# Immune response analysis of solid organ transplantation recipients inoculated with inactivated COVID-19 vaccine: A retrospective analysis

## TL;DR

This study found that inactivated COVID-19 vaccines are safe and effective for solid organ transplant recipients, with higher antibody levels after two doses.

## Contribution

The study provides evidence on vaccine efficacy and safety in transplant recipients, recommending at least two vaccine doses before transplantation.

## Key findings

- Antibody-positive rates were significantly lower in post-transplant recipients compared to non-transplant individuals.
- Three vaccine doses were needed to achieve significant antibody levels in transplant recipients.
- Adverse reactions in transplant recipients were mild and resolved after treatment.

## Abstract

This study aimed to evaluate the efficacy and safety of solid organ transplantation recipients inoculated with an inactivated COVID-19 vaccine.

We retrospectively analyzed the antibody levels and related adverse events of non-transplantation subjects and solid organ transplant recipients, both pre-transplantation (individuals awaiting organ transplantation) and post-transplantation (individuals who have undergone organ transplantation), who received inactivated COVID-19 vaccines from February 2021 to July 2022.

The study included 38 pre-transplantation vaccination group, 129 post-transplantation vaccination group, and 246 non-transplantation group. The antibody titer was assessed monthly within the period of 1–12 months after the last injection. The antibody-positive rate among the three groups were 36.84, 20.30, 61.17% (P < 0.05). The antibody-positive rates among three groups with one, two doses vaccine were not significantly different (P > 0.05), but were significantly different after three doses (P < 0.05). The antibody titers among three groups were significantly different after two doses (P < 0.05). Adverse reactions occurred in six transplant recipients, which were relieved after treatment, and not in the non-transplantation subjects.

Inactivated COVID-19 vaccine is safe and effective for solid organ transplantation recipients, at least two doses of which should be completed before organ transplant surgery.