Lawrence Solomon: April 16, 2014
Several decades following the vaccine’s introduction, the measles death rate rose, largely because the vaccine made adults, expectant mothers and infants more vulnerable
Early in the last century, measles killed millions of people a year. Then, bit by bit in countries of the developed world, the death rate dropped, by the 1960s by 98% or more. In the U.K., it dropped by an astounding 99.96%. And then, the measles vaccine entered the market.
After the vaccine’s introduction, the measles death rate continued to drop into the 1970s. Many scientists credit the continued decline entirely to the vaccine. Other scientists believe the vaccine played a minor role, if that, noting that most infectious diseases similarly petered out during the 20th century, including some, like scarlet fever, for which vaccines were never developed.
The credit for the century-long decline, scientists generally agree, goes to improved nutrition and improved health care, side effects of the West’s growing affluence. In the U.S., the death rate dropped by about 98%, from about 10 per 100,000 population a century ago to one fifth of one person by 1963, the year measles vaccines made their American debut. Both before and after vaccination started, victims tended to be poor.
In the pre-vaccine era, when the natural measles virus infected the entire population, measles — “typically a benign childhood illness,” as Clinical Pediatrics described it — was welcomed for providing lifetime immunity, thus avoiding dangerous adult infections. In today’s vaccine era, adults have accounted for one quarter to one half of measles cases; most of them involve pneumonia, one-quarter of them hospitalization.
Also importantly, measles during pregnancies have risen dangerously because expectant mothers no longer have lifetime immunity. Today’s vaccinated expectant mothers are at risk because the measles vaccine wanes with time and because it often fails to protect against measles.
Continue reading here: