SAN DIEGO (NewsNation Now) – Allergic reactions to the COVID-19 vaccine are rare but one San Diego woman was one of the unlucky ones after receiving her inoculation.

“My husband was hesitant at first about getting the shot so I convinced him, since we’re both seniors, that we should go get the shot,” Cheryl Brennan told NewsNation affiliate KSWB.

Brennan was one of up to ten people who had suspected allergic reactions last week after getting vaccines at Petco Park, the home of the San Diego Padres, reported KSWB.

At mega-sites like stadiums and amusement parks, California health officials plan to vaccinate as many as 12,000 people a day. People stay in their vehicles to get the vaccine and can drive away after 15 minutes of observation unless the recipient suffers from allergies— then there is a 30 minute observation period.

“At 18 minutes, it was like my throat started closing,” she said, adding that with a quick wave and honk of the horn, help came right away. “My blood pressure went to 185 over 125, which I guess is very life-threatening. … They hooked up electrodes. They put ice packs on me. I had four EMTs and two nurses helping me and they brought my blood pressure back down within 45 minutes.”

UC San Diego Health began administering some vaccines to San Diegans 65 and older last week following new guidance from the federal government. The county is expected to start later this month.

The reactions prompted an investigation and providers statewide were instructed to set aside 330,000 Moderna doses on Sunday associated with the lot. Moderna released a statement that the company is “unaware of comparable clusters of adverse events from other vaccination centers which may have administered vaccines from the same lot.”

On Wednesday, the state Department of Public Health released the pulled doses after concluding it was safe to immediately begin use of the Moderna vaccines related to the batch.

After a safety review and consultation with Moderna and health agencies, the state “found no scientific basis to continue the pause” and said vaccinations can “immediately resume,” state epidemiologist Dr. Erica Pan said in a statement.

“These findings should continue to give Californians confidence that vaccines are safe and effective, and that the systems put in place to ensure vaccine safety are rigorous and science-based,” Pan said, adding that some of her family members had received it.

Dr. William Tseng specializes in internal medicine at Kaiser Permanente. Tseng said allergic reactions to the vaccine are extremely rare, roughly 1 out of a 100,000.

“The most common reactions people get are reactogenic,” Dr. Tseng said. “They come in, they get very excited, they want to get the vaccine. When they get it, they may have higher heart rate or higher blood pressure and they can feel this nausea sensation … most likely it’s from the anxiety associated with getting the vaccine.”

Dr. Tseng said many people will have a red or swollen area on the arm around the area they got the vaccine, but that’s about it.

Brennan said she’s allergic to shellfish. Since sharing her story on a Facebook page, other people with allergies have contacted her asking if the vaccine is safe. She said she won’t hesitate to get her second dose next month.

“I will still absolutely, positively go,” she said. “My opinion, if I get COVID, I would probably have a lot worse reactions than just having those issues … And my husband has underlying health conditions, so it’s worth taking that chance.”

Brennan said she wanted to share her story to highlight the team at UCSD Health who reacted quickly and had her symptoms under control within 30 to 45 minutes.

“I was so impressed with the professionalism of UCSD Health,” she said.