Is BCG a ray of hope for Covid-19 among uncertainty?

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Till date, human being used to be the eyewitness of so many outbreaks including plague, flu, cholera and HIV/AIDS. Today, we are again battling with something which is imperceptible; i.e global COVID-19 pandemic. SARS Cov-2 (corona virus-2) is microbial organism which slowly becomes the reason of the falling economy at international level. After world war IInd, this is the biggest challenge which mankind ever has dealt with. The symptoms of the virus including fever, dry cough, tiredness, aches and pains, nasal congestion, sore throat or diarrhea. However, there are cases also reported where the individual is infected but doesn’t show any symptoms and thererfore, it is termed as asymptomatic infection.

There is a report which says that 80% cases does not show any symptoms in covid-19. All the way back to the origin of corona virus in Wuhan, China late in 2019, this virus has spread like fire to almost every country. Right now, there is no vaccine found against this deadly virus and we must also be aware by the fact that this virus is transmitted from human to human. That’s why government and Non-governmental organizations are endorsing for the preventive strategies like self quarantine or self isolation to break the chain of this virus. Still, the number of positive case is increasing on regular basis. As of 12th May 2020, the positive cases have risen to 4,271,906 and the death rate has risen to287,613 throughout the world. In spite of all this, we can get some relief by knowing the number of recovered people from corona virus and i.e. 1,535,097. There is a race between the pharma giants throughout the world to find a solution to eliminate the virus. Researchers have come up with different strategies to stop this virus and ongoing research giving us a ray of hope to overcome the crisis. Now, we have a question that ‘Do we forget our conventional vaccines which were once used as a boon to the mankind? Yes, we are talking about BCG.

Discovery of BCG Vaccine

This vaccine protects against the disease of tuberculosis caused by Mycobacterium tuberculosis (MTB) and leprosy. This vaccine is made from the weakened strain of Mycobacterium bovis, a bacterium which is nearly related to MTB. This vaccine was developed by two French biologists named Albert Calmette and Camille Guérin over a period of 13 years between1908 to 1921It has been found in a study that BCG vaccination when given to infants, it is linked with a Th1-biased immune response, antibody reaction to unrelated antigen increased, reduced atopy (genetic tendency to develop allergic diseases) and the mortality of childhood is also reduced. A review conducted by WHO in 2014,states that the potential nonspecific effects of BCG vaccine and the concerned review concludes that BCG was associated with nearly reducing mortality rate to half.

Do BCG have the capacity to overcome the challenge of Covid-19

There is epidemiological evidence that BCG causes the depletion of mortality rate by approximately 38-45%. It is actually developed to combat MTB infection but the benefit of BCG is not limited to tuberculosis only. In the beginning, this vaccine is administered to neonates shortly after births who are at high risk of tuberculosis. By seeing the reducing rate of sepsis and respiratory tract infections in neonates, it was decided that this vaccine should also be given to the elderly individuals who are in the age group between 60-75.if the concerned individual is experiencing the respiratory infections. After the vaccine is given, the results were not shocking at all as this vaccine proved effective in senior citizens as well. BCG has many benefits including to boosts host immunity against bladder cancer. In 1990, it has been approved for use in bladder cancer.

According to one of the reports of New York Institute of Technology (NYIT), the countries without having universal policies of BCG vaccination specifically United States, Italy and Netherlands have been affected more critically compared to countries with universal and well established BCG Policy. Till 12 May 2020, US have reported almost 1,385,834 active cases with 81,795 deaths. Italy has 219,814 active cases and over 30,7392 fatalities.

The above screenshot shows the countries and the confirmed covid-19 patients there. Except China, remaining are those countries which did not follow universal policy of BCG vaccination. The developed countries showing the higher number of corona virus cases. The countries like US and Italy endorsed BCG vaccines but only for those individuals who might be at risk of developing tuberculosis while other than US and Italy, Germany, Spain, France and the U.K. have the universal policy of BCG vaccination but they ended this policy for more than a decade ago. Now, coming to the China where the origin of this pandemic begins has a policy of BCG vaccination although it wasn’t cohered well enough before 1976. The countries which managed to control the disease including Japan and South Korea have universal policy of BCG vaccination.

Mihai Netea, an infectious-disease expert at Radboud University Medical Center in the Netherlands is the first to conduct the clinical trial of BCG vaccine’s effectiveness against coronavirus. There are also clinical trials of BCG vaccine taking place in Australia, Denmark, Germany, U.K. and U.S. Researchers are still working to get enough understanding about BCG vaccine. One of the decade long ago report of Netea’s shows that BCG vaccine sensitizes the immune system in a manner that, each time when any pathogen that relies on the same attack tactics as the tuberculosis bacteria attacks, it is ready to reply in a better way than the immune system of those who haven’t received the vaccine.

By seeing the risen number of COVID-19, it feels like that the death itself in the form of corona virus is playing the game of chess with our health system and we can’t afford check and mate by corona virus. So, to give the COVID-19 check and mate, our health system are doing trials of vaccines and hopefully mankind will win this war against the virus.

