Kang YM, et al. J Korean Med Sci. 2021 Nov;36(46):e311. https://doi.org/10.3346/jkms.2021.36.e311

The efficacy and safety of the BNT162b2 vaccine are known, but antibodies are expected to decrease over time after vaccination. We collected blood samples from 104 fully vaccinated health care workers at 3 and 5 weeks after first vaccination and 4 months after second vaccination. Antibody titers and neutralizing antibodies were measured. In our study, both antibody titers and neutralizing antibodies increased significantly at 5 weeks after first vaccination but decreased rapidly at 4 months after second vaccination. Additionally, the results showed a significant decrease regardless of gender or age. Further studies are needed to help determine the interval of SARS-CoV-2 vaccinations.

Cho EY, et al. J Korean Med Sci. 2016 Jul;31(7):1082-1088. https://doi.org/10.3346/jkms.2016.31.7.1082

Rhie K, et al. J Korean Med Sci. 2017 Dec;33(6):e45. https://doi.org/10.3346/jkms.2018.33.e45

Rotavirus (RV) infection is the primary cause for childhood gastroenteritis worldwide. In Korea, RV infection is most common among children less than 5 y of age. This post-licensure study was conducted to further evaluate the RV vaccine (RIX4414) to provide additional local clinical data to the Korean Food and Drug Association. Healthy infants aged 6–12 weeks were enrolled to receive two doses of either RIX4414 or placebo as per 0, 1–2 mo schedule. Blood samples were collected before dose-1 and one month post-dose-2 of RIX4414/placebo to assess serum anti-RV IgA antibody concentrations using ELISA. Gastroenteritis stool samples were tested for the presence of RV using ELISA. RV positive samples were subjected to further analysis for G and P typing. Among 684 infants enrolled and vaccinated, 432 infants (RIX4414 = 318; placebo = 114) were included in the according-to-protocol cohort for immunogenicity. The anti-RV IgA antibody seroconversion rates in the RIX4414 group following one month post-dose-2 were 88.1% (95% CI: 84.0–91.4) and the corresponding geometric mean concentration in the RIX4414 group was 208.5 U/ml (95% CI: 174.2–249.5). Occurrence of solicited and unsolicited adverse events were similar in both, RIX4414 and placebo groups. None of the gastroenteritis stool samples tested positive for RV and no fatal SAEs were reported in either groups. The two-dose regimen of RIX4414 was observed to be immunogenic with a similar safety profile as compared with the placebo group, when administered to healthy Korean infants.

Song SH, et al. J Korean Med Sci. 2023 Apr;38(16):e127. https://doi.org/10.3346/jkms.2023.38.e127