Meningitis is an infection of the membrane which covers the brain and the spinal cord, and can be caused by infection with bacteria and viruses. There are several types of meningitis of which Hib meningitis is one, and I will discuss each of them in successive articles, published at approximately two weekly intervals.Hib meningitis the form of meningitis caused by the haemophilus influenzae type B bacterium. This form of meningitis is particularly dangerous to children, and was the form which caused most deaths to under fives from meningitis, particularly those between the ages of 3 to 36 months. Due to the Hib vaccine it is now very rare in developed countries, though has not yet been eradicated. The vaccine is very effective and Hib meningitis is no longer a significant risk in those countries that have included the vaccination as part of its childhood vaccination program.

Hib Has No RashUnlike other forms of meningitis, the Hib bacterium does not cause a rash, but it does display the other symptoms associated with meningitis such as high temperature, sore throat and headache, sensitivity to light and several other symptoms, some of which are evident only to the mother. These, and other symptoms, are discussed in more detail on my website and blog. Due to modern medicine, 95% of cases with Hib meningitis recover, though up to 12% of these are left with long term problems such as deafness, brain damage and epilepsy.The bacteria live for a short while in the throat and the back of the nose, and are transmitted by contact with aerosol emissions from the throat, such as coughing or sneezing, and other contact with throat fluids. They cannot live outside the body and are not associated with animals other than humans. Hib carriers do not necessarily become ill; in fact the majority do not, so it is not sufficient to stay away from known infections as with most other childhood diseases. It was quite common for the bacteria to be carried by healthy children, though this is now rare due to the almost universal adoption of the Hib vaccine in the developed world.

The Hib Vaccine Was Difficult To DevelopSo, how about the vaccine? The Hib vaccine is what is known as a conjugate vaccine, which means that it is made by combining a small part of the bacteria with a protein. Initial attempts to produce a vaccine were foiled by the physiology of the bacterium. The part which was required to stimulate the human immune system to produce antibodies is a sugar on the surface which is not easily taken up in the body, and after much experimentation with mice a way was found to couple this sugar with a protein which enabled it to be easily absorbed by the human body.The vaccine is very effective and very safe, and since its initial testing in the mid 1990s and introduction into national vaccination programs, the incidence of Hib meningitis has decreased dramatically by around 90% saving the lives of countless young children. It is now part of the vaccination schedule of most developed countries, though there is a significant difference between those of the USA and the UK which is worthy of investigation.