New study offers key to further protection against COVID-19

Texas Biomed tracked waning antibodies by gender, age, time

SAN ANTONIO – In the largest study of its kind, Texas Biomedical Research Institute in San Antonio tracked waning antibodies against COVID-19 by gender, age and time.

Dr. Brandon Michael Henry, a physician scientist and the postdoctoral researcher who co-led the study, said it tested patients’ antibody levels before their first and second doses of the vaccine, after one month, two months and six months after being vaccinated.

“We have this really nice timeline of each individual and how the antibodies actually behave,” Henry said.

Henry said after six months, all of the patients saw a 50% decrease in lifesaving antibodies.

Yet he said, “Women tend to have higher antibody levels in men, and that’s consistent regardless of age” and they tend to have “slightly better outcomes than men because they tend to have slightly better immune responses.”

He said one reason for that is, “Estrogen tends to have a pro-inflammatory aspect that helps boost antiviral responses where testosterone tends to be immunosuppressive.”

The study also showed those who had COVID-19 or were exposed to COVID-19 before being vaccinated showed a faster decline in antibodies.

Henry said that reinforces why everyone should be vaccinated and get their booster shots.

Without the booster shot, Henry said, “We project most individuals will have no detectable antibodies in 16 to 19 months.”

But he said now that the CDC has approved booster shots for all adults over age 18, they now have the opportunity to get the added protection they need.

Anita Kurian, Metro Health assistant director, said it will now expand boosters at its Alamodome mass vaccination site, open from noon to 8 p.m. Wed.-Fri., and at vaccine pop-up clinics which are listed at or by calling 311.

“Metro Health has plenty of vaccine supply available to provide booster doses to all of our residents,” Kurian said.

About the Authors:

Jessie Degollado has been with KSAT since 1984. She is a general assignments reporter who covers a wide variety of stories. Raised in Laredo and as an anchor/reporter at KRGV in the Rio Grande Valley, Jessie is especially familiar with border and immigration issues. In 2007, Jessie also was inducted into the San Antonio Women's Hall of Fame.

Luis Cienfuegos is a photographer at KSAT 12.