(TJV) A San Diego, California ER nurse has tested positive for COVID-19, just eight days after receiving his first dose of the Pfizer COVID vaccine.

Dr. Christian Ramers, an infectious disease specialist involved in the vaccine rollout at the county level, told ABC 10, “It’s not unexpected at all. If you work through the numbers, this is exactly what we’d expect to happen if someone is exposed.”

Dr. Ramers notes Matthew could have had the virus before he took the vaccination, and says he knows of several other local cases where healthcare workers became infected after taking the vaccine.

“That first dose we think gives you somewhere around 50%, and you need that second dose to get up to 95%,” Dr. Ramers said.

Dr. Ramers also reminded the ABC 10 audience that even after receiving the vaccination, masks, handwashing, and other COVID protocols will still be necessary.