BACKGROUND: Several neurological manifestations shortly after a receipt of coronavirus infectious disease 2019 (COVID-19) vaccine have been described in the recent case reports. Among those, we sought to evaluate the risk of encephalitis and meningitis after COVID-19 vaccination in the entire South Korean population.
METHODS: We conducted self-controlled case series (SCCS) analysis using the COVID-19 immunization record data from the Korea Disease Control Agency between February 2021 and March 2022, linked with the National Health Insurance Database between January 2021 and October 2022. We retrieved all medical claims of adults aged 18 years or older who received at least one dose of COVID-19 vaccines (BNT162b2, mRNA-1273, ChAdOx1-S, or Ad26.COV2.S), and included only those who had a diagnosis record for encephalitis or meningitis within the 240-day post-vaccination period. With day 0 defined as the date of vaccination, risk window was defined as days 1-28 and the control window as the remainder period excluding the risk windows within the 240-day period. We used conditional Poisson regression to estimate the incidence rate ratios (IRR) with 95% confidence intervals (CI), stratified by dose and vaccine type.
RESULTS: From 129,956,027 COVID-19 vaccine doses administered to 44,564,345 individuals, there were 251 and 398 cases of encephalitis and meningitis during the risk window, corresponding to 1.9 and 3.1 cases per 1 million doses, respectively. Overall, there was an increased risk of encephalitis in the first 28 days of COVID-19 vaccination (IRR 1.26; 95% CI 1.08-1.47), which was only significant after a receipt of ChAdOx1-S (1.49; 1.03-2.15). For meningitis, no increased risk was observed after any dose of COVID-19 vaccine (IRR 1.03; 95% CI 0.91-1.16).
CONCLUSIONS: Our findings suggest an overall increased risk of encephalitis after COVID-19 vaccination. However, the absolute risk was small and should not impede COVID-19 vaccine confidence. No significant association was found between the risk of meningitis and COVID-19 vaccination.

