T cell reactivity to the SARS-CoV-2 Omicron variant is preserved in most but not all individuals.

The SARS-CoV-2 Omicron variant (B.1.1.529) contains mutations that mediate escape from antibody responses, although the extent to which these substitutions in spike and non-spike proteins affect T cell recognition is unknown. In this study, we show that T cell responses in individuals with prior infection, vaccination, both prior infection and vaccination, and boosted vaccination are largely preserved to Omicron spike and non-spike proteins. However, we also identify a subset of individuals (∼21%) with a >50% reduction in T cell reactivity to the Omicron spike. Evaluation of functional CD4+ and CD8+ memory T cell responses confirmed these findings and revealed that reduced recognition to Omicron spike is primarily observed within the CD8+ T cell compartment potentially due to escape from HLA binding. Booster vaccination enhanced T cell responses to Omicron spike. In contrast to neutralizing immunity, these findings suggest preservation of T cell responses to the Omicron variant, although with reduced reactivity in some individuals.

mRNA-based COVID-19 vaccine boosters induce neutralizing immunity against SARS-CoV-2 Omicron variant.

Recent surveillance has revealed the emergence of the SARS-CoV-2 Omicron variant (BA.1/B.1.1.529) harboring up to 36 mutations in spike protein, the target of neutralizing antibodies. Given its potential to escape vaccine-induced humoral immunity, we measured the neutralization potency of sera from 88 mRNA-1273, 111 BNT162b, and 40 Ad26.COV2.S vaccine recipients against wild-type, Delta, and Omicron SARS-CoV-2 pseudoviruses. We included individuals that received their primary series recently (<3 months), distantly (6-12 months), or an additional "booster" dose, while accounting for prior SARS-CoV-2 infection. Remarkably, neutralization of Omicron was undetectable in most vaccinees. However, individuals boosted with mRNA vaccines exhibited potent neutralization of Omicron, only 4-6-fold lower than wild type, suggesting enhanced cross-reactivity of neutralizing antibody responses. In addition, we find that Omicron pseudovirus infects more efficiently than other variants tested. Overall, this study highlights the importance of additional mRNA doses to broaden neutralizing antibody responses against highly divergent SARS-CoV-2 variants.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine response in adults with predominantly antibody deficiency.

Background: Patients with predominantly antibody deficiency (PAD) have lower anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike antibody levels after initial 2-dose SARS-CoV-2 vaccination than healthy controls do; however, the anti-spike antibody responses and neutralization function in patients with PAD following subsequent immunizations remain understudied. Objective: We sought to characterize anti-spike antibody responses in adults with PAD over the course of 5 SARS-CoV-2 vaccine doses and identify diagnostic and immunophenotypic risk factors for low antibody response. Methods: We evaluated anti-spike antibody levels in 117 adult patients with PAD and 192 adult healthy controls following a maximum of 5 SARS-CoV-2 immunizations. We assessed neutralization of the SARS-CoV-2 wild-type strain and the Omicron BA.5 variant and analyzed infection outcomes. Results: The patients with PAD had significantly lower mean anti-spike antibody levels after 3 SARS-CoV-2 vaccine doses than the healthy controls did (1,439.1 vs 21,890.4 U/mL [P < .0001]). Adults with secondary PAD, severe primary PAD, and high-risk immunophenotypes had lower mean anti-spike antibody levels following vaccine doses 2, 3, and/or 4 but not following vaccine dose 5. Compared with patients with mild and moderate PAD, patients with severe PAD had a higher rate of increase in anti-spike antibody levels over 5 immunizations. A strong positive correlation was observed between anti-spike antibody levels and neutralization of both the SARS-CoV-2 wild-type strain and the Omicron BA.5 variant. Most infections were managed on an outpatient basis. Conclusions: In all of the patients with PAD, anti-spike antibody levels increased with successive SARS-CoV-2 immunizations and were correlated with neutralization of both the SARS-CoV-2 wild-type strain and the Omicron BA.5 variant. Secondary PAD, severe primary PAD, and high-risk immunophenotypes were correlated with lower mean anti-spike antibody levels following vaccine doses 2 through 4. Patients with severe PAD had the highest rate of increase in anti-spike antibody levels over 5 immunizations. These data suggest a clinical benefit to sequential SARS-CoV-2 immunizations, particularly among high-risk patients with PAD.

