The following is a summary of “Safety and Immunogenicity of the mRNA-1273 COVID-19 Vaccine in Solid Organ Transplant Recipients,” published in March 2024 issue of Infectious Diseases by Figueroa et al.

People who are Solid Organ Transplant Recipients (SOTRs) have a significant risk of poor COVID-19-related outcomes. 

Researchers conducted a prospective study evaluating the effects of mRNA-1273 in kidney and liver SOTRs along with participants with immunocompetency. 

They used a phased trial to evaluate mRNA-1273 in 234 SOTRs (137 kidney, 77 liver SOTRs, and 20 participants with immunocompetency). In part A, SOTRs received three 100-µg doses of mRNA-1273, while patients with immunocompetency only received two doses. In part B, an additional dose of 100-µg was offered ≥4 months post-primary series. 

The results showed that mRNA-1273 was well tolerated among SOTRs. Four serious adverse events linked to the vaccine were reported in 3 SOTRs. No vaccine-related organ rejection or deaths occurred. mRNA-1273 showed modest neutralizing antibody (nAb) responses post-dose 2, improving after dose 3 in SOTRs. Liver SOTRs had similar responses post-dose 3 compared to participants that are immunocompetent post-dose 2. Additional doses boosted responses in SOTRs, particularly in liver recipients (3-fold higher than post-dose 2), although remained lower than in individuals with immunocompetency. Most kidney SOTRs on multiple immunosuppressants exhibited reduced antibody responses compared to liver SOTRs.

Investigators concluded that mRNA-1273 (100µg) was well-tolerated, and doses 3 and the additional dose improved antibody responses among SOTRs. 

Source: academic.oup.com/jid/advance-article/doi/10.1093/infdis/jiae140/7633292