AUSTIN (Nexstar) — A new study by Texas researchers found that antibodies levels are higher in women and younger people than those in men after receving the COVID-19 vaccine.

The Texas Biomedical Research Institute — partnered with the University of Verona, Italy — conducted the largest study in the world on the prevalence of antibodies over time. While it’s now widely established that vaccine antibodies wane after six months, the study found specifics as to how much, and the difference age and sex plays in antibody levels.

The findings are based on a group of 787 healthcare workers in Italy, ranging in ages 21 to 75, who recieved two doses of the Pfizer COVID-19 vaccine. Their antibody levels were measured before vaccination, after the second dose, and at one, three and six months after the second shot.

Dr. Brandon Michael Henry, one of the lead scientist physicians in the study, said the research results were consistent with trends throughout the pandemic.

After six months, women and younger people tending to have higher peak levels of antibodies than men and people ages 65 and older.

“We have observed throughout the pandemic more older people and men suffer the worst consequences of COVID-19,” Henry says. “These studies point to weaker immune responses against SARS-CoV-2 as a contributing factor to this phenomenon.”

Henry said people also had different levels of various kinds of antibodies by the six month mark.

“We found the antibodies that prevent severe disease, they tend to persist. Those are the ones that dropped about 50% after six months. But when we looked at the ones that are, for example, along the respiratory tract that would help stop any type of breakthrough infection, we noticed that about at least half of people have no detectable levels of those antibodies at six months,” said Dr. Brandon Michael Henry, one of the lead scientist physicians in the study.

He said this is why those who are eligible should get the booster vaccine to decrease chances of contracting COVID-19, even after being vaccinated. Henry and other physicians emphasize, this does not mean that the COVID-19 vaccine is effective, as it is normal for immunity to wane over time.

“These vaccines do work remarkably well… we’re gonna have to booster going forward and there probably will be more vaccines coming in the future as we see more variants,” Henry said. “But they’re miracles of modern medicine. They really are preventing our hospital system of being overwhelmed, keeping people out of the hospitals, keeping you from dying and getting to see your relatives and enjoying life.”