Antibody titer before and after the third dose of SARS-CoV-2BNT162b2 vaccine in adults aged 60 years and older.

Eliakim-Raz N, Leibovici-Weisman Y, Stemmer A, et al. Antibody titers before and after the third dose of SARS-CoV-2BNT162b2 vaccine in adults aged 60 years and older. Jama. 2021; 326(21): 2203-2204. doi: 10.1001 / jama.2021.19885

Commentary

The study recruited participants aged 60 years and older at vaccination centers, with the RMC providing these to workers and their families after the third dose was approved in Israel.

The Wilcoxon signed rank test was used to evaluate the difference in IgG levels before and 10-19 days after the third dose. In addition, Spearman's correlation coefficient was used to evaluate the correlation between the IgG levels and the age of the participants.

In the 97 study participants, the median age was 70 years, and 61% were female.

Ninety-four participants (97%) were seropositive, and the median titer level increased significantly after the third dose, from a median of 440 AU/mL (IQR, 294-923) to 25 468 AU/mL (IQR, 14 203-36 618). (P <.001)

And no significant correlation was observed between age and IgG titer, and no variables were significantly associated with increased IgG titer, such as age, gender, days since first vaccination, and comorbidities. No serious adverse events were reported, according to the study.