"If You Get Pfizer or Moderna, Antibodies May Decrease but Will Quickly Regenerate If Needed"

[Image source=AFP Yonhap News]

[Asia Economy Reporter Lim Chun-han] A study has found that although neutralizing antibodies in the body decrease over time after receiving a messenger ribonucleic acid (mRNA) COVID-19 vaccine, they can be quickly regenerated if needed.

On the 27th (local time), according to major foreign media, researchers from the Perelman School of Medicine at the University of Pennsylvania in the United States published a paper containing these research results on the preprint site 'bioRxiv'. The paper has not yet undergone peer review. The researchers investigated 61 individuals who received the Pfizer-BioNTech or Moderna vaccines. Among the subjects, 15 had previously been infected with COVID-19.

According to the researchers, antibodies neutralizing the receptor-binding domain (RBD) of the novel coronavirus spike protein steadily decreased starting one month after vaccination. However, the vaccine-induced novel coronavirus-specific 'memory B cell' response steadily strengthened between 3 to 6 months after vaccination.

In particular, mRNA vaccines were found to produce 'memory B cells' that have adapted to respond to variants such as Alpha, Beta, and Delta. The researchers explained, "The 'memory B cells' formed by the vaccine can rapidly trigger a new antibody response when the virus enters the body," adding, "This can significantly contribute to protective immunity when vaccinated individuals are exposed to the novel coronavirus."

The researchers also stated that mRNA vaccines form 'antigen-specific CD8+ T cells' and 'memory CD4+ T cells'. T cells are a type of white blood cell that play a crucial role in identifying and eliminating cells infected by viruses or other antigens. The researchers confirmed through this study that mRNA vaccines establish long-lasting immune memory against the novel coronavirus, and that this immune memory develops progressively over time.

John Wherry, corresponding author of the paper and director of the Immunology Institute at the University of Pennsylvania School of Medicine, said, "It is true that booster shots increase antibodies and help block the novel coronavirus for a longer period," but added, "However, our bodies have natural mechanisms that support COVID-19 defense even after antibody levels decrease."