[Disseminated infection caused by the bacillus Calmette-Guérin vaccine and SARS-CoV-2 coinfection in a patient with IL-12 receptor ß1 subunit deficiency]. / Infección diseminada por vacuna con bacilo de Calmette-Guérin y coinfección por SARS-CoV-2 en paciente con deficiencia de la subunidad ß1 del receptor de IL-12.

BACKGROUND: Inborn errors of immunity manifest with a greater susceptibility to infections, autoimmunity, autoinflammatory diseases, allergies, or malignancies. One of these is the mendelian susceptibility to mycobacterial disease. The most frequent etiology is the complete autosomal recessive deficiency of the ß1 subunit of the interleukin 12 receptor. CASE REPORT: A female patient who, by the age of six months, started with a nodular lesion in the right shoulder and ipsilateral axillary adenitis after the bacillus Calmette-Guérin vaccine was applied. Later, she developed a cutaneous fistula in the anterior thorax, the inframammary region, and chronic recidivant suppurative lymphadenitis. A disseminated infection caused by Mycobacterium bovis was diagnosed, therefore, individualized pharmacological treatment was required due to failure with the primary treatment. The patient was diagnosed with deficiency in the ß1 subunit of the interleukin 12 receptor at age six. During her last hospitalization, she presented fever, cough, and tachypnea, and SARS-CoV-2 was detected by quantitative polymerase chain reaction. The patient has had a favorable evolution. CONCLUSION: In patients with disseminated infections caused by bacillus Calmette-Guérin vaccination or by environmental mycobacteria, there should be suspicion of an inborn error of immunity and the patient should be referred to a third level hospital for an early immunological assessment.

Antecedentes: Los errores innatos de la inmunidad se manifiestan con una mayor susceptibilidad a infecciones, autoinmunidad, enfermedades autoinflamatorias, alergia o malignidad. Uno de estos es la susceptibilidad mendeliana a infecciones micobacterianas. La etiología más frecuente es la deficiencia completa autosómica recesiva de la subunidad ß1 del receptor de interleucina 12. Caso clínico: Paciente que comenzó a los seis meses de edad con una lesión nodular en hombro derecho y adenitis axilar ipsolateral posterior a la vacuna con bacilo de Calmette-Guérin. Posteriormente desarrolló una fistula cutánea en tórax anterior, región inframamaria y linfadenitis supurativa crónica recidivante. Se diagnosticó infección diseminada por Mycobacterium bovis, por lo que requirió tratamiento farmacológico individualizado debido al fracaso con el tratamiento primario. La paciente fue diagnosticada con deficiencia de la subunidad ß1 del receptor de interleucina 12 a los seis años. Durante su última hospitalización presentó fiebre, tos y taquipnea, detectándose SARS-CoV-2 por reacción en cadena de la polimerasa cuantitativa. La paciente evolucionó favorablemente. Conclusión: En los pacientes con infecciones diseminadas por la vacuna con bacilo de Calmette-Guérin o micobacterias ambientales, debe sospecharse un error innato de la inmunidad y derivarlos a tercer nivel de atención para la evaluación inmunológica temprana.

BCG Vaccination of Health Care Workers Does Not Reduce SARS-CoV-2 Infections nor Infection Severity or Duration: a Randomized Placebo-Controlled Trial.

