18-month longitudinal SARS COV-2 neutralizing antibody dynamics in haemodialysis patients receiving heterologous...

Area of Science:

• Immunology
• Virology
• Nephrology

Background:

• Patients undergoing hemodialysis (HD) have a higher risk of severe COVID-19 outcomes.
• Initial studies showed diminished immune responses to two-dose COVID-19 vaccination in HD patients.
• This study investigates the effectiveness of a three-dose heterologous vaccination strategy in HD patients.

Purpose of the Study:

• To evaluate the seroconversion rate and neutralizing antibody (nAB) levels after three-dose COVID-19 vaccination in HD patients.
• To compare antibody dynamics in HD patients versus healthy controls.
• To identify patient factors associated with antibody levels post-vaccination.

Main Methods:

• A case-control longitudinal study involving 74 HD patients and 37 healthy controls.
• Participants received a two-dose AZD1222 vaccination followed by a third BNT162b2 dose.
• Neutralizing antibody levels were measured using a pseudoviral neutralization assay at multiple time points.

Main Results:

• While two doses yielded lower antibody levels in HD patients compared to controls, a third dose significantly improved responses.
• Seroconversion rates and antibody levels in HD patients approached those of healthy controls after the third dose and remained high at 12 months.
• Younger HD patients (under 60) were more likely to maintain seropositivity at 4 months post-second dose.

Conclusions:

• A three-dose heterologous COVID-19 vaccination regimen effectively enhances and sustains neutralizing antibody levels in hemodialysis patients.
• The immune response in HD patients following three doses becomes comparable to healthy individuals, with long-lasting antibody detection.
• This vaccination strategy offers robust protection for vulnerable HD populations.