With input from Dr Monica Vasudev

1550:     Weak antibody response following first dose of mRNA COVID-19 vaccine in kidney transplant recipients

1. The burden of immunosuppression may induce a weak antibody response in kidney transplant recipients following first dose of an mRNA vaccine, noted a study published in Kidney International.
2. International recommendations on COVID-19 vaccine distribution prioritize immunocompromised patients, including kidney transplant recipients. However, the guidance was issued without inclusion of this population in vaccine clinical trials.
3. In the study, 242 kidney transplant recipients who had received the first dose of the Moderna vaccine from January 21 through January 28, 2021, were included. None of them had a history of COVID-19 diagnosis and tested negative for anti-SARS-CoV-2 antibodies on the day they were given the first dose of vaccine.  Twenty eight days after the first dose, the antibody response against the spike protein was evaluated, with titres >50 arbitrary units per mL (AU/mL) considered as a positive serology.
4. One kidney transplant recipient developed mild symptomatic COVID-19 seven days after the first dose and 26 (10.7%) kidney transplant recipients had a positive serology at 28 days after the dose.
5. The median immunoglobulin (Ig)G titre was 224 AU/mL (interquartile range 76−496 AU/mL) in seropositive kidney transplant recipients, whereas the median IgG titre in the seronegative patients was < 6.8 AU/mL.
6. Seroconverted patients had longer time from transplantation (median, 15.4 vs 5.8 years; P<0.001), had lesser odds of having received induction treatment (P< 0.001), were less likely to have received steroids (34.6% vs 61.9%, P = 0.01) and had lower level of serum creatinine (median, 104 vs 120 µmol/L;P = 0.05). 
7. This finding appears to be different from the immunocompetent individuals, who seroconverted after the first injection.
8. The study emphasizes on the need to not delay the second vaccine dose in immunocompromised patients.
9. Close surveillance must be considered to discuss the opportunity of a third dose in less responsive patients. (DG Alerts)

Dr KK Aggarwal

President CMAAO, HCFI and Past National President IMA