivary gland. When the mosquito takes another blood meal, the Plasmodium is passed directly into the human's (second host's) blood in the saliva from the mosquito. The parasite then invades the liver cells where they multiply, then escape out into the blood and the red blood cells where they continue to multiply and break out into more and more red blood cells. The cycle then continues. There are a number of ways of trying to prevent the transmission of malaria such as bed nets and sprays, but what biologists are hoping will be the best solution is the RTS,S vaccine that has been in development for the last 25 years.

Secondly, the other disease mentioned in the article was encephalitis; "inflammation of the brain usually caused by a viral infection" (http://www.patient.co.uk/health/Encephalitis.htm). There are a number of different viral infections that can cause encephalitis including "herpes simplex virus (the virus that causes cold sores and genital herpes), varicella zoster virus (the chickenpox virus), mumps virus, measles virus and flu viruses" (http://www.patient.co.uk/health/Encephalitis.htm). But in other areas of the world there are other ways of getting encephalitis such as through mosquitoes which is where this article is coming from in terms of increased risk with the change in climate. In the UK the most common cause through viral infection  "is herpes simplex virus" (http://www.patient.co.uk/health/Encephalitis.htm). But not to worry because at the moment encephalitis is very uncommon, but just if you do get it get to hospital very quickly because "in many people, encephalitis is a serious condition and can be life-threatening" (http://www.patient.co.uk/health/Encephalitis.htm).

Personally I think that the risks are low and that for the time being we should not be worried about these exotic diseases coming to our country because we have the capability of dealing with them if we need to and the healthcare is good enough to aid us. The issue that needs to be addressed is that of malaria in other countries, we are a long way towards that goal with the RTS,S vaccine and the other solutions that we have developed.

Another interesting story; about Coca-Cola and Pepsi, and the effect that their current ingredients have on cancer http://www.bbc.co.uk/news/world-us-canada-17308181, and the warnings that they may have to put on their cans if they don't change their ingredients.