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What’s all this about vitamin A and measles?

            The measles outbreak that began a few weeks ago is one of the largest in recent years, and so far it has claimed the lives of two persons, one a child. Neither victim had received the measles vaccine. Media stories about vitamin A are confusing, if not misleading, so let’s clarify things.

            Vitamin A is essential to maintain the integrity of the skin, eyes and immune system. Many common foods contain vitamin A or its precursor, beta-carotene. The former can be toxic when taken chronically in high doses but the latter almost never is.

            Before we had a measles vaccine in the mid-1960s, few children escaped this illness. About one child in a thousand died from the disease and about one in five hundred suffered from devastating inflammation of the brain. Approximately half of the children who were apparently spared such serious complications were found to have a low-grade inflammation of the brain that impaired their school performance for months, perhaps longer. Many also suffered from weakening of their immune system that left them open to other common infections, such as pneumonia. Thus, it was not as benign as we thought.

            There is another frightening complication of measles that most people are unaware of: subacute sclerosing panencephalitis, known as SSPE. It is now almost non-existent in this country as a result of widespread vaccination. SSPE may occur several years after a bout of measles and the incidence ranges from about one in 600 to one in 5,000 victims. Expect to see this devastating, always fatal inflammation of the brain in years to come if parents’ current refusal to immunize children continues,

            While vitamin A deficiency is quite uncommon in the United States the opposite is true in the developing world, and it is severe in some countries. It is not only a major, if not the leading cause of blindness in children in Africa, but it plays a leading role in measles mortality. In some developing countries the seriousness of measles is magnified by orders of magnitude. Whereas during my early practice years we lost one child out of a thousand, among vitamin A-deficient children in some parts of Africa the mortality rate is as high as 400 out of a thousand – a staggering forty percent! That number falls dramatically when children receive adequate amounts of vitamin A in their diet over the long term, before they are exposed to the measles virus.

            N.B.: There is more to the story. Vitamin A-deficient children are also lacking in other vitamins and minerals, and they are almost always severely deficient in protein, which is supremely important in maintaining the immune system.

            VITAMIN A DOES NOT PREVENT OR CURE MEASLES. However, the standard of care, even in the United States, is to give a child hospitalized with measles, usually because of the common complication of pneumonia, two doses of 200,000 units of vitamin A. Although chronic overdosing with vitamin A can cause severe problems, there is no risk in administering that amount in a hospital setting. An important caveat: a child who has or has been recently exposed to measles should not be given extra doses of the vitamin. There is no evidence that this will mitigate the seriousness of the disease or lead to a shorter course of the illness.

            There is no cure for measles but the usual two doses of the vaccine have an effective rate of 97 percent. Serious side effects of the vaccine are almost non-existent; the occasional high fever or rash may in fact indicate a vulnerability to the virus that in its wild form could cause death or brain damage.