The rapid deployment of COVID-19 vaccines to a large proportion of the population requires a focus on safety. However, few studies have assessed the safety of COVID-19 vaccines in Africa. In Burkina Faso, this issue has not yet been addressed. The objective of this study was to contribute to the description of the characteristics of adverse events following immunization (AEFIs) related to COVID-19 vaccines in Burkina Faso. This was a cross-sectional descriptive retrospective study of spontaneous reports of COVID-19 vaccine-related AEFIs recorded in VigiBase® between June 2021 and November 2022 in Burkina Faso. Individual case safety reports (ICSRs) were extracted from VigiBase® using the Anatomical Therapeutic Chemical level 2 (ATC2) code. The proportion of ICSRs according to the reporter’s qualification, the reporting rate, the time taken to submit and record ICSRs, and the completeness score were calculated. A total of 973 ICSRs concerned COVID-19 vaccines and represented 32.6% of all 2,988 reports in VigiBase®. Overall, 82.0% of the reporters were nurses/midwives, 7.8% were physicians, 6.7% were pharmacists, and 3.4% were patients. The median time between the onset of AEFIs and the submission of the report to the Pharmacovigilance Center was 180 days (IQR: 136; 281). The median registration time was 188 days (IQR: 149; 286). The mean ICSR completeness score was 0.8 (standard deviation = 0.1). The overall AEFI reporting rate was 27.8 per 100,000 vaccine doses. The AEFI reporting rates for the ChAdOx1-nCoV-19, JNJ 78436735, Elasomeran, Tozinameran, and HB02 vaccines were 454.2, 17.4, 11.0, 10.2, and 0.4 per 100,000 vaccine doses, respectively. The majority of AEFIs were systemic in nature (90.1%). Headache (21.2%), fever (19.4%), and myalgia (11.0%) were the most frequently reported AEFIs. Eighteen cases (1.8%) of serious AEFIs (9 hospitalizations, 4 life threatening, 3 temporary disabilities, and 2 others unspecified) were reported. The majority of AEFIs reported were systemic in nature and mild. However, there have been reports of serious AEFIs. The overall AEFI reporting rate was low. There is a need to strengthen the monitoring of these vaccines to better organize strategies to optimize the adherence of the population of Burkina Faso.
Le déploiement rapide des vaccins anti COVID-19 sur une grande partie de la population nécessite de mettre l’accent sur la sécurité. Cependant, peu d’études ont évalué la sécurité des vaccins anti COVID-19 en Afrique. Au Burkina Faso, cette question n’a pas encore été abordée. La présente étude avait pour objectif de contribuer à la description des caractéristiques des manifestations post-vaccinales indésirables (MAPI) liées aux vaccins anti COVID-19 au Burkina Faso. Il s’est agi d’une étude transversale rétrospective ayant porté sur les notifications de MAPI liées aux vaccins anti COVID-19 enregistrées dans VigiBase® entre juin 2021 et novembre 2022 au Burkina Faso. Les cas individuels de rapports de sécurité (CIRS) ont été extraits de VigiBase® à l’aide du code Anatomical Therapeutic Chemical niveau 2 (ATC2). La proportion de CIRS selon la qualification du notificateur, le taux de notification, le délai de transmission et d’enregistrement des CIRS et le score d’exhaustivité ont été calculés. Au total 973 CIRS concernaient les vaccins anti COVID-19 et représentaient 32,6 % des 2 988 rapports enregistrés dans VigiBase®. La répartition des notifications en fonction de la qualification du notificateur a montré que 82,0 % étaient des infirmiers/sage femmes, 7,8 % des médecins, 6,7 % des pharmaciens et 3,4 % des patients. Le délai médian entre l’apparition des MAPI et la transmission du rapport au Centre de pharmacovigilance était de 180 jours (IQR : 136 ; 281). Le délai médian d’enregistrement était de 188 jours (IQR : 149 ; 286). Le score d’exhaustivité moyen des CIRS était de 0,8 (écart type = 0,1). Le taux global de notifications des MAPI était de 27,8 pour 100 000 doses de vaccins. Les taux de notification des MAPI pour les vaccins ChAdOx1-nCoV-19, JNJ 78436735, Elasomeran, Tozinameran et HB02 étaient de 454,2 ; 17,4 ; 11,0 ; 10,2 et 0,4 pour 100 000 doses, respectivement. La majorité des MAPI était de manifestation systémique (90,1 %). Les céphalées (21,2 %), la fièvre (19,4 %) et les myalgies (11,0 %) étaient les MAPI les plus fréquemment notifiés. Dix-huit cas (1,8 %) de MAPI graves (9 hospitalisations, 4 mises en jeu du pronostic vital, 3 incapacités temporaires et 2 autres non précisés) ont été rapportés. La majorité des cas notifiés dans le cadre de la surveillance des MAPI était de manifestation systémique et de nature bénigne. Néanmoins, des cas de MAPI graves ont été notifiés. Le taux global de notification des MAPI était faible. Il est nécessaire de renforcer la surveillance de ces vaccins pour mieux organiser les stratégies visant à optimiser l’adhésion de la population burkinabé.

BACKGROUND: Although previous studies found no-increased mortality risk after COVID-19 vaccination, residual confounding bias might have impacted the findings. Using a modified self-controlled case series (SCCS) design, we assessed the risk of non-COVID-19 mortality, all-cause mortality, and four cardiac-related death outcomes after primary series COVID-19 vaccination.
METHODS: We analyzed all deaths between December 14, 2020, and August 11, 2021, among individuals from eight Vaccine Safety Datalink sites. Demographic characteristics of deaths in recipients of COVID-19 vaccines and unvaccinated individuals were reported. We conducted SCCS analyses by vaccine type and death outcomes and reported relative incidences (RI). The observation period for death spanned from the dates of emergency use authorization to the end of the study period (August 11, 2021) without censoring the observation period upon death. We pre-specified a primary risk interval of 28-day and a secondary risk interval of 14-day after each vaccination dose. Adjusting for seasonality in mortality analyses is crucial because death rates vary over time. Deaths among unvaccinated individuals were included in SCCS analyses to account for seasonality by incorporating calendar month in the models.
RESULTS: For Pfizer-BioNTech (BNT162b2), RIs of non-COVID-19 mortality, all-cause mortality, and four cardiac-related death outcomes were below 1 and 95 % confidence intervals (CIs) excluded 1 across both doses and both risk intervals. For Moderna (mRNA-1273), RI point estimates of all outcomes were below 1, although the 95 % CIs of two RI estimates included 1: cardiac-related (RI = 0.78, 95 % CI, 0.58-1.04) and non-COVID-19 cardiac-related mortality (RI = 0.80, 95 % CI, 0.60-1.08) 14 days after the second dose in individuals without pre-existing cancer and heart disease. For Janssen (Ad26.COV2.S), RIs of four cardiac-related death outcomes ranged from 0.94 to 0.98 for the 14-day risk interval, and 0.68 to 0.72 for the 28-day risk interval and 95 % CIs included 1.
CONCLUSIONS: Using a modified SCCS design and adjusting for temporal trends, no-increased risk was found for non-COVID-19 mortality, all-cause mortality, and four cardiac-related death outcomes among recipients of the three COVID-19 vaccines used in the US.

