Long term follow-up of humoral and cellular response to mRNA-based vaccines for SARS-CoV-2 in patients with active multiple myeloma

Follow-up of humoral and cellular immune responses after the third SARS-CoV-2 vaccine dose in multiple myeloma patients

The stability of immune responses to SARS-CoV-2 vaccines, especially concerning the cross-reactive recognition of the Omicron variant, remains incompletely characterized in multiple myeloma (MM) patients. This study evaluated humoral responses in 29 MM patients and cellular responses in a subset of 19 MM patients, specific to Wuhan and Omicron spike proteins, between 16 and 26 weeks following the third vaccine dose. After 26 weeks, we highlighted a significant reduction in the neutralizing antibodies to both spikes and the percentages of IFN-γ+CD107a+ spike-specific CD8+ T cells. On the other hand, patients who underwent an additional stimulation between the two time points, through either a fourth vaccine dose or breakthrough infection, showed a significant increase in neutralizing antibodies and stable levels of cytotoxic CD8+ T cells. Additionally, those with only three doses experienced a higher rate of breakthrough infections during the 32-week follow-up period. These findings underscore the waning of vaccine-induced immunity over time and may help benefit-risk evaluation in vaccination strategies in MM patients.

One Year Duration of Immune Response Following a 3rd Booster Dose of mRNA Vaccine Against COVID-19 in 292 Patients With Hematological Malignancies in University Hospital Ostrava, Czech Republic

AIMS

To evaluate antibody response to mRNA vaccine, identify subgroups with poor response and to determine long-term antibody durability in hematological patients.

MATERIALS AND METHODS

We have vaccinated 292 patients with all hematological malignancies with a third dose of mRNA COMIRNATY vaccine with a 12-month follow-up period in our center in Ostrava, Czech Republic.

RESULTS

Antibody response for the whole cohort exceeded 74% through the whole 12-month follow-up. Lowest seroconversion was observed in CLL cohort (20/41, 48.8%), patients who received anti-CD20 therapy < 6 months before vaccination (8/30, 26.7%) and BTK inhibitors (3/6, 50.0%). On the contrary, patients with chronic myeloproliferative neoplasms and acute leukemia performed comparably with healthy population (33/33; 100% and 12/13; 92.3%, respectively). We have seen better results if the time interval between anti-CD20 therapy and additional vaccine dose was longer than 6 months (5/8 patients achieved seroconversion on 4th booster dose after previous failure). Also, 36 patients received a 4th dose of vaccine as a booster with measurable increase in protective antibodies in 50% (18/36).

CONCLUSIONS

Additional doses show promise for a well-timed revaccination even in poor responders. To our knowledge, no study comparable to our work in terms of follow-up length, vaccine consistency or variety of hematological malignancies and/or treatment has been reported yet. Our findings shed more light on long-term antibody response to mRNA vaccines against SARS-CoV-2 in patients with hematological cancer and bring important data for the evaluation of possible vaccine failure and scheduling of subsequent doses.

Cancer/Testis Antigens as Targets for RNA-Based Anticancer Therapy

In the last few decades, RNA-based drugs have emerged as a promising candidate in the treatment of various diseases. The introduction of messenger RNA (mRNA) as a vaccine or therapeutic agent enables the production of almost any functional protein/peptide. The key to applying RNA therapy in clinical trials is developing safe and effective delivery systems. Exosomes and lipid nanoparticles (LNPs) have been exploited as promising vehicles for drug delivery. This review discusses the feasibility of exosomes and LNPs as vehicles for mRNA delivery. Cancer/testis antigens (CTAs) show restricted expression in normal tissues and widespread expression in cancer tissues. Many of these CTAs show expression in the sera of patients with cancers. These characteristics of CTAs make them excellent targets for cancer immunotherapy. This review summarizes the roles of CTAs in various life processes and current studies on mRNAs encoding CTAs. Clinical studies present the beneficial effects of mRNAs encoding CTAs in patients with cancers. This review highlight clinical studies employing mRNA-LNPs encoding CTAs.