Efficacy and Safety of BCG Revaccination With M. bovis BCG Moscow to Prevent COVID-19 Infection in Health Care Workers: A Randomized Phase II Clinical Trial

The Bacillus Calmette-Guérin (BCG) vaccine, which is widely used to protect children against tuberculosis, can also improve immune response against viral infections. This unicentric, randomized-controlled clinical trial assessed the efficacy and safety of revaccination with BCG Moscow in reducing the positivity and symptoms of COVID-19 in health care workers (HCWs) during the COVID-19 pandemic. HCWs who had negative COVID-19 IgM and IgG and who dedicated at least eight hours per week in facilities that attended to individuals suspected of having COVID-19 were included in the study and were followed for 7, 15, 30, 60, and 180 days by telemedicine. The HCWs were randomly allocated to a revaccinated with BCG group, which received the BCG vaccine, or an unvaccinated group. Revaccination with BCG Moscow was found to be safe, and its efficacy ranged from 30.0% (95.0%CI -78.0 to 72.0%) to 31.0% (95.0%CI -74.0 to 74.0%). Mycobacterium bovis BCG Moscow did not induce NK cell activation at 15–20 days post-revaccination. As hypothesized, revaccination with BCG Moscow was associated with a lower incidence of COVID-19 positivity, though the results did not reach statistical significance. Further studies should be carried out to assess whether revaccination with BCG is able to protect HCWs against COVID-19. The protocol of this clinical trial was registered on August 5th, 2020, at REBEC (Registro Brasileiro de Ensaios Clínicos, RBR-4kjqtg - ensaiosclinicos.gov.br/rg/RBR-4kjqtg/1) and the WHO (# U1111-1256-3892). The clinical trial protocol was approved by the Comissão Nacional de ética de pesquisa- CONEP (CAAE 31783720.0.0000.5078).

Tuberculosis, BCG Vaccination and COVID-19: Are They Connected?

Evidence from multiple scientific studies suggests that the Bacillus Calmette-Guérin (BCG) vaccine, widely used worldwide as a preventive measure against tuberculosis, also offers cross-protection against other pathogens. This review aimed to gather data from research that studied the mechanisms involved in the immunological protection induced by the BCG vaccine, which may be important in the control of viral infections, such as COVID-19. Through a literature review, we compiled information about the different BCG strains used worldwide, as well as the responses and protection elicited by them. We commented on the mechanisms of immune response to Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and we discussed the possibility of cross-protection of different BCG strains on the control of COVID-19. Due to the immunomodulatory properties of BCG, some BCG strains were able to induce an effective cellular immune response and, through epigenetic modifications, activate cells of the innate immune system, such as monocytes, macrophages and natural killer cells, which are crucial for the control of viral infections. Although several vaccines have already been developed and used in an attempt to control the COVID-19 pandemic, some BCG vaccine strains may help stimulate the basal defences against these pathogens and can be used as additional defences in this and future pandemics.

Gross anatomy of the longitudinal fascicle of Sapajus sp

Opposing genetic and cultural-social explanations for the origin of language are currently the focus of much discussion. One of the functions linked to the longitudinal fascicle is language, which links Wernicke’s area and Broca’s area in the brain, and its size should indicate the brain increase in the evolution. Sapajus is a New World primate genus with high cognition and advanced tool use similar to that of chimpanzees. A study of the gross anatomy of the longitudinal fascicle of Sapajus using Kingler’s method found it to differ from other studied primates, such as macaques and chimpanzees, mainly because its fibers join the cingulate fascicle. As in other non-human primates, the longitudinal fascicle of Sapajus does not reach the temporal lobe, which could indicate a way of separating these fascicles to increase white matter in relation to individual function. The study of anatomical structures seems very promising for understanding the basis of the origin of language. Indeed, socio-historical-cultural philosophy affirms the socio-cultural origin of speech, although considering the anatomical structures behind it working as a functional system.

BCG revaccination of health workers in Brazil to improve innate immune responses against COVID-19: A structured summary of a study protocol for a randomised controlled trial

Objectives

The BCG vaccine, widely used in Brazil in new-borns, induces adjuvant protection for several diseases, including childhood virus infections. BCG activates monocytes and innate memory NK cells which are crucial for the antiviral immune response. Therefore, strategies to prevent COVID-19 in health workers (HW) should be carried out to prevent them becoming unwell so that they can continue to work during the pandemic. The hypothesis is that BCG will improve the innate immune response and prevent symptomatic infection or COVID-19 severity.

