UTSW researchers’ findings suggest that COVID-19 boosters and updated vaccines are more important for older adults, who are more susceptible to severe illness with the virus. Photo credit: Getty Images
DALLAS – Nov. 29, 2022 – The Pfizer-BioNTech COVID-19 vaccine limits transmission, hospitalization, and death from COVID-19 even among patients infected by variants of the virus, but the effectiveness of antibodies it generates diminishes as patients get older, according to a study by UT Southwestern researchers.
Lenette Lu, M.D., Ph.D.
“The fact that these antibody functions decrease with age is one reason why the elderly are still more susceptible to severe illness with COVID-19 and highlights the need to develop different approaches for older, vulnerable individuals,” said Lenette Lu, M.D., Ph.D., Assistant Professor of Internal Medicine and Immunology in the Division of Infectious Diseases and Geographic Medicine, and lead author of the paper published in Cell Reports.
The vaccine, approved by the U.S. Food and Drug Administration in August 2021, contains a piece of mRNA encoding the SARS-CoV-2 spike protein, which the virus uses to infect human cells. Initial studies of the vaccine focused on how it led to the generation of antibodies that could prevent SARS-CoV-2 from entering cells, neutralizing the virus before it could cause disease.
The emergence of new variants, including Delta and Omicron, left the vaccine less effective at neutralizing SARS-CoV-2 and resulted in increased rates of infection. However, vaccinated individuals, even when infected with COVID-19, continued to be protected against severe disease and death.
To understand how vaccines protect people without completely neutralizing the virus, blood samples were analyzed from 51 adults, ranging in age from 21 to 82, who had not been infected previously with COVID-19 and who each received two doses of the Pfizer-BioNTech vaccine between December 2020 and February 2021. From the samples, the researchers isolated antibodies specific to the SARS-CoV-2 spike protein.