By Paul Sisson
The San Diego Union-Tribune
SAN DIEGO — Hundreds of San Diego State University undergraduates who received vaccinations against type B meningococcal disease at Viejas Arena on Oct. 5 and Oct. 8 must receive replacement inoculations after Walgreens Inc. determined that the doses it delivered were improperly handled.
In a brief statement, the company said that it “became aware that the vaccine temperature at the time of administration was not optimal” for 350 students who the pharmacy chain’s workers immunized during the two mass vaccination clinics, which were prompted by a three-case outbreak that the county declared in September.
The company said it believes that re-vaccination is necessary to ensure the “full efficacy of the vaccine,” but assured the affected students and their families that receiving an off-temperature vaccine posed “no associated safety risk.”
Dr. Wilma Wooten, San Diego County’s public health officer, said Friday morning that Walgreens’ assertions are accurate. Studies, she said, have not found safety problems when vaccines are not kept withing the proper temperature ranges.
“Loss of effectiveness is the primary issue that can occur when the proper temperature isn’t maintained,” Wooten said.
A 2018 research paper from the U.S. Centers for Disease Control and Prevention examined five years of data from the national Vaccine Adverse Event Reporting System and discovered 476 reports of vaccines that were used after being kept outside their recommended temperature ranges.
Researchers found that 32 of those reports involved patients who experienced adverse vaccine reactions. Minor “local reactions” such as swelling and soreness or redness at injection sites were the most common consequences of receiving an off-temperature vaccine.
Many different vaccines, and all of those that target meningococcal disease, require refrigeration to maintain their potency.
Package inserts approved by the U.S. Food and Drug Administration state that Bexsero and Trumenba, the only two type B vaccines on the market, must be refrigerated at all times and kept between 36 degrees and 46 degrees Fahrenheit.
Typically, on-site vaccination events, like those that occurred at Viejas Arena, use special coolers equipped with “logging” digital thermometers to keep running tallies of vaccine temperatures during transport. These special temperature gauges must have formal accuracy certifications, allowing public health investigators to verify that vaccinations were always held at the proper temperature.
It’s a chain of custody that presented an extra layer of complexity during the county health department’s recent hepatitis A vaccination campaign which sent small foot teams of public health nurses, paramedics and other health care workers into homeless camps, canyons and other out-of-the-way locations to give more than 100,000 doses. At all times, everyone doing this work had to be trained in properly using the temperature logging equipment to keep the vaccine supply within the specified temperature range even when working outside during the hottest months of the year.
Wooten said all county employees who handle vaccines, herself included, are required to take annual training in proper handling procedures.
It was not clear Friday morning whether Walgreens employees received similar training or how long the vaccines in question were held outside the proper temperature range. A company spokesman said such additional information was unavailable.
Wooten said the county health department does not investigate such incidents, which are within the purview of the California State Board of Pharmacy.
In addition to Walgreens, nurses with Kaiser Permanente and county public health nurses were present at the two early-October vaccination events at Viejas Arena. Wooten said that about 3,000 doses were administered across all three organizations during the event, and all doses given by Kaiser or county nurses met temperature requirements.
Copyright 2018 The San Diego Union-Tribune