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Glitches hamper rollout of Moderna’s vaccine

The Cambridge biotech says the problems are related to distribution issues beyond its control.

A woman holds a vial of the Moderna COVID-19 vaccine in the gymnasium at International High School in Paterson, N.J., Wednesday.Ted Shaffrey/Associated Press

Moderna’s COVID-19 vaccine may be a triumph of biotechnology, but its rollout has hit snags lately, from California to Maine.

They illustrate the challenges facing President Biden, who promised before his inauguration Wednesday that the government will administer 100 million doses of coronavirus vaccine during the first 100 days of his administration.

That won’t be easy, if recent events are any indication. On Sunday, California’s state epidemiologist recommended that the state pause the distribution of more than 330,000 doses of the Cambridge company’s vaccine after a “higher than usual” number of people showed signs of a possible severe allergic reaction.

Two days later, health officials in Maine and Michigan said more than 16,000 doses spoiled because of temperature control problems during delivery and would probably have to be disposed of.


And on Wednesday, New York Mayor Bill de Blasio said the city was rescheduling 23,000 vaccine appointments because of a supply shortage. He said Moderna and Texas-based distributor McKesson Corporation had told city officials that 103,000 doses expected to arrive Tuesday will be delayed for a couple of days, according to Bloomberg News.

McKesson, which has a government contract to deliver the Moderna vaccine, confirmed in a statement Wednesday that “certain deliveries” that went out Sunday arrived colder than minus-13 degrees Fahrenheit, the lower end of the recommended temperature range. The company blamed the problem on gel packs that were found to be too cold.

McKesson is replacing those doses as well as others slated for shipment that were held up because of the same problem. The firm said it has “taken steps to prevent this from occurring in the future.”

Ray Jordan, a Moderna spokesman, said the company couldn’t comment on most of the problems because they were distribution matters that involved the federal program Operation Warp Speed and McKesson. The government has so far ordered 200 million doses of Moderna’s vaccine.


“Our contract has us delivering batches to the US government, and then they do the final delivery, working with McKesson as their primary strategic distributor,” said Jordan. Moderna delivers the doses to a government depot at a location that Jordan said he can’t disclose for security reasons, and then McKesson handles distribution.

As for the pause of vaccinations in California, Moderna said in a statement Tuesday that several people at a vaccination center in San Diego were treated for possible allergic reactions after they received shots from the same lot of the vaccine. Moderna said it was “fully cooperating” with the California Department of Public Health and was “unaware of comparable clusters of adverse events” at other sites that administered vaccines from that lot.

The CDPH said more than 330,000 doses from the lot were distributed to 287 providers across California and that that fewer than 10 people at the San Diego clinic who received the shot needed medical attention over the span of 24 hours. A total of 307,300 doses remain in storage and have not yet been distributed.

Dr. Paul Offit, an infectious diseases expert at Children’s Hospital of Philadelphia who sits on a panel of outside experts that advised the Food and Drug Administration to clear coronavirus vaccines from Moderna and Pfizer-BioNTech for emergency use, described the halt of vaccinations in California as an overreaction.

“There’s no such thing as a bad vaccine lot,” he said. “We haven’t had one since the Cutter incident in 1955.”


He was referring to a notorious episode when 120,000 children were inadvertently injected with the live infectious poliovirus from a vaccine manufactured by Cutter Laboratories in Berkeley, Calif. About 164 recipients were severely paralyzed and 10 died because the manufacturer had departed from Dr. Jonas Salk’s safe production protocols to inactivate the virus.

Offit said it was more likely that medical staff who administered the coronavirus vaccine in San Diego did something wrong or used a different standard to interpret the formula’s not uncommon side effects as a severe allergic reaction.

With California experiencing one of the most acute coronavirus outbreaks in the nation, he added, halting vaccinations statewide due to concerns at one location “wasn’t a cautious thing to do ― it was a radical thing to do.” Thousands of people who can’t receive the vaccine during the pause might get sick or die, Offit said.

As for the other problems, including vaccine doses that spoiled or are being delivered late, he said they were predictable glitches given the vaccine’s cold-storage requirements and the massive scale of the rollout.

On Tuesday, Maine officials announced that they might have to throw out 4,400 doses of the Moderna vaccine delivered the day before to 35 sites across the state. Electronic thermometers outside the boxes flashed a red “X” on the monitors’ screens, indicating that the vials had spoiled due to improper temperatures at some point during the journey.

“It’s always unfortunate when logistical issues of this nature crop up but it’s also good to remember that the system has these safeguards in place so that if they happen, we know about them immediately,” Dr. Nirav Shah, director of the Maine Center for Disease Control and Prevention, said at a news briefing, according to the Washington Post. A similar thing happened with almost 12,000 doses delivered Sunday to Michigan by McKesson.


The vaccines from Moderna and Pfizer-BioNTech were cleared for emergency use by the Food and Drug Administration last month and rely on new technology called messenger RNA. They were a remarkable 95 percent effective at preventing COVID-19 in large late-stage studies.

Both vaccines must be kept at super-cold temperatures during delivery. The Moderna vaccine must be stored between minus-13 and 5 degrees Fahrenheit, according to guidance from the Centers for Disease Control and Prevention. In both the Maine and Michigan episodes, the shipments got too cold.

Officials at Operation Warp Speed, which bankrolled the development and manufacturing of Moderna’s vaccine, declined to respond to requests for comment.

Jonathan Saltzman can be reached at