3.3 Influenza A/H1N1 vaccination and MICA immunisation

3.3 Influenza A/H1N1 vaccination and MICA immunisation

In 2009, a novel influenza A (H1N1) virus, sharing antigenic similarity with swine influenza viruses, caused a pandemic, which has lead to a wide vaccination campaign in the United States and Europe.

Since there was no data regarding neither the immunogenicity nor the safety of Influenza A/H1N1-adjuvanted vaccine in CKD patients, we decided to measure the neutralizing antibodies against Influenza A/H1N1/2009 vaccine and to determine the seroconversion rate in sera from 21 controls, 53 haemodialyzed patients and 111 renal transplant recipients taken before and 1 month after a single dose of Pandemrix vaccine (GSK Biologicals, AS03-adjuvanted). In addition, we analyzed HLA and MICA immunisation using Luminex beads coated with recombinant HLA and MICA antigens before and 1 month after vaccination.

The geometric mean titer ratio was 38, 9 and 5 for controls, haemodialysed

patients and kidney transplant recipients, respectively (p<0.0001). The proportion

of responders was 90%, 57% and 44%, respectively (p<0.0001). In renal

transplanted patients, the frequency of HLA and MICA immunisation was similar

before and after vaccination. Only 2 patients, one haemodialyzed and one renal

transplant recipient, developed de novo anti-HLA class II antibodies. Among the

16 renal transplanted patients sensitized against MICA before vaccination

(14.4%), only 8 remained positive at 1 month after vaccination while 4 patients

developed de novo MICA antibodies. No serious event related to vaccination was

reported during the study. No AR episode was observed in transplanted patients,

2

and their kidney graft function remained stable during the 6 months after vaccination.

We concluded that Influenza A/H1N1-adjuvanted vaccine was efficient and safe

in CKD patients but as compared to healthy people, the humoral response was

poor in haemodialysed and even more in transplanted patients.