One of the first COVID-19 patients in California says his doctors noticed a disturbing trend: the number of antibodies in his system began diminishing, leading to worries about reinfection.
When 65-year-old Dwight Everett came home from a cruise in mid-February, he became one of the first Californians diagnosed with COVID-19.
"My doctor contacted the (Centers for Disease Control and Prevention) who contacted Ventura County Health," Everett said.
He recovered at home and has since donated his plasma four times to help boost the immunity of others. But during his last donation, his doctors noticed his antibody levels had nearly diminished.
WATCH: How to make your own face mask at home
"I thought that they would stay active for a little bit longer than what they did," Everett said.
"Over time, you can see how his antibody profile changes, and I was a bit surprised to hear that," pulmonologist Dr. George Yu said.
Yu said what he's seeing in his patient is similar to what a new study out of China shows. Researchers found COVID-19 antibodies fade at about eight weeks after recovery. This raises questions about whether the illness leads to any lasting immunity.
WATCH: What you need to know about self-isolation during a pandemic
"There are very few cases of people that have been shown to be re-infected," Yu said.
Yet, research reveals we don't have evidence to show recovered patients are protected. In Spain, where they had huge outbreaks, a large-scale study found only 5% of the population had antibodies. Sixty to 70% is needed for herd immunity.
Everett said he is not taking any chances.
"Now with this recent outbreak again, I've kind of self-secluded myself in the house again," he said.
Health officials say these findings suggest the only way we are going to achieve herd immunity is with a vaccine. Until then, Yu said we need to follow all the public health protocols. We should wear masks, wash our hands and stay apart.
"I am optimistic we will come up with a way to help everyone," he said. "But at the same time, we need to be patient, we need to protect one another."