The impact of COVID-19 is changing with country wise and depend on universal immunization policies. COVID-19 badly affects countries that did not have universal immunization policies or having them only for the selective population of countries (highly prominent population) like Italy, USA, UK, Netherland, etc. Universal immunization of BCG can provide great protection against the COVID-19 infection because the BCG vaccine gives broad protection against respiratory infections. BCG vaccine induces expressions of the gene that are involved in the antiviral innate immune response against viral infections with long-term maintenance of BCG vaccine-induced cellular immunity. COVID-19 cases are reported very much less in the countries with universal BCG vaccination policies such as India, Afghanistan, Nepal, Bhutan, Bangladesh, Israel, Japan, etc. as compared to without BCG implemented countries such as the USA, Italy, Spain, Canada, UK, etc. BCG vaccine provides protection for 50–60 years of immunization, so the elderly population needs to be revaccinated with BCG. Several countries started clinical trials of the BCG vaccine for health care workers and elderly people. BCG can be uses as a prophylactic treatment until the availability of the COVID-19 vaccine.

COVID-19的影响随着国家的变化而变化，并取决于普遍的免疫政策。COVID-19对没有普遍免疫政策或仅针对意大利，美国，英国，荷兰等国家的特定人群（非常重要的人口）实施这些政策的国家造成严重影响。 -19感染是因为BCG疫苗对呼吸道感染具有广泛的保护作用。BCG疫苗可诱导长期参与BCG疫苗诱导的细胞免疫的抗病毒先天免疫应答基因表达。在印度，阿富汗，尼泊尔，不丹，孟加拉国，以色列，日本等具有普遍BCG疫苗接种政策的国家，报告的COVID-19病例要少得多。与未实施BCG的国家（如美国，意大利，西班牙，加拿大，英国等）相比，BCG疫苗可提供50-60年的免疫保护，因此老年人需要接种BCG。有几个国家开始了针对医护人员和老年人的卡介苗疫苗的临床试验。BCG可以用作预防性治疗，直到获得COVID-19疫苗为止。