BACKGROUND: Recently published studies have reported association of COVID-19 vaccine ChAdOx1-S (Vaxzevria) with Guillain Barré Syndrome (GBS). Less is known about the safety of other COVID-19 vaccines with respect to GBS outcome. This study investigated the association of COVID-19 vaccines with GBS in more than 15 million persons aged ≥12 years in Italy.
METHODS: Study population was all individuals aged ≥12 years who received at least one dose of COVID-19 vaccines, admitted to emergency care/hospital for GBS from 27 December 2020-30 September 2021 in Italy. Identification of GBS cases and receipt of at least one dose of mRNA-1273 (Elasomeran), BNT162b2 (Tozinameran), ChAdOx1-S (Vaxzevria) and Ad26.COV2.S (Janssen) through record linkage between regional health care and vaccination registries. Relative Incidence (RI) was estimated Self-controlled case series method adapted to event-dependent exposure using in the 42-day exposure risk period after each dose compared with other observation periods.
RESULTS: Increased risk of GBS was found after first (RI = 6.83; 95% CI 2.14-21.85) and second dose (RI = 7.41; 2.35-23.38) of mRNA-1273 and first dose of ChAdOx1-S (RI = 6.52; 2.88-14.77). Analysis by age found an increased risk among those aged≥60 years after first (RI = 8.03; 2.08-31.03) and second dose (RI = 7.71; 2.38-24.97) of mRNA-1273. The first dose of ChAdOx1-S was associated with GBS in those aged 40-59 (RI = 4.50; 1.37-14.79) and in those aged ≥ 60 years (RI = 6.84; 2.56-18.28).
CONCLUSIONS: mRNA-1273 and ChAdOx1-S vaccines were associated with an increased risk of GBS however this risk resulted in a small number of excess cases. Limitations were loss of GBS outpatient cases and imprecision of the estimates in the subgroup analysis due to a low number of events.

OBJECTIVE: Guillain-Barré syndrome (GBS) has been inconsistently associated with some coronavirus disease 2019 (COVID-19) vaccines. We aimed to quantify the risk of GBS according to the type of COVID-19 vaccine in a large population.
METHODS: Using the French National Health Data System linked to the COVID-19 vaccine database, we analyzed all individuals aged 12 years or older admitted for GBS from December 27, 2020, to May 20, 2022. We estimated the relative incidence (RI) of GBS within 1-42 days after vaccination up to the first booster dose compared with baseline periods using a self-controlled case series design. We then derived the number of cases attributable to the vaccination. Analyses were adjusted for the period and stratified by age group, sex, and for the presence of severe acute respiratory syndrome coronavirus 2 or common acute infections.
RESULTS: Of 58,530,770 people aged 12 years or older, 88.8% received at least 1 COVID-19 vaccine dose and 2,229 were hospitalized for GBS during the study period. Patients had a median age of 57 years, and 60% were male patients. The RI of GBS between 1-42 days was 2.5 (95% CI 1.8-3.6) for the first dose of ChAdOx1-S and 2.4 (95% CI 1.2-5.0) for the unique dose of Ad26.COV2.S vaccine. We estimated 6.5 attributable GBS cases per million persons having received a first dose of ChAdOx1-S and 5.7 cases per million for the Ad26.COV2.S vaccine. Except for the age group of 12-49 years after the second dose of the messenger RNA (mRNA)-1273 vaccine (RI 2.6, 95% CI 1.2-5.5), none of the RI estimates were found significantly increased for the mRNA vaccines.
CONCLUSIONS: In summary, we found increased risks of GBS after the first administration of ChAdOx1-S and Ad26.COV2.S vaccines. In this comprehensive assessment at the French population level, there was no statistically significant increase in the risk of GBS after the administration of mRNA vaccines. This is reassuring in the context of the ongoing and future use of mRNA-based booster vaccination.

