, according to a new retrospective analysis. The link is particularly strong among B-cell depleting drugs.
“A lot of patients ask us if having MS by itself affects the vaccine response. We did not find that, but it’s about the disease-modifying therapy that a patient is being treated with,” Tirisham Gyang, MD, said in an interview. Dr. Gyang presented the study at a poster session during the annual meeting held by the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS).
“These patients (on DMTs) had decreased neutralizing antibody levels to the vaccine after they received it. We also saw a similar marker in drugs that modulate the sphingosine S-1 receptor. These patients also had a lower titer. It wasn’t statistically significant, but we think it’s positive. It was underpowered because there was a small number of patients in that subgroup,” said Dr. Gyang, assistant professor of neurology at The Ohio State University.
The results can inform vaccine strategies among people with MS, but the issue remains complex. “I don’t know that we could do a blanket statement and say, if you wait this amount of time, everybody will be okay. It’s a very individualized approach, and patients need to discuss timing of vaccines with their providers, because we know that waiting is better. It’s preferable to wait until towards the end of the dosing cycle. The other factor is making sure that the MS is well treated,” said Dr. Gyang.
The researchers prospectively followed 83 MS patients at the The Ohio State University Wexner Medical Center. Among the cohort, 71% were female. Fifty-one subjects had serum samples analyzed following mRNA COVID-19 vaccination, and they were compared with 38 health care worker controls.
After vaccination, people with MS had about 2.4-fold lower levels of half-maximal neutralization titer (NT50) values compared with health care worker controls. This appeared to be driven primarily by DMTs. There was a more than ninefold reduction in the neutralizing antibody (nAb) response among 13 patients on B-cell depleting agents, compared with no therapy or other therapies (P < .001). Among of individuals on these agents, 61.5% had no detectable nAb.
The researchers also found an association between postvaccine NT50 values and when the vaccine was received compared with the last infusion of B-cell depleting agents. Every additional day since the previous infusion was associated with a 3.7% increase in NT50 value (P = .0032).
The average length of exposure to B-cell depleting agents was 24 months and the median was 25 months. There was no association between length of time on a B-cell depleting agent and NT50 values after vaccination (Spearman correlation 0.35, P = .24).
Subanalyses by sex and vaccine type revealed no differences in nAb levels.
The study did not look at T-cell responses after vaccination or the effect of T-cell depleting agents, and T cells likely still provide some protection, according to Dr. Gyang. “Even though the vaccine response may not be as robust as it would have been if they were not on the drug, there is still some degree of protection,” she said.