Pertussis vaccine and new mutations in the pathogen that existing vaccines are unable to effectively control. Some studies have suggested that while acellular pertussis vaccines are effective at preventing the disease, they have a limited impact on infection and transmission, meaning that vaccinated people could spread the disease even though they may have only mild symptoms or none at all. For children, immunizations are commonly given in combination with immunizations against tetanus, diphtheria, polio, and haemophilus influenzae type B at two, four, six, and 15–18 months of age. A single later booster is given at four to six years of age (US
Vogt–Koyanagi–Harada disease Vogt–Koyanagi–Harada disease Vogt–Koyanagi–Harada disease (VKH), also known as Vogt–Koyanagi–Harada syndrome, uveomeningitis syndrome and uveomeningoencephalitic syndrome, is a multisystem disease of presumed autoimmune cause, that affects pigmented tissues, which have melanin. The most significant manifestation is bilateral, diffuse uveitis, which affects the eye. VKH may variably also involve the inner ear with effects on hearing, the skin, and the meninges of the central nervous system. The disease is characterised by bilateral diffuse uveitis, with pain, redness and blurring of vision. The eye symptoms may be accompanied by a varying constellation of systemic symptoms, such as auditory (tinnitus, vertigo, and hypoacusis), neurological