BCG vaccination potential for COVID-19: an analytical approach

The African Kelleni's roadmap using nitazoxanide and broad-spectrum antimicrobials to abort returning to COVID-19 square one

For over 3.5 years, SARS CoV-2 is continuing to evolve threatening to return all and any improvement the world has made into square one. In this clinically oriented systematic review and perspective, the author explains how the best current medical evidence is strongly supporting the use of the low cost, widely available and very safe nitazoxanide in early management of COVID-19, debates the relevant theoretical studies that negated or doubted this benefit, and suggests an African roadmap to preempt the worst-case scenario if or when a new SARS CoV-2 (sub) variant or even a new respiratory virus causes a new global surge of morbidity and mortality. Kelleni's protocol, including nitazoxanide as an integral component, is continuing to perfectly save lives of patients infected with many viruses, including SARS CoV-2 and the author stresses that respiratory RNA viruses are best managed with early pharmacological treatment. Broad-spectrum antimicrobials as nitazoxanide and azithromycin together with other therapeutics as non-steroidal anti-inflammatory drugs and the antihistaminic loratadine should be considered first to personalize the clinical management of COVID-19 and selected other alarming viral infections.

Recombinant Bacillus Calmette-Guérin Expressing SARS-CoV-2 Chimeric Protein Protects K18-hACE2 Mice against Viral Challenge

COVID-19 has accounted for more than 6 million deaths worldwide. Bacillus Calmette-Guérin (BCG), the existing tuberculosis vaccine, is known to induce heterologous effects over other infections due to trained immunity and has been proposed to be a potential strategy against SARS-CoV-2 infection. In this report, we constructed a recombinant BCG (rBCG) expressing domains of the SARS-CoV-2 nucleocapsid and spike proteins (termed rBCG-ChD6), recognized as major candidates for vaccine development. We investigated whether rBCG-ChD6 immunization followed by a boost with the recombinant nucleocapsid and spike chimera (rChimera), together with alum, provided protection against SARS-CoV-2 infection in K18-hACE2 mice. A single dose of rBCG-ChD6 boosted with rChimera associated with alum elicited the highest anti-Chimera total IgG and IgG2c Ab titers with neutralizing activity against SARS-CoV-2 Wuhan strain when compared with control groups. Importantly, following SARS-CoV-2 challenge, this vaccination regimen induced IFN-γ and IL-6 production in spleen cells and reduced viral load in the lungs. In addition, no viable virus was detected in mice immunized with rBCG-ChD6 boosted with rChimera, which was associated with decreased lung pathology when compared with BCG WT-rChimera/alum or rChimera/alum control groups. Overall, our study demonstrates the potential of a prime-boost immunization system based on an rBCG expressing a chimeric protein derived from SARS-CoV-2 to protect mice against viral challenge.

Effectiveness of booster BCG vaccination in preventing Covid-19 infection

The evidence that BCG (bacille Calmette-Guerin) vaccine may increase the ability of the immune system to fight off pathogens other than tuberculosis has been studied in the past. This nonspecific immunity gained our interest, especially after initial reports of less cases in countries with universal BCG vaccination. In hopes of possible protective immunity, all staff of the Emirates International Hospital (United Arab Emirates) were offered a booster BCG vaccine in early March 2020. All the hospital staff were then tested for Covid-19 infection by the end of June 2020. We divided the subjects into two groups: booster vaccinated versus unvaccinated. The rate of Covid-19 infection was compared between the groups. Criteria included all staff who were offered the vaccine. Seventy-one subjects received the booster vaccination. This group had zero cases of positive COVID 19 infection. Two hundred nine subjects did not receive the vaccination, with 18 positive PCR confirmed COVID 19 cases. The infection rate in the unvaccinated group was 8.6% versus zero in the booster vaccinated group (Fisher’s exact test p-value = .004). Our findings demonstrated the potential effectiveness of the booster BCG vaccine, specifically the booster in preventing Covid-19 infections in an elevated-risk healthcare population.