 

Vaccination under trial for Covid-19

In this outbreak of corona virus that causes COVID-19 pandemic, pharmaceutical companies and researchers are working as fast as possible to develop and test a vaccine. However, there is a prediction among scientists or researchers that it will take at least 12 to 18 months before it could commercially available. As of March 20, there are 70 candidate vaccines in development. We are listing some of the vaccines which are now gone for clinical trials:-

1. AD5-NCOV:- It was the first vaccine for COVID-19 to enter on human trials. This vaccine is made by the Chinese biotech firm CanSino Biologics and is now in phase II clinical trials and it claims to be the top contender by WHO among the vaccines launched for trials. The vaccine uses adenovirus which is known for its harmless action. This utilizes the adenovirus for delivering the DNA of the spike proteins present on the surface of the novel coronavirus. Spike proteins activate the immune system and produce pathogen-fighting antibodies which targets novel COVID-19 infection in the future. The vaccine Ad5-nCoV is currently in phase IInd which are expected to last six months. So, it is expected to come early next year.

2. CHADOX1:- The vaccine is developed by British scientists in Oxford University. In terms of the technique used to boost immunity, this vaccine is similar to Ad5-nCoV. Resultantly, this vaccine activates the immune system to build cells that disable the spike proteins. It would protect patients against COVID-19. This vaccine is currently in combined Phase I/II clinical trials which focus to examine the vaccine's efficiency and its well-being.

3. INO-4800:- The vaccine is developed by Inovio Pharmaceuticals which is a US biotech firm. The concerned vaccine is now in phase I clinical trial. It is a candidate DNA vaccine which is matched with novel Covid-19. This vaccine delivers optimized DNA into cells, where it is translated into proteins that triggers an individual's immune system to produce a robust targeted T cell and antibody response.

4. PICOVACC:- This vaccine is developed by Beijing-based Sinovac Biotech has been proven effective in monkeys. The idea of this vaccine is to inject the debilitate virus into an animal’s body, compelling its immune system to generate antibodies. The researchers of Sinovac Biotech injected the vaccine into rhesus macaques. Three weeks later, the monkeys are unveiled to the novel coronavirus. After one week, they got checked for the virus. Those monkeys who took the largest doses of the vaccine didn’t have virus in their lungs whereas few monkeys that didn’t get the vaccine were trapped by virus and develop acute pneumonia. The vaccine is undergoing in combined phase I/II human trials and expected to come in next year.

     5. MRNA-1273:- This vaccine is developed by National Institute of Health (NIH). The     vaccine is made by genetic policy called Messenger RNA (mRNA). This experimental vaccine targets the body cell’s ability to expel a virus protein and it is expected that will elicit the immune system against COVID-19. Currently, it is in Phase I clinical trial and is hoped to come in phase II trial within a couple of months.

Apart from all the vaccinations are developing or under developed for COVID-19. We highly recommend universal policy of BCG vaccination to uplift the immune system whether the person is at risk to develop tuberculosis or is totally fine from any disease. Once Netea said in a statement that “it seems like BCG vaccine create bookmarks for the immune system to be used later in life”. However, WHO does not approve BCG vaccination for the prevention of COVID-19 as there is no evidence that the Bacille Calmette-Guérin vaccine (BCG) protects people against infection with COVID-19 virus and the trials of this vaccine addressing that question is underway. On the other hand, WHO continues to mention neonatal BCG vaccination in countries or settings with a high incidence of tuberculosis. In this span of time, when we are eagerly waiting for the specific COVID-19 vaccination, we can use BCG which is an existing, available and safe vaccine to elevate host immunity and there is prediction that it may come as a tool to fight against COVID-19 in future. Till then, social distancing, isolating and testing cases are the need of an hour. By implementing these objectives only, we can manage to stop this pandemic of Corona virus.

Reference:-

  1. Worldometer 2020[Cited 2020 12 May 2020]. Available from: https://www.worldometers.info/coronavirus/
  2. Biering-Sørensen, S., Aaby, P., Lund, N., Monteiro, I., Jensen, K. J., Eriksen, H. B., ... & Benn, C. S. (2017). Early BCG-Denmark and neonatal mortality among infants weighing< 2500 g: a randomized controlled trial. Clinical Infectious Diseases65(7), 1183-1190.
  3. Hegarty, P. K., Kamat, A. M., Zafirakis, H., & Dinardo, A. (2020). BCG vaccination may be protective against Covid-19. preprint.
  4. Worldometer 2020[Cited 2020 12 May 2020]. Available from: https://www.worldometers.info/coronavirus/country/us/
  5. Economic Times 2020[Cited 2020 2 April 2020]. Available from: https://www.bloomberg.com/news/articles/2020-04-02/fewer-coronavirus-deaths-seen-in-countries-that-mandate-tb-vaccine
  6. Biospectrum,2020[Cited 2020 27 April 2020].Available from: https://www.biospectrumasia.com/news/37/15850/cansino-bio-enrols-for-ph-2-trial-of-covid-19-vaccine.html
  7. India Today 2020[Cited 2020 27 April 2020].Available from: https://www.indiatoday.in/science/story/novel-coronavirus-vaccines-human-trials-timelines-who-list-april-update-1671715-2020-04-27
  8. Precisions Vaccinations 2020[Cited 2020 28 April 2020]. Available from: https://www.precisionvaccinations.com/vaccines/ino-4800-dna-coronavirus-vaccine
  9. China Global Television Network(CGTN), 2020[Cited 2020 7 May 2020]. Available from: https://news.cgtn.com/news/2020-05-07/First-COVID-19-vaccine-test-on-animals-successful-Qi8WFGpvY4/index.html
  10. National Institute of Health(NIH) 2020[ Cited 2020 16 March 2020]. Available from: https://www.nih.gov/news-events/news-releases/nih-clinical-trial-investigational-vaccine-covid-19-begins.

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