Bacillus Calmette-Guerin (BCG) vaccination has been hypothesized to reduce severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, severity, and/or duration via trained immunity induction. Health care workers (HCWs) in nine Dutch hospitals were randomized to BCG or placebo vaccination (1:1) in March and April 2020 and followed for 1 year. They reported daily symptoms, SARS-CoV-2 test results, and health care-seeking behavior via a smartphone application, and they donated blood for SARS-CoV-2 serology at two time points. A total of 1,511 HCWs were randomized and 1,309 analyzed (665 BCG and 644 placebo). Of the 298 infections detected during the trial, 74 were detected by serology only. The SARS-CoV-2 incidence rates were 0.25 and 0.26 per person-year in the BCG and placebo groups, respectively (incidence rate ratio, 0.95; 95% confidence interval, 0.76 to 1.21; P = 0.732). Only three participants required hospitalization for SARS-CoV-2. The proportions of participants with asymptomatic, mild, or moderate infections and the mean infection durations did not differ between randomization groups. In addition, unadjusted and adjusted logistic regression and Cox proportional hazards models showed no differences between BCG and placebo vaccination for any of these outcomes. The percentage of participants with seroconversion (7.8% versus 2.8%; P = 0.006) and mean SARS-CoV-2 anti-S1 antibody concentration (13.1 versus 4.3 IU/mL; P = 0.023) were higher in the BCG than placebo group at 3 months but not at 6 or 12 months postvaccination. BCG vaccination of HCWs did not reduce SARS-CoV-2 infections nor infection duration or severity (ranging from asymptomatic to moderate). In the first 3 months after vaccination, BCG vaccination may enhance SARS-CoV-2 antibody production during SARS-CoV-2 infection. IMPORTANCE While several BCG trials in adults were conducted during the 2019 coronavirus disease epidemic, our data set is the most comprehensive to date, because we included serologically confirmed infections in addition to self-reported positive SARS-CoV-2 test results. We also collected data on symptoms for every day during the 1-year follow-up period, which enabled us to characterize infections in detail. We found that BCG vaccination did not reduce SARS-CoV-2 infections nor infection duration or severity but may have enhanced SARS-CoV-2 antibody production during SARS-CoV-2 infection in the first 3 months after vaccination. These results are in agreement with other BCG trials that reported negative results (but did not use serological endpoints), except for two trials in Greece and India that reported positive results but had few endpoints and included endpoints that were not laboratory confirmed. The enhanced antibody production is in agreement with prior mechanistic studies but did not translate into protection from SARS-CoV-2 infection.

Bacillus Calmette-Guérin vaccine for prevention of COVID-19 and other respiratory tract infections in older adults with comorbidities: a randomized controlled trial.

OBJECTIVES: To test whether Bacillus Calmette-Guérin (BCG) vaccination would reduce the incidence of COVID-19 and other respiratory tract infections (RTIs) in older adults with one or more comorbidities. METHODS: Community-dwelling adults aged 60 years or older with one or more underlying comorbidities and no contraindications to BCG vaccination were randomized 1:1 to BCG or placebo vaccination and followed for 6 months. The primary endpoint was a self-reported, test-confirmed COVID-19 incidence. Secondary endpoints included COVID-19 hospital admissions and clinically relevant RTIs (i.e. RTIs including but not limited to COVID-19 requiring medical intervention). COVID-19 and clinically relevant RTI episodes were adjudicated. Incidences were compared using Fine-Gray regression, accounting for competing events. RESULTS: A total of 6112 participants with a median age of 69 years (interquartile range, 65-74) and median of 2 (interquartile range, 1-3) comorbidities were randomized to BCG (n = 3058) or placebo (n = 3054) vaccination. COVID-19 infections were reported by 129 BCG recipients compared to 115 placebo recipients [hazard ratio (HR), 1.12; 95% CI, 0.87-1.44]. COVID-19-related hospitalization occurred in 18 BCG and 21 placebo recipients (HR, 0.86; 95% CI, 0.46-1.61). During the study period, 13 BCG recipients died compared with 18 placebo recipients (HR, 0.71; 95% CI, 0.35-1.43), of which 11 deaths (35%) were COVID-19-related: six in the placebo group and five in the BCG group. Clinically relevant RTI was reported by 66 BCG and 72 placebo recipients (HR, 0.92; 95% CI, 0.66-1.28). DISCUSSION: BCG vaccination does not protect older adults with comorbidities against COVID-19, COVID-19 hospitalization, or clinically relevant RTIs.

A case series of bacillus Calmette-Guérin scar reactivation after administration of both mRNA and viral vector COVID-19 vaccines.

