Faculty Bibliography

The increasing prevalence of SARS-CoV-2 variants has raised concerns regarding possible decreases in vaccine effectiveness. Here, neutralizing antibody titers elicited by mRNA-based and adenoviral vector-based vaccines against variant pseudotyped viruses were measured. BNT162b2 and mRNA-1273-elicited antibodies showed modest neutralization resistance against Beta, Delta, Delta plus and Lambda variants whereas Ad26.COV2.S-elicited antibodies from a significant fraction of vaccinated individuals had less neutralizing titer (IC₅₀ <50). The data underscore the importance of surveillance for breakthrough infections that result in severe COVID-19 and suggest a potential benefit by second immunization following Ad26.COV2.S to increase protection from current and future variants.

Recently identified severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants Mu and C.1.2 have spike proteins with mutations that may confer resistance to natural and vaccine-elicited antibodies. Analysis of neutralizing antibody titers in the sera of vaccinated individuals without previous history of infection and from convalescent individuals show partial resistance of the viruses. In contrast, sera from individuals with a previous history of SARS-CoV-2 infection who were subsequently vaccinated neutralize variants with titers 4- to 11-fold higher, providing a rationale for vaccination of individuals with previous infection. The heavily mutated C.1.2 spike is the most antibody neutralization-resistant spike to date; however, the avidity of C.1.2 spike protein for angiotensin-converting enzyme 2 (ACE2) is low. This finding suggests that the virus evolved to escape the humoral response but has a decrease in fitness, suggesting that it may cause milder disease or be less transmissible. It may be difficult for the spike protein to evolve to escape neutralizing antibodies while maintaining high affinity for ACE2.

[Figure: see text].

SARS-CoV-2 mRNA vaccines have shown remarkable clinical efficacy, but questions remain about the nature and kinetics of T cell priming. We performed longitudinal antigen-specific T cell analyses on healthy SARS-CoV-2-naive and recovered individuals prior to and following mRNA prime and boost vaccination. Vaccination induced rapid antigen-specific CD4⁺ T cell responses in naive subjects after the first dose, whereas CD8⁺ T cell responses developed gradually and were variable in magnitude. Vaccine-induced Th1 and Tfh cell responses following the first dose correlated with post-boost CD8⁺ T cells and neutralizing antibodies, respectively. Integrated analysis revealed coordinated immune responses with distinct trajectories in SARS-CoV-2-naive and recovered individuals. Last, whereas booster vaccination improved T cell responses in SARS-CoV-2-naive subjects, the second dose had little effect in SARS-CoV-2-recovered individuals. These findings highlight the role of rapidly primed CD4⁺ T cells in coordinating responses to the second vaccine dose in SARS-CoV-2-naive individuals.

Background/Purpose: Patients with immune mediated inflammatory disorders (IMIDs) have an inherently heightened susceptibility to infection and may be considered high risk for developing COVID-19. While data regarding the COVID-19 vaccine's immunogenicity in an immunocompetent adult population is rapidly emerging, the ability of IMID patients to adequately respond to these vaccines is not known. Here, we investigate the humoral and cellular immune response to mRNA COVID-19 vaccines in patients with IMIDs on immunomodulatory treatment Methods: Patients with immune mediated inflammatory disorders (IMIDs) have an inherently heightened susceptibility to infection and may be considered high risk for developing COVID-19. While data regarding the COVID-19 vaccine's immunogenicity in an immunocompetent adult population is rapidly emerging, the ability of IMID patients to adequately respond to these vaccines is not known. Here, we investigate the humoral and cellular immune response to mRNA COVID-19 vaccines in patients with IMIDs on immunomodulatory treatment.
Result(s): The NY cohort baseline characteristics are found in Table 1. The Erlangen cohort consisted of 182 healthy subjects, 11 subjects with IMID receiving TNFi monotherapy, and 20 subjects with IMID on MTX monotherapy. In both cohorts, healthy individuals and those with IMID not on MTX were similar in age, while those IMID patients receiving MTX were generally older. In the NY cohort, of the healthy participants, 96.3% demonstrated adequate humoral immune response. Patients with IMID not on MTX achieved a similar rate of high antibody response rate (91.8%), while those on MTX had a lower rate of adequate humoral response (75.0%) (Figure 1A). This remains true even after the exclusion of patients who had evidence of prior COVID-19 infection (P= 0.014). Of note, 3 out of the 4 IMID patients receiving rituximab did not produce an adequate response. Similarly, in the Erlangen validation cohort, 98.3% of healthy controls, 90.9% of patients with IMID receiving TNFi monotherapy, and 50.0% receiving MTX monotherapy achieved adequate immunogenicity (Figure 1B). These differences remain significant when combining the cohorts, using a stricter definition of adequate response, and in a subgroup analysis by age. Cellular response was also analyzed in a subgroup of the NY cohort before and after second vaccination. Activated CD8+ T cells (CD8+ T cells expressing Ki67 and CD38) and the granzyme B-producing subset of these activated CD8+ T cells, were induced in immunocompetent adults and those with IMID not on MTX, but not induced in patients receiving MTX (Figure 2).
Conclusion(s): In two independent cohorts of IMID patients, MTX, a widely used immunomodulator for the treatment of several IMIDs, adversely affected humoral and cellular immune response to COVID-19 mRNA vaccines. Although precise cut offs for immunogenicity that correlate with vaccine efficacy are yet to be established, our findings suggest that different strategies may need to be explored in patients with IMID taking MTX to increase the chances of immunization efficacy against SARS-CoV-2, as has been demonstrated for other viral vaccines

