Abstract
Background
We studied whether comorbid conditions impact strength and duration of immune responses after SARS-CoV-2 mRNA vaccination in a US-based, adult population.
Methods
Sera (pre-and-post-BNT162b2 vaccination) were tested serially up to 6 months after two doses of vaccine for SARS-CoV-2-anti-Spike neutralizing capacity by pseudotyping assay in 91 Veterans and 33 healthcare workers; neutralizing titers were correlated to clinical variables with multivariate regression. In 36 participants, post-booster effect was measured.
Results
After completion of the primary vaccine series, neutralizing antibody IC-50 titers were high at one month (14-fold increase from pre-vaccination), declined at six months (3.3-fold increase), and increased at one month post-booster (52.5-fold increase). Age >65 years (β=-0.94, p=0.001) and malignancy (β=-0.88, p=0.002) significantly reduced strength of response at 1 month. Both strength and durability of response at 6 months, respectively, were negatively impacted by end-stage renal disease [(β=-1.10, p=0.004); (β=-0.66, p=0.014)], diabetes mellitus [(β=-0.57, p=0.032); (β=-0.44, p=0.028)], and systemic steroid use [(β=-0.066, p=0.032); (β=-0.55, p=0.037)]. Interestingly, the booster neutralizing antibody titer response was unaffected by clinical factors.
Conclusion
Multiple clinical factors impacted the strength and duration of post-vaccination serum neutralizing antibodies in this adult population. Response to the booster dose was universally robust, however. This suggests that the antibody response to the booster dose benefits from a sustained and effective anti-Spike memory immune response.
Full Text Availability
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