AIM: Reactivation of the scar resulting from intradermal injection of bacillus Calmette-Guérin (BCG) is a common specific reaction in Kawasaki's disease. It has also sporadically been associated with viral infections, multisystem inflammatory syndrome in children, influenza vaccination and mRNA COVID-19 vaccination. In this case series, characteristics of BCG scar reactivation after different COVID-19 vaccinations are presented and possible mechanisms are discussed. METHODS: Data were collected from the spontaneous reporting system of the Netherlands Pharmacovigilance Centre Lareb. Descriptives were made for the case reports in which a BCG scar reactivation was detected. RESULTS: Since the start of the COVID-19 vaccination campaign in January 2021, the Netherlands Pharmacovigilance Centre Lareb has received 22 case reports of BCG reactivation after vaccination with a COVID-19 vaccine. In 20 case reports, it concerned mRNA COVID-19 vaccines Moderna (14) and Pfizer (6). In two case reports, the viral vector COVID-19 vaccine AstraZeneca was administered. Erythema and pain were the most frequently reported symptoms and the size of the inflammation was between 1.5 and 5 cm. BCG scar reactivation occurred with a median time to onset of 2 days after the second or booster COVID-19 vaccination, whereas the median time to onset was 7 days after the first COVID-19 vaccination. None of the BCG scar reactivations were treated. CONCLUSIONS: The exact mechanism of the occurrence of BCG scar reactivation remains unknown, but involvement of heat shock protein 65 is suggested. BCG scar reactivation is a nonserious, self-limiting reaction that can occur after vaccination with both mRNA and viral vector COVID-19 vaccines.

Association between coronavirus disease morbidity and mortality rates and BCG vaccination policies in OECD countries. Authors' reply.

We appreciate the reviewer's comment to our article on the correlation between the national BCG vaccination policy and coronavirus disease 2019 among Organisation for Economic Co-operation and Development countries as of April 20, 2020. In this letter, we further updated the data up to November 1, 2020, and found that the updated results also arrive at the similar conclusion as the accepted article.

Bacillus Calmette-Guerin Vaccine and Nonspecific Immunity.

Bacillus Calmette-Guerin (BCG) vaccine is one of the most widely used vaccines in the world. It protects against many non-mycobacterial infections secondary to its nonspecific immune effects. The mechanism for these effects includes modification of innate and adaptive immunity. The alteration in innate immunity is through histone modifications and epigenetic reprogramming of monocytes to develop an inflammatory phenotype, a process called "trained immunity." The memory T cells of adaptive immunity are also responsible for resistance against secondary infections after administration of BCG vaccine, a process called "heterologous immunity." Bacillus Calmette-Guerin vaccine is known to not only boosts immune responses to many vaccines when they are co-administered but also decrease severity of these infections when used alone. The BCG vaccine by itself induces a TH1 type response, and its use as a vector has also shown promising results. This review article summarizes the studies showing effects of BCG vaccines on various viral infections, its role in enhancing vaccine responses, the mechanisms for this protective effect, and information on its effect on COVID-19.

Association between COVID-19 morbidity and mortality rates and BCG vaccination policies in OECD countries.

We compared whether the national BCG vaccination (BCGV) policy influenced coronavirus disease 2019 (COVID-19) in Organisation for Economic Co-operation and Development (OECD) countries. Those currently implementing BCGV have a reduced number of COVID-19 morbidity and mortality cases, compared to those who have never implemented a BCGV policy, suggesting the potential protective effect of BCGV against COVID-19.

Epidemiological Differences of COVID-19 Over the World.

Background Coronavirus disease 2019 (COVID-19), originally, from Wuhan, China, has now spread to most countries across the globe and devastated global healthcare systems. The impact of this disease has, however, shown baffling variations in prevalence in different regions of the world. The aim of this short review is to identify differential national COVID-19 prevalence of COVID-19, as well as to suggest these epidemiological differences.  Methods A review of studies was conducted using PubMed and Google Scholar search engines. Search tactics were centered on COVID-19 ("COVID-19" AND "coronavirus") and BCG vaccination ("BCG vaccination" OR "Bacillus Calmette-Guérin" OR "vaccine") Results It is found that national prevalence differences may be linked with BCG childhood immunization history. A statistically insignificant difference was observed in COVID-19 prevalence when comparing countries with a BGC policy and countries without it (P> 0.05). This inconclusivity suggests the influence of confounders in this study. Conclusions National differences in COVID-19 cases can be attributable to immunologic regulations, such as BCG vaccination protocols. Caution should be taken in establishing a correlation between COVID-19 prevalence and BCG vaccination, partly due to the weak quality of statistical data on COVID-19 related to poor testing rates in countries with BCG vaccination policy. Nonetheless, the analysis of the epidemiological aspects of COVID-19 will shed light on future efforts towards effective control and prevention.