After visit, California health department says everyone who got vaccinated at Coliseum is OK

The California Department of Health has concluded that everyone who got vaccinated on March 1 at the Oakland Coliseum is OK, despite possibly receiving a less-than-optimal dose of the Pfizer vaccine.

Ali Bay, deputy director of communications for the health department, reached out to KTVU on Friday in an email, saying that no one who got vaccinated on that day in question "has been harmed or would be harmed if we conclude they received a slightly smaller dose of the vaccine."

Bay stressed that no one needs to seek additional medicare care.

However, Bay added: "If any additional action, that would be any different than a scheduled second dose, is needed (such as a booster), we will let patients know immediately."

Bay said that health officials visited the Coliseum following a KTVU report "out an abundance of caution." 

Bay added that the health department is working with the U.S. Health and Human Services, Centers of Disease Control and Prevention as well as the vaccine manufacturer Pfizer, to "ensure that vaccine best practices and quality assurance are adhered to at this site."

The California Department of Health neither confirmed nor denied two EMT accounts provided to KTVU earlier in the week. And it's unclear if health officials talked to the various workers at the site to determine what happened. No one from the health department answered KTVU's follow-up questions.

The two EMTs, who asked to remain anonymous, said that on March 1, possibly up to 4,300 people at the Oakland Coliseum received just .2 mL of the Pfizer vaccine, instead of the recommended dosage of .3 mL.

The change was due to the syringes that were sent by the federal government to the Coliseum site that day and which is being run by the California Office of Emergency Services and the Federal Emergency Management Agency.

It was only on March 1 that they received these orange-capped syringes, which held .3 mL of fluid in the syringe and about .1 mL in the needle reservoir. The healthcare workers didn't notice the issue until about 2 p.m. that day, one EMT said.

He said they tested this out with other syringes and discovered that if you pulled back on the plunger, there was still between .05 mL and .1 mL of vaccine leftover after administration.

Once the healthcare workers noticed that problem, they figured out a solution to remedy the vaccine left behind. 

They began filling up the syringes to .4 mL, according to the EMTs, so that people would be getting the full amount of .3 mL. 

The EMTs also said they had been using another type of more expensive syringe with a spring loader that administers the full vaccines. As of this week, the EMTs said both types of syringes were being used.

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Cal OES spokesman Brian Ferguson told KTVU earlier in the week that as long as someone got half the recommended Pfizer vaccine, they were not considered "formally underdosed."

Some infectious disease specialists had questions about that assertion earlier in the week, including Dr. John Swartzberg, UC Berkeley public health clinical professor emeritus of infectious diseases and vaccinology.

But on Saturday, Swartzberg said he had pored over the literature and concluded that people "should be fine" as long as they get their second dose of the vaccine.

He added the caveat that there are no studies yet to positively conclude this, but all indications are that the assessments made by the Department of Health, Cal OES and Pfizer, in consultation with the federal government, are likely accurate.

Many people expressed their fears directly to KTVU following the report, and several also reached out to Swartzberg. Everyone was concerned that the vaccines they received wouldn't work.

Swartzberg noted how emotional an issue this is for people who have been shuttered in their homes for nearly a year. He, too, got tears in his eyes when he got vaccinated recently. 

And while he didn't like that people felt panicked, he also said it was important for the government and scientists to be transparent, so that people can make informed decisions about their own health. 

To reach the California Department of Health, visit or call the COVID-19 call center at (833) 422-4255. The call center is open seven days a week, 8 a.m. – 8 a.m. – 8 p.m. Monday-Friday and 8 a.m. – 5 p.m. Saturday & Sunday. 

Lisa Fernandez is a reporter for KTVU. Email Lisa at or call her at 510-874-0139. Or follow her on Twitter @ljfernandez