Preventing SARS-CoV-2 infection is of utmost importance in allogeneic hematopoietic cell transplantation patients (allo-HCT), given their heightened susceptibility to adverse outcomes associated with SARS-CoV-2 infection. However, limited data are available regarding the immune response to COVID-19 vaccines in these subjects, particularly concerning the generation and persistence of spike-specific memory response. Here, we analyzed the spike-specific memory B cells in a cohort of allo-HCT recipients vaccinated with multiple doses of the mRNA-1273 vaccine and monitored the spike-specific antibody response from baseline up to one month after the fourth dose. After the primary vaccine series, the frequency of spike-specific B cells, detected within the pool of Ig-switched CD19+ cells, significantly increased. The booster dose further induced a significant expansion, reaching up to 0.28% of spike-specific B cells. The kinetics of this expansion were slower in the allo-HCT recipients compared to healthy controls. Spike-specific IgG and ACE2/RBD binding inhibition activity were observed in 80% of the allo-HCT recipients after the first two doses, with a significant increase after the third and fourth booster doses, including in the subjects who did not respond to the primary vaccine series. Additionally, 87% of the allo-HCT recipients exhibited positive cross-inhibition activity against the BA.1 variant. Our findings provide evidence that allo-HCT recipients need repeated doses of the mRNA-1273 vaccine to induceSARS-CoV-2 specific immune response similar to that observed in healthy individuals. This is particularly crucial for vulnerable individuals who may exhibit a limited response to the primary series of SARS-CoV-2 vaccination.

COVID-19 caused by SARS-CoV-2 is a great threat to public health. We present the safety and immunogenicity data from a phase I trial in China of an mRNA vaccine (LVRNA009).
In the single-centre, double-blind, placebo-controlled and dose-escalation study, 72 healthy unvaccinated adults aged 18-59 years were randomized (3:1) to receive LVRNA009 with one of three vaccine dosage (25, 50 and 100 μg) or placebo, to evaluate for the safety, tolerability and immunogenicity of LVRNA009.
All these participants received two injections 28 days apart. No adverse events higher than grade 2 were reported during the study. A total of 30 participants (42 %) reported solicited adverse reactions during the first 14 days after vaccinations. Of the events reported, fever (n = 11, 15 %) was the most common systemic adverse reaction, and pain at the injection site (n = 17, 24 %) was the most frequent solicited local adverse reaction. Anti-S-protein IgG and neutralising antibodies were observed to have been induced 14 days after the first dose, significantly increased 7 days after the second dose, and remained at a high level 28 days after the second dose. Specific T-cell responses peaked 7 days and persisted 28 days after second vaccination.
LVRNA009 has demonstrated promising results in safety and tolerability at all three dose levels among Chinese adults. LVRNA009 at three dose levels could rapidly induce strong humoral and cellular immune responses, including binding and neutralising antibody production and IFN- γ secretion, which showed good immunogenicity.
Clinicaltrials.gov NCT05364047; Chictr.org.cn ChiCTR2100049349.

Since the beginning of the mass immunization of patients with multiple sclerosis (MS), many data on the efficacy and safety of COVID-19 vaccines have been produced. Considering that MS is an autoimmune disease and that some disease-modifying therapies (DMTs) could decrease the antibody response against COVID-19 vaccines, we carried out this retrospective study with the aim to evaluate the safety of these vaccines in terms of AEFI occurrence and the antibody response after MS patients had received the third dose. Two hundred and ten patients (64.8% female; mean age: 46 years) received the third dose of the mRNA-based COVID-19 vaccine and were included in the study. Third doses were administered from October 2021 to January 2022. The majority of patients (n = 193) were diagnosed with RRMS and EDSS values were ≤3.0 in 72.4% of them. DMTs most commonly used by included patients were interferon Beta 1-a, dimethyl fumarate, natalizumab and fingolimod. Overall, 160 patients (68.8% female) experienced 294 AEFIs, of which about 90% were classified as short-term, while 9.2% were classified as long-term. The most commonly reported following the booster dose were pain at the injection site, flu-like symptoms, headache, fever and fatigue. Regarding the immune response, consistently with literature data, we found that patients receiving ocrelizumab and fingolimod had lower IgG titer than patients receiving other DMTs.

In the current COVID-19 pandemic, patients diagnosed with multiple sclerosis (MS) are considered to be one of the highest priority categories, being recognized as extremely vulnerable people. For this reason, mRNA-based COVID-19 vaccines are strongly recommended for these patients. Despite encouraging results on the efficacy and safety profile of mRNA-based COVID-19 vaccines, to date, in frail populations, including patients diagnosed with MS, this information is rather limited. We carried out a retrospective observational study with the aim to evaluate the safety profile of mRNA-based COVID-19 vaccines by retrieving real-life data of MS patients who were treated and vaccinated at the Multiple Sclerosis Center of the Hospital A.O.R.N. A. Cardarelli. Three-hundred and ten medical records of MS patients who received the first dose of the mRNA-based COVID-19 vaccine were retrieved (63% female; mean age: 45.9 years). Of these patients, 288 also received the second dose. All patients received the Pfizer-BioNTech vaccine. Relapsing-Remitting Multiple Sclerosis (RRSM) was the most common form of MS. The Expanded Disability Status Scale (EDSS) values were <3.0 in 70% of patients. The majority of patients received a Disease Modifying Therapy (DMT) during the study period, mainly interferon beta 1-a, dimethyl fumarate, and natalizumab and fingolimod. Overall, 913 AEFIs were identified, of which 539 were after the first dose of the vaccine and 374 after the second dose. The majority of these AEFIs were classified as short-term since they occurred within the first 72 h. The most common identified adverse events were pain at injection site, flu-like symptoms, and headache. Fever was reported more frequently after the second dose than after the first dose. SARS-CoV-2 infection occurred in 3 patients after the first dose. Using historical data of previous years (2017−2020), the relapses’ rate during 2021 was found to be lower. Lastly, the results of the multivariable analysis that assessed factors associated with the occurrence of AEFIs revealed a statistical significance for age, sex, and therapy with ocrelizumab (p < 0.05). In conclusion, our results indicated that Pfizer-BioNTech vaccine was safe for MS patients, being associated with AEFIs already detected in the general population. Larger observational studies with longer follow-up and epidemiological studies are strongly needed.

Large-scale coronavirus disease 2019 (COVID-19) vaccination programs have been rolled out worldwide. Vaccines that are widely used globally include mRNA vaccines, adenoviral vector vaccines, and inactivated whole-virus vaccines. COVID-19 vaccines can lead to varying side effects. Among the most common of these adverse effects are pain at the injection site, fatigue, and headaches. Some side effects, however, are not very well documented, and these include joint-related adverse effects. In this review, we assess the epidemiology and clinical features of post-COVID-19 vaccination joint-related adverse effects based on the analysis of 16 patient case reports. Based on our analysis, we found that females formed the majority of the cases, accounting for 62.5% of patients, while 37.5% of the cases were males. The mean age of presentation among the patients was 54.8 years, with a standard deviation (SD) of 17.49 years. In 37.5% of the cases, patients received the Sinovac vaccine. The proportion of patients who received other vaccines was as follows: the Pfizer vaccine: 31.25%; Sputnik V: 12.5%; Moderna, AstraZeneca, and Covaxin: 6.25% each. The characteristics of joint-related adverse effects following COVID-19 vaccination were analyzed in this study. We identified several key findings related to factors such as age, gender, type of vaccine, clinical features, and diagnosis modality. Our analysis showed that more cases were reported among individuals who received the Sinovac vaccine, as compared to the others. Further research is required to examine the underlying cause of this association.