Researchers in Boston, Australia and the Netherlands are conducting trials to investigate the potential of the Bacille Calmette-Guérin vaccine (BCG) to combat the new coronavirus—despite officials from the World Health Organization (WHO) saying there is no evidence it will help.
While the race is on to develop a vaccine to target the virus that causes COVID-19, virologists say it could be a long while before one is ready. In the meantime, researchers are turning to existing medications, from the antimalarial drug hydroxychloroquine, to antiparasitic treatment Ivermectin.
The latest in the media spotlight is a century-old vaccine for tuberculosis—BCG. The vaccine was developed in Paris in the 1920s, though variations exist across the world and its effectiveness at preventing TB has been debated.
On the back of preliminary studies linking lower rates of COVID-19 to BCG usage, scientists in different countries have commenced clinical trials to find out if the vaccine can prevent or reduce COVID-19 related symptoms.
In Australia and the Netherlands, BCG studies involving health care workers are due to be completed by March 2022 and Christmas 2020 respectively.
In the U.S., the Faustman Lab headed by Dr. Denise Faustman at Massachusetts General Hospital in Boston, is preparing a clinical trial for “at risk” health care workers. The purpose is to test BCG’s potential in protecting against COVID-19 and related complications.
But medical experts have warned there is reason to be cautious. Studies suggesting countries with mandatory BCG programs have lower rates of COVID-19 are yet to be peer-reviewed—meaning they have not been checked by experts in their field—and may have serious limitations.
While there is experimental evidence suggesting BCG may have non-specific effects on the immune system that can help ward off other pathogens—including those responsible for malaria—the WHO stresses “these effects have not been well characterized and their clinical relevance is unknown.”
Madhukar Pai, Director of McGill University’s International TB Centre, explained in an article for Forbes that ecological studies suggesting BCG could protect against COVID-19 have major limitations. They may not take into account differing levels of testing or factors that may skew the results and exagerate the role of BCG, for example.
Those carried out weeks ago may be out-of-date and misleading in a rapidly unfolding situation like a pandemic. Pai highlights a 40-fold increase in cases in India (where BCG is mandatory) between March 21 when there were 195 cases and April 11 when there were 8,446.
“As a TB researcher, I would be thrilled if BCG worked against COVID-19,” he wrote, adding the hypothesis is worth chasing. “The good news is that rigorous trials are getting underway, to settle the issue, one way or another.”
The WHO has said there is no evidence the vaccine can protect people from the virus that causes COVID-19 and officials do not recommend the BCG vaccination as a preventative treatment for the new coronavirus. The organization has said they will reassess the evidence from the two trials during a review when it becomes available.
Tero Vesalainen/iStock
“In some ways, the hype around BCG is analogous to the hype and hope around choloroquine and hydroxychloroquine (HCQ) for COVID-19,” Pai wrote. News of the trials comes shortly after reports that the U.S. Centers for Disease Control and Prevention (CDC) removed advice concerning the prescription of hydroxychloroquine to treat COVID-19, which followed the decision to stockpile 29 million pills of the antimalarial drug.
“The whole world is looking for good news and silver bullets. This is understandable. While this may change in future, currently, there is no evidence to support the clinical use of either BCG or HCQ for COVID-19, except in carefully controlled clinical trials,” said Pai.
The infographic below, provided by Statista, shows the number of COVID-19 cases that have been confirmed as of April 15, 2020.
Statista
Centers for Disease Control and Prevention Advice on Using Face Coverings to Slow Spread of COVID-19
- CDC recommends wearing a cloth face covering in public where social distancing measures are difficult to maintain.
- A simple cloth face covering can help slow the spread of the virus by those infected and by those who do not exhibit symptoms.
- Cloth face coverings can be fashioned from household items. Guides are offered by the CDC. (https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/diy-cloth-face-coverings.html)
- Cloth face coverings should be washed regularly. A washing machine will suffice.
- Practice safe removal of face coverings by not touching eyes, nose, and mouth, and wash hands immediately after removing the covering.
World Health Organization advice for avoiding spread of coronavirus disease (COVID-19)
Hygiene advice
- Clean hands frequently with soap and water, or alcohol-based hand rub.
- Wash hands after coughing or sneezing; when caring for the sick; before, during and after food preparation; before eating; after using the toilet; when hands are visibly dirty; and after handling animals or waste.
- Maintain at least 1 meter (3 feet) distance from anyone who is coughing or sneezing.
- Avoid touching your hands, nose and mouth. Do not spit in public.
- Cover your mouth and nose with a tissue or bent elbow when coughing or sneezing. Discard the tissue immediately and clean your hands.
Medical advice
- Avoid close contact with others if you have any symptoms.
- Stay at home if you feel unwell, even with mild symptoms such as headache and runny nose, to avoid potential spread of the disease to medical facilities and other people.
- If you develop serious symptoms (fever, cough, difficulty breathing) seek medical care early and contact local health authorities in advance.
- Note any recent contact with others and travel details to provide to authorities who can trace and prevent spread of the disease.
- Stay up to date on COVID-19 developments issued by health authorities and follow their guidance.
Mask and glove usage
- Healthy individuals only need to wear a mask if taking care of a sick person.
- Wear a mask if you are coughing or sneezing.
- Masks are effective when used in combination with frequent hand cleaning.
- Do not touch the mask while wearing it. Clean hands if you touch the mask.
- Learn how to properly put on, remove and dispose of masks. Clean hands after disposing of the mask.
- Do not reuse single-use masks.
- Regularly washing bare hands is more effective against catching COVID-19 than wearing rubber gloves.
- The COVID-19 virus can still be picked up on rubber gloves and transmitted by touching your face.