T cell reactivity to the SARS-CoV-2 Omicron variant is preserved in most but not all prior infected and vaccinated individuals.

The SARS-CoV-2 Omicron variant (B.1.1.529) contains mutations that mediate escape from infection and vaccine-induced antibody responses, although the extent to which these substitutions in spike and non-spike proteins affect T cell recognition is unknown. Here we show that T cell responses in individuals with prior infection, vaccination, both prior infection and vaccination, and boosted vaccination are largely preserved to Omicron spike and non-spike proteins. However, we also identify a subset of individuals (∻21%) with a >50% reduction in T cell reactivity to the Omicron spike. Evaluation of functional CD4 + and CD8 + memory T cell responses confirmed these findings and reveal that reduced recognition to Omicron spike is primarily observed within the CD8 + T cell compartment. Booster vaccination substantially enhanced T cell responses to Omicron spike. In contrast to neutralizing immunity, these findings suggest preservation of T cell responses to the Omicron variant, although with reduced reactivity in some individuals.

Response to Severe Acute Respiratory Syndrome Coronavirus 2 Initial Series and Additional Dose Vaccine in Patients With Predominant Antibody Deficiency.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with predominant antibody deficiency (PAD) is associated with high morbidity, yet data regarding the response to SARS-CoV-2 immunization in PAD patients, including additional dose vaccine, are limited. OBJECTIVE: To characterize antibody response to SARS-CoV-2 vaccine in PAD patients and define correlates of vaccine response. METHODS: We assessed the levels and function of anti-SARS-CoV-2 antibodies in 62 PAD patients compared with matched healthy controls at baseline, at 4 to 6 weeks after the initial series of immunization (a single dose of Ad26.COV2.S [Janssen] or two doses of BNT162b2 [Pfizer-BioNTech] or mRNA-1273 [Moderna]), and at 4 to 6 weeks after an additional dose immunization, if received. RESULTS: After the initial series of SARS-CoV-2 vaccination, PAD patients had lower mean anti-spike antibody levels compared with matched healthy controls (140.1 vs 547.3 U/mL; P = .02). Patients with secondary PAD (eg, B-cell depletion therapy was used) and those with severe primary PAD (eg, common variable immunodeficiency with autoinflammatory complications) had the lowest mean anti-spike antibody levels. Immune correlates of a low anti-spike antibody response included low CD4+ T helper cells, low CD19+ total B cells, and low class-switched memory (CD27+IgD/M-) B cells. In addition, a low (<100 U/mL) anti-spike antibody response was associated with prior exposure to B-cell depletion therapy, both at any time in the past (odds ratio = 5.5; confidence interval, 1.5-20.4; P = .01) and proximal to vaccination (odds ratio = 36.4; confidence interval, 1.7-791.9; P = .02). Additional dose immunization with an mRNA vaccine in a subset of 31 PAD patients increased mean anti-spike antibody levels (76.3 U/mL before to 1065 U/mL after the additional dose; P < .0001). CONCLUSIONS: Patients with secondary and severe primary PAD, characterized by low T helper cells, low B cells, and/or low class-switched memory B cells, were at risk for low antibody response to SARS-CoV-2 immunization, which improved after an additional dose vaccination in most patients.

mRNA-based COVID-19 vaccine boosters induce neutralizing immunity against SARS-CoV-2 Omicron variant.

