San Antonio Express-News (Sunday)
Mass vaccinations used against diphtheria in 1970
Wasn't there a time in the late 1960s where we had a diphtheria epidemic? I remember as a teen standing in line at what was then Municipal Auditorium to be inoculated.
— Liz Marshall To many readers, diphtheria might sound like an antique disease, associated with the story of Balto, the husky hero of the eponymous 1995 animated movie about the leader of a sled-dog team that brought antitoxin serum from Anchorage to suffering children during a 1925 epidemic in Nome.
But well within living memory, the bacterial illness infected an alarming number of San Antonians, made national news and led to a state law mandating a vaccine for schoolchildren.
Transmission of this highly communicable upper-respiratory disease is airborne, spread by coughs and sneezes. The diphtheria bacterium takes hold and multiplies in the nose and throat, where it produces a toxin that kills healthy tissue.
While some infected people are asymptomatic, common symptoms include a sore throat, low-grade fever, nausea and headache. As the disease progresses, it can lead to respiratory failure. If the toxin reaches the bloodstream, it can cause nerve and organ damage.
The disease is treated with antitoxin and antibiotics. But even with treatment, according to the CDC, fatalities can be as high as one in 10 and one in five among children younger than 5. Without treatment, diphtheria kills as many as one in two sufferers.
Children younger than 15 are most susceptible, although adults also may be infected.
At the time of the San Antonio epidemic, a vaccine derived from diphtheria toxoid had been in common use for nearly 50 years, and only a few hundred cases were reported annually nationwide. The vaccine rate nationwide then was 70 to 80 percent.
As summarized in the Annals of Internal Medicine, Oct. 1, 1971, known cases of diphtheria in San Antonio reached 201 between Dec. 1, 1969, and Dec. 31, 1971. There were three fatalities, all unimmunized children.
The highest rate of diphtheria cases since the early 1960s was reported in 1969, starting in the early fall. There were nine cases, as compared with three the previous year and none in 1966 and 1967, according to San Antonio Metropolitan Health figures quoted in the San Antonio Light, Dec. 25, 1969. Into the new year, the number of cases continued to climb, with another 22 by March 1970.
The diphtheria vaccine, administered in three shots, wasn’t getting to all the city’s children. The Bexar County Hospital District began giving it to all children 14 and younger who were admitted to the hospital for any reason, and Metro Health began an aggressive Spanish-language campaign to get families to clinics offering free vaccines.
The county considered a mass inoculation campaign but scrapped the idea because the need to give a series of three shots made it “impractical,” the Light reported March 11, 1970.
Instead, the San Antonio School District — where a majority of the cases had developed — and the city’s Catholic schools planned a fall 1970 immunization project and resolved not to enroll children who hadn’t received the vaccine.
It was all too little, too late. Through the spring, more outbreaks occurred in the Edgewood district and at Leon Valley Elementary School in the Northside District. The disease first was represented as “near epidemic” in San Antonio in May 1970, with hopes that the end of the school year would curtail its spread. It didn’t.
Through the summer, cases rose, with eight in July alone — unexpected, because the disease usually peaks in the winter — and Metro Health held a series of clinics in community centers and public-housing projects over two weeks in July to immunize children between ages three months to 10 years, with flyers and sound trucks advertising the events. Attendance was described as “very disappointing” by public-health officials.
The infection’s grip on the city was first called an “epidemic” after the death of a 6-year-old boy from “the suffocating disease” on Aug. 4, 1970, as reported in the next day’s issue of the San Antonio Express.
Roger Garcia had been treated for nearly a week at Bexar County Hospital before he became the third diphtheria fatality here for the year.
The deaths and the year’s total of 17 new cases by midAugust spurred a city-county plan for mass immunization clinics at existing public-health clinics and new, temporary locations. This time, the plan was carried through.
The largest and best-known of the mass vaccine sites was the Municipal Auditorium, where thousands of adults and children lined up Aug. 19-21, 1970, for shots. This megaclinic was staffed by public-health employees and volunteer nurses and doctors, Navy corpsmen and medics from Fort Sam Houston.
Meanwhile, the case numbers topped 50, providing “an almost unbelievable motivation” to get the jabs, as reported in the Express, Aug. 22, 1970. Patients left with a card reminding them to return for the next in their series of three.
The infection toll continued to climb, and for the first time, events and gatherings were canceled in late August, since diphtheria is spread by close contact. Some school districts applied “diphtheria exclusion” rules, requiring students to have proof of immunization.
Like the influenza epidemic of 1918, sometimes said to have lasted until 1923, San Antonio’s diphtheria epidemic didn’t go away with the end of 1970. There were another 47 cases in 1971, but no fatalities, and mass immunization drives continued at neighborhood clinic.
In spring 1971, the Texas Legislature enacted a law that made immunizations against smallpox, diphtheria, tetanus, polio, rubeola and rubella mandatory for the state’s schoolchildren.
Over the next few years, the law appears to have led to “a substantial decline in morbidity of the vaccine-preventable diseases,” as demonstrated in Public Health Reports, JanuaryFebruary 1973.
It’s not known why diphtheria flourished in San Antonio in 1970. There were higher-thannormal cases in Chicago and Miami as well that year, but San Antonio was hit the hardest. One explanation was a comparatively low-income population with poor access to health care, especially among people of color.
“The rate for Blacks and Chicanos was 12.5 times as high as that for Anglos,” stated a paper on the epidemic published in the Journal of the American Medical Association, April 16, 1973. “The incidence rate for the upper 25 percent of the population by socioeconomic status was 5.6 cases per 100,000; for the lower 25 percent, it was 62 cases per 100,000.”
If you survived the 1970 epidemic or remember lining up for immunizations, contact this column to share your memories. Responses may be featured in a future column.