Kozasky and his wife Gina Guglietmotti describe how he felt shortly after getting the J&J vaccine on March 31.
"When he woke up the next day, he was walking crooked," Guglietmotti said.
Kozasky said he could barely walk. His wife said he had weakness on his left side and his left eye.
"I couldn't move anything," Kozasky said.
RELATED: FDA calls for pause on Johnson & Johnson vaccine
That night he went to an emergency room and was transferred to Kaiser Permanente's Ontario Medical Center, where he remains hospitalized.
"The official diagnosis is stroke," Guglietmotti said.
Kozasky's doctors don't know if there is a connection.
In a statement they said: "We are continuing to evaluate the information shared by the FDA/CDC in the context of this patient's experience. Our initial analysis does not indicate a connection to the information shared by the CDC/FDA. We will do further evaluation as we continue to care for our patient."
Health officials say the temporary pause will give scientists time to look into the cases of six women who developed the rare blood clotting disorder days after getting the shot. One has died and another is in critical condition.
Dr. Kenneth Kim and his team at Ark Clinical Research in Long Beach tested the J&J vaccine on hundreds of patients locally.
"We did not see any of these side effects," he said.
If there is a connection, he said one theory is that the vaccine in rare instances may cause an immune response that triggers platelets to clot.
"We need to figure out whether there's a certain demographic that may be at risk," Kim said. "It seems to be younger women. But again, the data is still trickling in."
If you've received the J&J vaccine within the last 14 days, be on the lookout for symptoms such as severe headaches, leg and abdominal pain and shortness of breath.
"Two weeks after having gotten the vaccine, you're probably in the clear from this serious side effect," Kim said.
This is Kozasky's second time in the hospital. He got severe symptoms when he contracted COVID-19 back in June. This is another set back for this father of two.
"I want to work," he said. "I can't even go back to work because of this."
Again, doctors don't know if there's a connection between Kozasky's illness and the J&J vaccine. Officials say anyone who was scheduled to get one will be rescheduled to receive either a Pfizer or Moderna version. Doctors urge people to continue with their vaccination efforts.
"I think until we get the data, everyone will try to make the best recommendations," Kim said. "As a country we definitely need to stay committed to getting vaccinated because that's the only way we're gonna get out of this pandemic."