Recent surveillance has revealed the emergence of the SARS-CoV-2 Omicron variant (BA.1/B.1.1.529) harboring up to 36 mutations in spike protein, the target of vaccine-induced neutralizing antibodies. Given its potential to escape vaccine-induced humoral immunity, we measured neutralization potency of sera from 88 mRNA-1273, 111 BNT162b, and 40 Ad26.COV2.S vaccine recipients against wild type, Delta, and Omicron SARS-CoV-2 pseudoviruses. We included individuals that were vaccinated recently (<3 months), distantly (6-12 months), or recently boosted, and accounted for prior SARS-CoV-2 infection. Remarkably, neutralization of Omicron was undetectable in most vaccinated individuals. However, individuals boosted with mRNA vaccines exhibited potent neutralization of Omicron only 4-6-fold lower than wild type, suggesting that boosters enhance the cross-reactivity of neutralizing antibody responses. In addition, we find Omicron pseudovirus is more infectious than any other variant tested. Overall, this study highlights the importance of boosters to broaden neutralizing antibody responses against highly divergent SARS-CoV-2 variants.

Study by XPS and UV-visible and DRIFT spectroscopies of electropolymerized films of substituted Ni(II)-p-phenylporphyrins and -phthalocyanines.

Films of nickel tetrasulfophthalocyanine and - p-phenylporphyrin (NiTSPc and NiTSPP, respectively) were obtained by repetitive cyclic voltammetry (RCV) of the 1 mM complex in aqueous solution, while films of the water-insoluble nickel tetraaminophthalocyanine and - p-phenylporphyrin (NiTAPc and NiTAPP, respectively) had to be obtained by RCV of the 1 mM complex in organic solvents. Glassy carbon (GC), ITO, or platinum electrodes were used as substrates. The modified electrodes were characterized by cyclic voltammetry (CV) and UV-visible, infrared, and X-ray photoelectron spectroscopies. The CVs of the sulfo films showed the characteristic peaks of the Ni(II)/Ni(III) process, whereas the CVs of the amino films did not, very small Ni(II)/Ni(III) peaks appearing only after activation by RCV. Upon oxidation to Ni(III) both sulfo films changed from transparent to dark violet. The IR spectra of the polyNiTSPP and the polyNiTSPc films showed bands at 3628 cm (-1) and 3500 cm (-1), respectively, which could be due to interstitial water molecules occluded during the polymerization. The Ni 2p XP spectra indicate that the magnetic character of the Ni(II) ions in NiTSPP is dramatically changed by the polymerization, from diamagnetic in the monomer to paramagnetic in the polymeric film, indicating the formation of Ni-O-Ni bridges or of clusters of Ni(OH) 2. On the contrary, the Ni 2p XP spectra of the unactivated NiTAPP film, in which the Ni(II)/Ni(III) process was absent, showed only diamagnetic Ni(II). Therefore, it is concluded that only paramagnetic Ni(II) ions can be electrooxidized to Ni(III).

Theoretical and spectroscopic study of nickel(II) porphyrin derivatives.

A set of substituted (sulfonate, amino) nickel porphyrin derivatives such as phthalocyanine and phenylporphyrin was studied by spectroscopic (UV-vis, FTIR, XPS) and quantum-chemical methods. The Q and Soret bands were identified in the UV-vis spectra of aquo solutions of the tetrasulfo-substituted complexes and in DMF and ACN solutions of the amino-substituted phenylporphyrin and phthalocyanine Ni(II) complexes, respectively. In all the complexes the frontier molecular orbitals predict that the oxidation and reduction sites are localized on the ligand rather than in the metal atom. A natural bonding orbital (NBO) analysis of all the complexes showed that a two-center bond NBO between the pyrrolic nitrogens (Npyrr) and the nickel atom does not exist, the Npyrr...Ni interaction occurring instead by a delocalization from one lone pair of each Npyrr toward one lone pair of the nickel atom, as estimated by second-order perturbation theory. The calculated values of electronic transitions between the frontier molecular orbitals are in good agreeement with the UV-vis data. At the theoretical level, we found that while the ligand effect is more important in the Q-band (approximately 16 kcal/mol), the substituent effect is more significant in the Soret band (approximately 9 kcal/mol). A good agreement was also found between the experimental and calculated infrared spectra, which allowed the assignment of many experimental bands. The XPS results indicate that the Ni(II) present in the phenylporphyrin structure is not affected by a change of the substituent (sulfonate or amino).