We carried out a study to estimate the vaccine effectiveness (VE) of homologous vaccination schedules against COVID-19, using data from mandatory information systems from Bogota, Colombia.
A test-negative case-control study in adults from Bogota (Colombia), between March 1st of 2021 and February 25th of 2022. We assess VE among symptomatic COVID-19 cases during the Mul, Delta, and Omicron predominance periods in Bogota, with controls matched by sex, age (±5 years), and date of testing (±7 days), using a case:control ratio of 1:1. We selected homologous vaccination schedules with ChAdOx1, CoronaVac, BNT162b2, mRNA-1273, and Ad26.COV2.S. VE was reported as one minus the odds ratio in adjusted conditional logistic regressions, with their 95% confidence intervals (CI). A p-value < 0.05 was considered statistically significant.
52,913 cases were matched to controls, 16,722 for Mu, 14,094 for Delta, and 22,097 for Omicron. VE was high against COVID-19 during Mu weeks with full vaccination using the monovalent BNT162b2 (VE: 69; 95% CI, 65 to 72) vaccine and ChAdOx1 (VE: 64; 95% CI, 31 to 81) and significantly lower with CoronaVac (P < 0.001) and Ad26.COV2.S (P = 0.005). During Delta, VE against COVID-19 was higher with BNT162b2 (VE: 55; 95% CI, 51 to 58). The VE for COVID-19 cases during Omicron was higher with a booster dose of monovalent BNT162b2 (VE: 45; 95% CI, 34 to 54). The VE of primary series and booster for ChAdOx1, Ad26.COV2.S, and CoronaVac did not show protection for Omicron.
Our study provides further evidence on the protective effect of mRNA vaccines for Omicron, and warrant that the duration of protection against symptomatic infection may last for only a few months.

On 2/27/2021, FDA authorized Janssen COVID-19 Vaccine (Ad.26.COV2.S) for use in individuals 18 years of age and older. Vaccine safety was monitored using the Vaccine Adverse Event Reporting System (VAERS), a national passive surveillance system, and v-safe, a smartphone-based surveillance system.
VAERS and v-safe data from 2/27/2021 to 2/28/2022 were analyzed. Descriptive analyses included sex, age, race/ethnicity, seriousness, AEs of special interest (AESIs), and cause of death. For prespecified AESIs, reporting rates were calculated using the total number of doses of Ad26.COV2.S administered. For myopericarditis, observed-to-expected (O/E) analysis was performed based on the number verified cases, vaccine administration data, and published background rates. Proportions of v-safe participants reporting local and systemic reactions, as well as health impacts, were calculated.
During the analytic period, 17,018,042 doses of Ad26.COV2.S were administered in the United States, and VAERS received 67,995 reports of AEs after Ad26.COV2.S vaccination. Most AEs (59,750; 87.9 %) were non-serious and were similar to those observed during clinical trials. Serious AEs included COVID-19 disease, coagulopathy (including thrombosis with thrombocytopenia syndrome; TTS), myocardial infarction, Bell\'s Palsy, and Guillain-Barré syndrome (GBS). Among AESIs, reporting rates per million doses of Ad26.COV2.S administered ranged from 0.06 for multisystem inflammatory syndrome in children to 263.43 for COVID-19 disease. O/E analysis revealed elevated reporting rate ratios (RRs) for myopericarditis; among adults ages 18-64 years, the RR was 3.19 (95 % CI 2.00, 4.83) within 7 days and 1.79 (95 % CI 1.26, 2.46) within 21 days of vaccination. Of 416,384 Ad26.COV2.S recipients enrolled into v-safe, 60.9 % reported local symptoms (e.g. injection site pain) and 75.9 % reported systemic symptoms (e.g., fatigue, headache). One-third of participants (141,334; 33.9 %) reported a health impact, but only 1.4 % sought medical care.
Our review confirmed previously established safety risks for TTS and GBS and identified a potential safety concern for myocarditis.

