By correcting a potential error, health officials in Ventura County, California, accidentally made another – and jeopardized vaccines administered to thousands of people.

County health officials, concerned that the vaccines were heating up too much when they were being transported to clinics, changed their protocol in 2017. But a routine audit found that the ice packs that were being pumped out of the water were not safe. they used could have frozen some drugs and reduced their effectiveness.

Officials offered to re-immunize anyone who received a vaccine delivered in a defective package.

"There is no way of saying whether or not they were ineffective," said Jason Arimura, director of pharmacy services at the pharmacies of Ventura County Medical Center. As a precaution, he said: "we just warned everyone".

The number of patients affected: 23,000.

This is not the only case of vaccines fears to be ineffective in reaching patients. In the last 13 months alone, 117 children from an Oklahoma City Indian health clinic have received vaccines against polio, meningococcal disease and human papillomavirus that have been inappropriately refrigerated. .

Similar issues related to temperature control prompted an Indianapolis dispensary to send letters last year proposing to offer revaccination to 1,600 people, according to local news reports.

Kentucky officials now say that potentially ineffective and contaminated vaccines have been administered in several companies in Kentucky, Ohio and Indiana.

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The federal government sets standards for vaccine storage. But not all health care providers are required to follow these guidelines.

The federal Vaccines for Children program, which provides these drugs free of charge to children from low-income families, requires clinics, doctors and other providers to use state-of-the-art equipment, including devices to continuously monitor temperature, annual audits . Suppliers must also report issues to federal authorities.

More than 44,000 physicians participate in the program, according to the Centers for Disease Control and Prevention. They provide vaccines to 90% of the country's children.

However, out-of-program medical institutions, including many private pharmacists and internists, have no comparable federal oversight. Vaccine storage protocols and the ability to report cases of patients receiving ineffective drugs are largely left to their discretion.

The vaccines involved in the Ventura County recall were not part of the Vaccines for Children program.

According to analysts, most hospitals, clinics and doctors keep their vaccines vigilantly. Research suggests that the administration of compromised vaccines to patients is not harmful.

L.J Tan, head of strategy for the Immunization Action Coalition, a non-profit immunization advocacy group, said the country's vaccine stock was probably "among the safest in the world."

But Dr. Julie Boom, pediatrician and director of the vaccination project at Texas Children's Hospital, warned that manipulating these drugs inappropriately meant wasting expensive drugs, and that the use of compromised vaccines "could create a pocket of people under-immunized. "

"We do not want that to happen," she said.

In Ventura County, temperature problems have affected vaccines against influenza, tetanus, diphtheria, whooping cough and hepatitis B. Officials have informed patients who had been screened for TB and some who had received penicillin to treat syphilis, that their drugs would also have been compromised.

About 1,200 had returned to be revaccinated until January, says Arimura. Revamping the 23,000 people would cost $ 1.3 million, he says.

Vaccines are extremely sensitive to temperature fluctuations. In some cases, says Tan, exposing a vaccine to an adverse environment can effectively kill live viruses and harm the proteins in the vaccines.

Generally, temperature problems occur during the transport of drugs.

According to Boom, without proper supervision, it is almost impossible to know if the vaccines have been exposed to extreme temperatures.

The Inspector General of the Department of Health and Social Services studied the suppliers of childhood vaccines in 2012.

The Inspector General found that within two weeks, three-quarters of the 45 sampled providers had exposed their vaccines to inappropriate temperatures for at least five cumulative hours.

In another study, researchers at federal disease control and prevention centers found that 23% of vaccine errors reported to the federal surveillance system from 2000 to 2013 involved improper storage or the use of outdated vaccines.

Since these reports, the CDC has put additional requirements in place for the children's program, including daily minimum and maximum temperature recording of the vaccine storage unit.

Dr. Paul Hunter, associate professor of family medicine and community health at the University of Wisconsin, said the federal oversight was "very good."

"On the whole, they do it very regularly," he said.

Outside the federal surveillance system, financial problems may encourage physicians and clinics to take special precautions during vaccination. A dose can cost hundreds of dollars.

Sanford Health, a health care system based in South Dakota and active in the Midwest, strives to make federal requirements the standard for vaccines for its health care providers.

The system has launched Vax Champ, a six-month training program that teaches nurses how to store and handle vaccines properly. The program asks participants to periodically take pictures of their vaccine stocks and send lists of inventory for review.

The vaccine manufacturer, Sanofi Pasteur, funded the program.

Andrea Polkinghorn, head of Immunization Strategy for Sanford Health, said that vaccine storage systems vary widely from one provider to the other. The purchase of pharmaceutical grade storage equipment is expensive, she says, and the vendors are at different stages of the upgrade.

"But if you compare that to the planned vaccine loss," Polkinghorn said, "the end is worth it."

Kaiser Health News (KHN) is a non-profit news service covering health issues. It is an independent editorial program of the Kaiser Family Foundation which is not affiliated with Kaiser Permanente.