The primary objective is to verify the effectiveness and safety of the BCG vaccine to prevent or reduce incidence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection in the city of Goiânia (Brazil) among HW previously vaccinated with BCG and also its severity and mortality during the pandemic of the disease.

Secondary objectives are to estimate the incidence of COVID-19 among these professionals and the innate immune response elicited to BCG.

Trial design

This a phase II trial for repositioning BCG as a preventive strategy against COVID-19.

The trial is an open-label, parallel-group randomised clinical trial, comparing HW vaccinated with BCG and HW not vaccinated.

Participants

The trial will recruit 800 HW of Goiânia - Goiás, Brazil to reach a total of 400 HW included after comorbidities questioning and laboratorial evaluation.

Eligibility criteria: Any HW presenting BCG vaccination scar with direct contact with suspected COVID-19 patients for at least 8 hours per week, whether in hospital beds, ICU, or in transportation or admission (nurses, doctors, physiotherapists, nutritionists, receptionists, etc.) who have negative IgM and IgG COVID-19 test.

Participants with any of the following characteristics will be excluded:

- Have had in the last fifteen days any signs or symptoms of virus infection, including COVID-19;

- Have had fever in the last fifteen days;

- Have been vaccinated fifteen days before the inclusion;

- Have a history or confirmation of any immunosuppressive disease such as HIV, presented solid tumour in the last two years or autoimmune diseases;

- Are under preventive medication with antibiotics, steroid anti-inflammatories, or chemotherapy;

- Have less than 500 neutrophils per mL of blood;

- Have previously been diagnosed with tuberculosis;

- Are breastfeeding or pregnant;

- Are younger than 18 years old;

- Are participating as an investigator in this clinical trial.

Intervention and comparator

HW will be randomized into the BCG vaccinated group or the BCG unvaccinated control group.

The BCG vaccinated group will receive in the right arm, intradermally, a one off dose of 0.1 mL corresponding to approximately 2 x10⁵ to 8 x10⁵ CFU of live, freeze-dried, attenuated BCG Moscow 361-I, Bacillus Calmette Guerin vaccine (Serum Institute of India PVT. LTD.).

The unvaccinated control group will not be vaccinated.

The HW allocated in both groups will be followed up at specific times points until 180 days post inclusion.

The vaccinated and control groups will be compared according to COVID-19 related outcomes.

Main outcomes

The primary outcomes are the incidence coefficient of infection by SARS-CoV-2 determined by RT-PCR of naso-oropharyngeal swab specimen or rapid lateral flow IgG and IgM test, and presence of general COVID-19 symptoms, disease severity and admission to hospital during the 180 days of follow up.

The secondary outcome is the innate immune response elicited 15-20 days after vaccination.

Randomisation

The vaccine vial contains approximately 10 doses. In order to optimize the vaccine use, the randomisation was performed in blocks of 20 participants using the platform randomization.com [http://www.jerrydallal.com/random/permute.htm].

The randomization was prepared before any HW inclusion. The results were printed and inserted in sealed envelopes that were numbered with BCG-001 to BCG-400. The printed results as well the envelopes had the same numbers. At the time of the randomisation, each participant that meets the inclusion criteria will receive a consecutive participant number [BCG-001-BCG-400]. The sealed envelope with the assigned number, blinded to the researchers, will be opened in front of the participant and the arm allocation will be known.

Blinding (masking)

There is no masking for the participants or for the healthcare providers.

The study will be blinded to the laboratory researchers and to those who will be evaluating the outcomes and performing the statistical analyses. In this case, only the participant identification number will be available.

Numbers to be randomised (sample size)

Four hundred heath workers will be randomised in two groups. Two hundred participants will be vaccinated, and 200 participants will not be vaccinated.

Trial Status

The protocol approved by the Brazilian Ethical Committee is the seventh version, number CAAE: 31783720.0.0000.5078. The trial has been recruiting since September 20^th, 2020. The clinical trial protocol was registered on August 5^th, 2020. It is estimated that recruitment will finish by March 2021.

Trial registration

The protocol number was registered on August 5^th, 2020 at REBEC (Registro Brasileiro de Ensaios Clínicos). Register number: RBR-4kjqtg and WHO trial registration number UTN: U1111-1256-3892.

Full protocol

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s13063-020-04822-0.

The prefrontal areas and cerebral hemispheres of the neotropical Cebus apella and its correlations with cognitive processes

The organization of the prefrontal cortex can hold important clues to understanding its functioning. The Cebus apella present cerebral particularities and behavioral and cognitive flexibility, possessing abilities that demonstrate an overlap with those of big primates.