Several cases of vaccine-associated manifestations have been published including cases of inflammatory myositis. Herein, we comprehensively review the literature on the occasion of case of a woman with inflammatory myositis following COVID-19 vaccination. A 67-year-old woman presented with left arm edema, rash, and weakness after the 2nd dose of the BTN162b2 vaccine. Raised muscle enzymes and inflammatory markers with muscle edema on MRI and myositis findings on the electromyogram established the diagnosis. She was successfully treated with methylprednisolone pulses, intravenous immunoglobulin, methotrexate, and hydroxychloroquine. Cases of inflammatory myositis, dermatomyositis, or interstitial lung disease with myositis-specific autoantibodies or myositis-associated autoantibodies within 12 weeks from SARS-CoV-2 vaccination were included. Cases with malignancy, prior or subsequent COVID-19 infection, preexisting myositis/interstitial lung disease (ILD)/dermatomyositis (DM), or other connective tissue diseases were excluded. From our search, 49 cases were identified (mean age: 56.55 + 17.17 years), 59% were women, while 12 patients received the ChAdOx1 vaccine, 27 the BNT162b2, 8 the mRNA-1273, 1 the DB15806, and 1 the Ad26.COV2.S (overall, 70% received mRNA vaccines). Muscle involvement was the most common manifestation (79.5%), followed by skin involvement (53%) and ILD (34.6%), which were more common in the m-RNA vaccinees. Muscle biopsy, MRI findings, and autoantibody profile varied significantly, while successful immunosuppressive treatment was applied in most cases. Inflammatory myositis after COVID-19 vaccination has been well documented worldwide. Current evidence in support of a pathogenic link is challenging due to significant variation in clinical manifestations, radiological, histopathological, and immunological features.

The occurrence of chronic inflammatory demyelinating polyneuropathy (CIDP) related to coronavirus disease 2019 (COVID-19) has rarely been reported. We describe two patients who were diagnosed with CIDP after COVID-19 vaccination. A 72-year-old man presented with a progressive tingling sensation and weakness below both knees for two weeks. He had been vaccinated against COVID-19 (mRNA-1273 vaccine) a month before the appearance of symptoms. Demyelinating polyneuropathy was observed in the nerve conduction studies (NCS). Intravenous immunoglobulin (IVIg) was administered under the diagnosis of Guillain-Barré syndrome (GBS), and his symptoms were improved. However, his symptoms relapsed at 10 weeks from the onset. Oral prednisolone, azathioprine, and IVIg were administered as treatment. The second case was a 50-year-old man who complained of a bilateral leg tingling sensation and gait disturbance lasting four weeks. He had received the Ad26.COV2.S vaccine against COVID-19 five weeks prior. Demyelinating polyneuropathy was observed in the NCS. He was treated with oral prednisolone, azathioprine, and IVIg for CIDP because his symptoms had lasted for more than 12 weeks from the onset. A causal relationship has not been established between COVID-19 vaccination and CIDP; however, CIDP may follow COVID-19 vaccination. As CIDP treatment is different from that for GBS, clinicians should closely monitor patients diagnosed with GBS associated with COVID-19 whether they deteriorate after initial treatment.

Vaccines against SARS-CoV-2 are the most effective measure against the COVID-19 pandemic. The safety profile of mRNA vaccines in patients with rare diseases has not been assessed systematically in the clinical trials, as these patients were typically excluded. This report describes the occurrence of agranulocytosis within days following the first dose of an mRNA-1273 vaccination against COVID-19 in a previously healthy older adult. The patient was diagnosed with a suspected STAT3 wild-type T-cell large granular lymphocytic leukaemia (T-LGL). Neutropenia was successfully treated with IVIG, glucocorticoids, and G-CSF. In vitro experiments aimed at elucidating the pathways potentially causing the mRNA vaccine-associated neutropenia indicated that the mRNA, but not the adenoviral Ad26.COV2.S vector vaccine, triggered strong IL-6/STAT3 activation in vitro, resulting in excessive T-cell activation and neutrophil degranulation in the patient but not in controls. mRNA-1273 activated TLR-3 suggesting TLR mediated IL-6/STAT3 pathway activation. To complete the primary series of COVID-19 immunization, we used a single dose of Ad26.COV2.S vector vaccine without reoccurrence of neutropenia. The T-LGL clone remained stable during the follow-up of more than 12 months without ongoing therapy. Our data suggest that switching the immunization platform may be a reasonable approach in subjects with rare associated hematologic side effects due to excess STAT3-mediated stimulation following mRNA vaccination. Using in vitro testing before re-administration of a (COVID) vaccine also has relevance for other rare immune events after (mRNA) vaccination.