COVID-19 Vaccine Efficacy in Healthcare Workers Maintains Antibody Response for Six Months After Second Dose

Strategic Insights -

A recent study conducted by researchers at Jeju National University School of Medicine in South Korea has found that a COVID-19 vaccine, specifically the BNT162b2 mRNA COVID-19 vaccine, maintains an antibody response in healthcare workers for at least six months after the second dose. The study, published in Frontiers in Immunology, analyzed the antibody levels of 249 healthcare workers who received two doses of the vaccine between March 1, 2021, and October 11, 2021.

Key Takeaways:

  • The study found that the BNT162b2 mRNA vaccine was effective in protecting healthcare personnel working in COVID-19-related departments, with 96.7% of participants having positive neutralizing antibody (nAb) levels at visit 3 and 97.5% at visit 4.
  • The mean age of the participants was 38.1 ± 9.5 years, and 58.2% were females.
  • The antibody levels of SARS-CoV-2-neutralizing antibodies (nAbs) and S protein-IgG (S-IgG) antibodies were analyzed at four times: before vaccination (visit 1), 4 weeks after the first vaccination (visit 2), 3 months after the second vaccination (visit 3), and 6 months after the second vaccination (visit 4).
  • The study found that while the level of S-IgG antibodies was maintained for 6 months after the second vaccination, nAb levels waned over this 6-month period, indicating the need for a booster vaccination in some healthcare workers 6 months after full vaccination.
  • The study suggests that further studies are needed to evaluate the need for an interval of booster vaccination after full vaccination.
  • The research was conducted by a team of researchers including Jae Hong Choi, Young Ree Kim, Sang Taek Heo, Hyunjoo Oh, Misun Kim, Hyang Ran Lee, and Jeong Rae Yoo from Jeju National University School of Medicine.

Statistics:

  • 249 healthcare workers participated in the study.
  • 982 blood samples were analyzed.
  • 96.7% of participants had positive nAb levels at visit 3.
  • 97.5% of participants had positive nAb levels at visit 4.
  • The median quantitative antibody level of S-IgG antibodies at visit 2 was 1275.1 AU/mL (IQR 755.5-2119.0), at visit 3 was 2765.9 AU/mL (IQR 1809.8-4138.4), and at visit 4 was 970.1 AU/mL (IQR 606.0-1495.9).

Sources:

  • "Healthcare Workers in South Korea Maintain a SARS-CoV-2 Antibody Response Six Months After Receiving a Second Dose of the BNT162b2 mRNA Vaccine." Frontiers in Immunology, 2022, 13.
  • NewsRx. Jeju National University School of Medicine Researchers Have Provided New Study Findings on COVID-19 (Healthcare Workers in South Korea Maintain a SARS-CoV-2 Antibody Response Six Months After Receiving a Second Dose of the BNT162b2 mRNA Vaccine). Medical Letter on the CDC & FDA. February 20, 2022; p 377.