BCG vaccine: Worrying proposal for COVID-19

Abstract

Bacille Calmette-Guérin (BCG) vaccine is proven to be effective in protecting against severe tuberculosis. It has been suggested to be able to exert a non-specific beneficial effect as protection against other infectious diseases. The duration of protection against tuberculosis is estimated to be from 10 to 15 years, but the duration of the protection against other infections is not known, maybe up to 20 years, maybe much shorter than that. We don’t know it for sure. BCG induced trained immunity paradigm is based on experimental models, cohort studies with low number of individuals, and some epidemiological data in which other possible interfering factors are not controlled. The titles and scopes of scientific articles should be cautiously considered as they can promote indications of getting vaccinated or revaccinated with BCG, before its effectiveness is confirmed and recommendations are published. Besides, revaccination with BCG can put at serious risk patients with primary or secondary immunodeficiency. Maybe BCG vaccine is effective in preventing COVID-19 deaths or reducing its severity, but may the effect of this vaccine be relevant even with poor health politics and assistance? It is very difficult to compare the epidemiologic data about COVID-19 in different countries. There are countless factors, mainly social and related to the healthcare system, which can be more decisive than the hypothesis of trained immunity induced by BCG. Until now, we can say that BCG’s protective role is, at least, insufficient, given many other factors that corroborate SARS-CoV-2 infection and/or its severity.

COVID-19 Severity and Neonatal BCG Vaccination among Young Population in Taiwan

“…In contrast, the inverse relation between COVID-19 disease burden and BCG vaccination was not observed by others [15,16]. However, these results are based on epidemiological data and have inherent biases [17,18]. Of note, all these studies analyzed aggregated data at the population level without directly comparing individuals that did receive BCG vaccinations to those that did not receive BCG vaccinations.…”

BCG Vaccination: A potential tool against COVID-19 and COVID-19-like Black Swan incidents

“…Potential confounding factors must be considered in epidemiological studies to avoid disturbing the results, including differences in health systems, levels of economic development, income, education, demographics, rural and urban environments, timing of COVID-19 outbreaks, number and criteria of diagnostic tests, national control strategies and possible arbitrary selection bias [88] , [110] , [114] . Besides, there are some inherent uncertainty issues or biases.…”

“…For example, these studies were based on population-level data, with little investigation and analysis at the individual level (for example, individuals who received BCG vaccination and those who did not), resulting in much information being ignored. Another example is that if studies are carried out during a rapidly progressing pandemic, the number of cases and deaths may be underestimated in many low- and middle-income countries vaccinated with BCG, as these countries have fewer COVID-19 tests and more underreported / misclassified deaths [84] , [114] , [115] . In addition, although BCG vaccination coverage in South America and South Africa is high, the number of COVID-19 deaths in both of them is still rising rapidly with the global spread of the epidemic.…”

Vaksin dan Sentimen Publik: Sebuah Analisis

“…Salah satu keresahan yang diperdebatkan adalah konspirasi seputar vaksin yang diberikan. Keyakinan untuk menerima vaksin termanipulatif dengan isu-isu yang keliru misalnya cairan vaksin mengandung unsur babi, oknum dokter yang meragukan peruntukkan vaksin sebagai upaya mematikan bukan menyembuhkan, efek vaksin yang dapat menyebabkan kelumpuhan, konspirasi elit global dan berbagai argumentasi lainnya (Sarinho et al, 2021).…”

“…Salah satu keresahan yang diperdebatkan adalah konspirasi seputar vaksin yang diberikan. Keyakinan untuk menerima vaksin termanipulatif dengan isu-isu yang keliru misalnya cairan vaksin mengandung unsur babi, oknum dokter yang meragukan peruntukkan vaksin sebagai upaya mematikan bukan menyembuhkan, efek vaksin yang dapat menyebabkan kelumpuhan, konspirasi elit global dan berbagai argumentasi lainnya(Sarinho et al, 2021).Perbedaan tanggapan dalam perdebatan di twitter juga menunjukkan argumentasi beberapa pihak yang menilai bahwa program vaksinasi adalah program yang memuakkan dengan jumlah persentasi disgust sebesar 16,38%. Kemuakan tersebut karena merasa bahwa upaya pemerintah dalam mensosialisasikan perihal vaksinasi cendrung kearah memaksakan kehendak.…”