Whenever we endure another flu season, many of us wonder how good (or useless) the vaccine was. The first reaction is to question the strains that were covered. However, another unforeseen problem may be that the vaccine was just not effective because of incorrect care in transport or storage.
Patrice La Vigne authored an article, Bad Batches: The Effect of Temperature Fluctuations in Vaccines, published by the National Vaccine Information Center, exploring just that. What if vaccine effectiveness was altered by changes in temperature?
Most people don’t know that the quality and effectiveness of vaccines is dependent on proper transport, handling and storage by both manufacturers and providers. Ineffective vaccines are probably more prevalent than people realize, causing a lot of waste and revaccination.
Does Temperature Play a Role?
The World Health Organization (WHO) reports that, unlike chemical drugs, vaccines are affected by changes in conditions during transport and storage, reducing the products’ safety, efficacy, and shelf life. To ensure adequate transport and storage temperatures for vaccines, the Centers for Disease Control and Prevention (CDC) provided general cold chain recommendations with a limited temperature of 5°C and range of 2° to 8°C. Each manufacturer must also provide storage procedure instructions for their vaccines. There are a number of factors that affect loss of potency. Some vaccines can be heat sensitive while others are freeze-sensitive (without any indication that freezing occurred).
Studies detail faulty storage
There are few data studies that track vaccine storage and handling practices, but among the reports conducted, problems were found.
A study observing private physician offices in Georgia—even after a 1997 CDC draft manual was developed—found less than optimal vaccine storage and handling practices. The study divided 263 medical offices into two groups. About half received the draft manual (intervention group), while the other half didn’t. After two months, graduate students visited the sites to measure refrigerator and freezer temperatures—and conducted interviews about handling of vaccine deliveries, vaccine storage and management of problems.
Surprisingly, there were no significant differences in vaccine storage practices between the intervention and control offices. Only 26% of the offices had written instructions for handling vaccines. Seventy-three percent of office employees knew the correct temperature ranges for storage, but several could not read the mercury thermometer. Some incorrectly lowered their refrigerator controls because they thought colder temperatures were safer, increasing the risk for freezing vaccines. Unfortunately, 20% of freezers and 7% of refrigerators were missing thermometers, altogether. While more than 60% of the offices kept up-to-date temperature logs, several of these logs indicated that the vaccines had been kept outside of recommended ranges for weeks.
Over the years, there has been some improvement on cold chain processes, assisted in part from greater government agency efforts. In 2000, the Advisory Committee on Immunization Practices (ACIP) and the American Academy of Family Physicians (AAFP) stressed that adequate storage is important. They reiterated the CDC’s guidance that certain vaccines are sensitive to warmer temperatures, while others are sensitive to freezing temperatures. It’s not easy to distinguish when a vaccine has gone bad from temperature deviations. The ACIP and AAFP stressed that mishandled or expired vaccines shouldn’t be administered.
In 2002, a report comprising 721 primary care physician offices revealed that almost 80% adhered to vaccine storage guidelines, and most of the vaccines had not expired. Researchers did note that quality improvement activities and programs—such as distribution of thermometers and offering feedback about compliance—helped to improve how primary care physicians store vaccines.
Still not perfect
A 2007 review of 35 worldwide studies concluded that between 14% and 35% of vaccines are still subjected to accidental freezing. Interestingly, 16.7% were exposed to freezing temperatures during transport in developed countries, but 35.3% in developing countries!
La Vigne cites a few examples where out-of-range temperatures led to revaccination, including:
- A San Mateo Peninsula Pediatrics office employee noticed freezing temperatures—unchecked for months—in one of the two refrigerators where ten different childhood vaccines were stored. Because of possible ineffective vaccines, 1,551 families were notified and offered repeat vaccinations free of charge.
- In Oregon and Washington, Kaiser Permanente recalled 35,000 doses of the Fluvirin flu shot after it was believed the batch got too cold during shipment. Patients who received vaccinations were advised to be revaccinated.
Implementing a solid cold chain policy, properly storing and handling vaccines from the manufacturer to the physician’s office can solve many of these problems.
Know if your vaccine has a temp
American Thermal’s temperature monitoring solutions can assure that any vaccine cold chain works effectively—and quickly indicates if there has been a temperature breach.
ATI’S electronic temperature monitoring devices provide easy access to time and temperature data throughout your product’s journey. Whether it's an electronic indicator or data logger, you can pull valid temperature history that will allow you to know if your product or consumer could be at risk.
Threshold temperature indicators—ascending, descending, or dual monitoring labels—will tell the physician if the efficacy of the vaccine has been affected. You can choose affordable, accurate, dependable monitoring solutions with response temperatures as low as 0°C. They easily apply to packaging.
We help our pharmaceutical customers develop the perfect temperature monitoring programs and offer continued support to make sure everything is effectively implemented to meet their needs. In short, we give them tools to maintain vaccine effectiveness—the best shot for everyone!