Tuberculosis vaccines in the era of Covid-19 - what is taking us so long?

The Mycobacterium bovis BCG vaccine was first used in 1921, but has not controlled the global spread of tuberculosis (TB). There are still no new licensed tuberculosis vaccines, although there much active research and a vaccine development pipeline, with vaccines designed to prevent infection, prevent disease, or accelerate TB treatment. These vaccines are of different types, and designed to replace BCG, or to boost immunity following BCG vaccination. This viewpoint discusses why, when it has been possible to develop new vaccines for SARS-CoV-2 so quickly, it is taking so long to develop new tuberculosis vaccines.

Acceptance of COVID-19 vaccine among persons experiencing homelessness in the City of Rome, Italy.

OBJECTIVE: Vulnerable populations are being more severely impacted by the ongoing pandemic, and the recent release of vaccines for Coronavirus Disease 19 (COVID-19) may offer them protection. The aim of this study was to investigate the willingness of homeless persons to be vaccinated against COVID-19; secondary aims were to analyze the immunization coverage for other conditions. PATIENTS AND METHODS: The acceptance of COVID-19 vaccine and immunization coverage for other conditions were investigated through a form in 112 persons experiencing homelessness referring to the primary care medical services of the Eleemosynaria Apostolica, Holy See. RESULTS: Most subjects, with a male preponderance, were willing to be vaccinated against COVID-19 (64.3%), 3.6% were unsure and 32.1% preferred not to be vaccinated. When answering questions on the immunization coverage for tuberculosis and hepatitis A and B, most subjects reported not to be vaccinated (48.2%, 56.2% and 55.3%, respectively) or did not know (33%, 28.6% and 27.7%). CONCLUSIONS: A significant portion of our sample declared to be willing to be vaccinated against COVID-19. It would be auspicious that the recent statements from several countries on the importance to extend COVID-19 vaccination to fragile populations be followed by the distribution of the vaccine to these populations.

Perspective of Covid-19 pandemic in South Asian countries.

COVID-19 is rapidly spreading throughout the world since December 2019. It has hit South Asian countries with faded impact, which can be attributed to (a) availability of kits, (b) number of people tested for COVID-19, (c) immunity, (d) environmental conditions and (e) vaccination.

Bacille Calmette Guérin (BCG) and new TB vaccines: Specific, cross-mycobacterial and off-target effects.

The Bacille Calmette Guérin (BCG) vaccine was developed over a century ago and has become one of the most used vaccines without undergoing a modern vaccine development life cycle. Despite this, the vaccine has protected many millions from severe and disseminated forms of tuberculosis (TB). In addition, BCG has cross-mycobacterial effects against non-tuberculous mycobacteria and off-target (also called non-specific or heterologous) effects against other infections and diseases. More recently, BCG's effects on innate immunity suggest it might improve the immune response against viral respiratory infections including SARS-CoV-2. New TB vaccines, developed over the last 30 years, show promise, particularly in prevention of progression to disease from TB infection in young adults. The role of BCG in the context of new TB vaccines remains uncertain as most participants included in trials have been previously BCG immunised. BCG replacement vaccines are in efficacy trials and these may also have off-target effects.