|LETTER TO THE EDITOR
|Ahead of print publication
BCG and COVID-19 immunization coverage and clinical nature of disease: Analysis of situation in Indochina
Rujittika Mungmunpuntipantip1, Viroj Wiwanitkit2
1 Private Academic Consultant, Bangkok, Thailand
2 Department of Community Medicine, Dr. DY Patil University, Pune, Maharashtra, India
|Date of Submission||20-Feb-2021|
|Date of Decision||28-Apr-2022|
|Date of Acceptance||08-May-2022|
Private Academic Consultant, Bangkok
Source of Support: None, Conflict of Interest: None
|How to cite this URL:|
Mungmunpuntipantip R, Wiwanitkit V. BCG and COVID-19 immunization coverage and clinical nature of disease: Analysis of situation in Indochina. Med J DY Patil Vidyapeeth [Epub ahead of print] [cited 2022 Dec 7]. Available from: https://www.mjdrdypv.org/preprintarticle.asp?id=350681
Dear Editor, coronavirus disease (COVID-19) pandemic is an urgent global public health emergency. Specific treatment for this infection is still not available. There are many attempts to use available classic therapies for the treatment and prevention of disease. Of several options, Bacillus Calmette–Guérin (BCG), a vaccine for tuberculosis is mentioned for its possible effectiveness in COVID-19 management. Nevertheless, many medical scientists gave expert ideas against the usefulness of BCG.,, In fact, BCG is a classical primary immunoprevention that is used worldwide. An important query is on the interrelationship between BCG coverage and the clinical nature of COVID-19. Here, the author assesses such interrelationship based on an area with an extremely high prevalence of tuberculosis, Indochina (five countries in Southeast Asia; Thailand, Vietnam, Laos, Cambodia, and Myanmar).
The present study is a data research. The primary data on BCG coverage rate, according to World Health Organization - United Nations Children's Fund estimates of BCG coverage (data available on https://apps.who.int/immunization_monitoring/globalsummary/timeseries/tswucoveragebcg.html) and COVID-19 epidemiology (data available on https://www.worldometers.info/coronavirus/#countries; data on 15 May 2020) are used for further analysis. The correlation between the BCG coverage rate and the infection rate/death rate is done.
On the basis of this study, from correlation analysis, there is no statistically significant association between the BCG coverage rate and infection rate or death rate of COVID-19 (P > 0.05) [Table 1]. The correlation coefficient value is equal to 0.502 for an association between the BCG coverage rate and the infection rate and from 0.579 to 0.502 for an association between the BCG coverage rate equal and the death rate, respectively. A high BCG coverage rate is not related to the low infection rate or death rate of COVID-19. COVID-19 infection and fatality rates are low in many areas with poor BCG immunization rates. This finding can support the previous ideas that BCG might not play a role in the prevention and treatment of COVID-19.
|Table 1: BCG coverage rate and infection rate/death rate of COVID-19 in Indochina countries|
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Some limitations of the present work should be discussed. Basically, BCG vaccination does not provide protection to tuberculosis (TB) infection; however, it offers protection from a severe form of TB such as TB of the central nervous system. Interestingly, BCG is proposed for the advantage of BCG. Thus, deriving a correlation with COVID-19 infectivity might be unjust. Therefore, the topic is an interesting issue for discussion. This short study for assessing the relationship and the conclusion is against the usefulness of BCG. However, linking mortality rate with BCG vaccination coverage rate would have been more informative, if it had been compared to nations that did not have BCG vaccination coverage. This research focuses on Indochina. There is no country that is not covered by BCG vaccinations. Suggestion for correlation countries without BCG vaccination coverage, if exists, is recommended. In addition, the possible clinical association with disease recovery or death might also be affected by other factors such as health care infrastructures. There may also be an effect of acquired immunity in cases of previously undiagnosed silent COVID infection. Nevertheless, this research is carried out during the early stage of the COVID-19 outbreak, and there should be no interference for occulted immunity in people with previous asymptomatic COVID.
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Conflicts of interest
There are no conflicts of interest.
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