The increasing prevalence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants with spike protein mutations raises concerns that antibodies elicited by natural infection or vaccination and therapeutic monoclonal antibodies will become less effective. We show that convalescent-phase sera neutralize pseudotyped viruses with the B.1.1.7, B.1.351, B.1.1.248, COH.20G/677H, 20A.EU2, and mink cluster 5 spike proteins with only a minor loss in titer. Similarly, antibodies elicited by Pfizer BNT162b2 vaccination neutralized B.1.351 and B.1.1.248 with only a 3-fold decrease in titer, an effect attributable to E484K. Analysis of the Regeneron monoclonal antibodies REGN10933 and REGN10987 showed that REGN10933 has lost neutralizing activity against the B.1.351 and B.1.1.248 pseudotyped viruses, and the cocktail is 9- to 15-fold decreased in titer. These findings suggest that antibodies elicited by natural infection and by the Pfizer vaccine will maintain protection against the B.1.1.7, B.1.351, and B.1.1.248 variants but that monoclonal antibody therapy may be less effective for patients infected with B.1.351 or B.1.1.248 SARS-CoV-2. IMPORTANCE The rapid evolution of SARS-CoV-2 variants has raised concerns with regard to their potential to escape from vaccine-elicited antibodies and anti-spike protein monoclonal antibodies. We report here on an analysis of sera from recovered patients and vaccinated individuals and on neutralization by Regeneron therapeutic monoclonal antibodies. Overall, the variants were neutralized nearly as well as the wild-type pseudotyped virus. The B.1.351 variant was somewhat resistant to vaccine-elicited antibodies but was still readily neutralized. One of the two Regeneron therapeutic monoclonal antibodies seems to have lost most of its activity against the B.1.351 variant, raising concerns that the combination therapy might be less effective for some patients. The findings should alleviate concerns that vaccines will become ineffective but suggest the importance of continued surveillance for potential new variants.

Humoral immune responses are dysregulated with aging, but the cellular and molecular pathways involved remain incompletely understood. In particular, little is known about the effects of aging on T follicular helper (Tfh) CD4 cells, the key cells that provide help to B cells for effective humoral immunity. We performed transcriptional profiling and cellular analysis on circulating Tfh before and after influenza vaccination in young and elderly adults. First, whole-blood transcriptional profiling shows that ICOS⁺CD38⁺ cTfh following vaccination preferentially enriches in gene sets associated with youth versus aging compared to other circulating T cell types. Second, vaccine-induced ICOS⁺CD38⁺ cTfh from the elderly had increased the expression of genes associated with inflammation, including tumor necrosis factor-nuclear factor κB (TNF-NF-κB) pathway activation. Finally, vaccine-induced ICOS⁺CD38⁺ cTfh display strong enrichment for signatures of underlying age-associated biological changes. These data highlight the ability to use vaccine-induced cTfh as cellular "biosensors" of underlying inflammatory and/or overall immune health.