Last Updated on November 26, 2025 by Bilal Hasdemir

The BCG vaccine is made from a weakened form of Mycobacterium bovis. It was created by Albert Calmette and Camille Guérin in the early 1900s. It helps protect against tuberculosis (TB), a serious disease that affects millions globally.

At Liv Hospital, we focus on top-notch, evidence-based care and health prevention. The BCG vaccine is key in fighting TB worldwide, mainly in high-risk areas. We ensure your safety and health by sticking to the latest medical guidelines.

Key Takeaways

• The BCG vaccine is a live, attenuated form of Mycobacterium bovis.
• It was developed by Albert Calmette and Camille Guérin.
• The vaccine is mainly used to fight tuberculosis.
• BCG vaccination is vital in areas with high TB rates.
• Liv Hospital follows evidence-based vaccination protocols.

The History and Development of BCG Vaccine

The BCG vaccine has been a key tool in fighting tuberculosis for over a century. It was created by dedicated scientists who pushed the boundaries of what was possible.

The Work of Albert Calmette and Camille Guérin

Albert Calmette and Camille Guérin, two French scientists, started working on the BCG vaccine in the early 1900s. They worked hard to make a safe vaccine from Mycobacterium bovis. It took them 13 years and 230 subcultures to get it right.

Their hard work paid off in 1921 with the first human trial. The vaccine has been used worldwide, helping fight tuberculosis in many places.

Evolution of the Vaccine in the 20th Century

Over the 20th century, the BCG vaccine went through many changes. New strains were developed, and countries set their own vaccination rules. These changes were important milestones in the vaccine’s history.

The story of the BCG vaccine shows the power of teamwork and innovation. Knowing its history helps us understand its importance in today’s global health efforts.

What Is Bacillus Calmette-Guérin Vaccine?

BCG is a live, weakened vaccine that fights tuberculosis. It’s made from Mycobacterium bovis, a relative of TB-causing bacteria. It mainly protects against TB, a serious lung infection.

For more detailed information on the BCG vaccine, you can visit https://www.vax-before-travel.com/vaccines/bacille-calmette-guerin-bcg-vaccine.

Definition and Basic Composition

The BCG vaccine comes from a weakened Mycobacterium bovis strain. This makes it safe for humans. It’s designed to prevent TB without causing the disease itself.

The vaccine also has additives to keep it stable and long-lasting. It’s given as an injection in the forearm. It helps protect against severe TB, like TB meningitis in kids.

How BCG Differs from Other Vaccines

BCG is unique because it’s a live, weakened vaccine. Unlike other vaccines, it contains live bacteria. This helps it trigger a strong immune response against TB.

“The BCG vaccine’s ability to induce a robust immune response makes it an essential tool in the fight against tuberculosis, particular in regions with high TB prevalence.”

BCG’s effectiveness can vary. It works well against severe TB in kids but not as much in adults. Its protection against pulmonary TB in adults is not consistent.

The Science Behind BCG: How It Works

We dive into the science of the BCG vaccine, revealing how it works. The BCG vaccine, or Bacillus Calmette-Guérin vaccine, has been key in fighting tuberculosis (TB) for nearly a century. It works by creating a specific immunological response that guards against TB.

Mechanism of Action

The BCG vaccine introduces a live, weakened Mycobacterium bovis to the body. This strain is similar to Mycobacterium tuberculosis, the TB-causing bacteria. After being given, the vaccine gets the immune system to fight the bacteria.

The BCG vaccine’s process includes several steps:

• The vaccine is taken in by immune cells called macrophages and dendritic cells.
• These cells break down the vaccine antigens and show them to T-cells, a type of immune cell.
• The T-cells see the antigens as foreign and start an immune fight against them.
• This fight helps protect against future Mycobacterium tuberculosis infections.

Immunological Response to BCG

The BCG vaccine’s effect on the immune system is complex. It involves both innate and adaptive immunity. The vaccine triggers a cell-mediated immune response, which is vital for fighting TB.

Experts say, “The BCG vaccine’s power to create a strong cell-mediated immune response is key to its protection against tuberculosis.”

This response activates various immune cells, like macrophages, T-cells, and natural killer cells. They work together to get rid of the bacteria.

Understanding the BCG vaccine’s science is key to seeing its role in preventing TB. Its power to spark a strong immune response makes it a vital tool in fighting TB worldwide.

Primary Use: Tuberculosis Prevention

The Bacillus Calmette-Guérin (BCG) vaccine is key in fighting tuberculosis. This disease is a big health problem worldwide. It mainly hits the lungs but can affect other parts too. The BCG vaccine helps control TB, mainly in places where it’s common.

Understanding Tuberculosis Disease

Tuberculosis spreads through the air when someone with it coughs or sneezes. It’s caused by Mycobacterium tuberculosis. Not everyone with TB gets sick; some have it but don’t show symptoms. But people with weak immune systems, like those with HIV/AIDS, are more likely to get sick.

How BCG Protects Against TB

The BCG vaccine uses a weak Mycobacterium bovis to start an immune response. This response helps fight M. tuberculosis. It’s very good at preventing serious TB in kids, like TB meningitis.

Target Population for TB Immunization

Who gets the BCG vaccine depends on where you live. In places with lots of TB, all newborns get it. In areas with less TB, it’s for those at high risk, like healthcare workers and kids likely to be exposed.

Knowing how the BCG vaccine helps fight TB shows its importance in health efforts. It’s a big step towards beating TB worldwide.

BCG Vaccine Administration and Dosage

Administering the BCG vaccine needs careful thought about dosage and method. It protects against tuberculosis (TB). Getting it right is key for good immunity.

Standard Vaccination Protocol

The BCG vaccine is given intradermally, usually on the forearm. It’s a single dose. This ensures it works well.

Different Strains and Formulations

There are many BCG vaccine strains, like Danish, French, and Japanese. Each has its own traits. The choice depends on the area and health rules.

Typical Vaccination Schedule

The BCG vaccine schedule varies worldwide. In places with lots of TB, it’s given at birth or early on.

Here’s a look at typical schedules in different areas:

We stick to World Health Organization (WHO) guidelines. They suggest a single dose for infants in high TB areas.

Effectiveness of BCG Against Tuberculosis

The BCG vaccine’s fight against tuberculosis has been studied a lot. It shows a mix of results. The vaccine is used to fight TB, a serious lung disease. We’ll look at how well it works, what affects its success, and how long it lasts.

Varying Protection Rates

Research shows the BCG vaccine’s success against TB varies a lot. It can be anywhere from 0% to 80% effective. This big difference comes from many things like the vaccine type, who it’s given to, and where they live. For example, a study on BCG vaccine found big differences in how well it works in different places.

Factors Affecting Vaccine Efficacy

Many things can change how well the BCG vaccine works. These include genetic differences in people, exposure to certain bacteria, and how the vaccine is made and given. Knowing these can help us use the vaccine better in different places.

Duration of Protection

How long the BCG vaccine protects against TB is also important. Studies say it helps a lot against severe TB in kids, but its protection fades over time. How long it lasts can vary, and giving booster shots is being looked into to keep immunity strong. We keep studying BCG to help public health efforts.

Beyond TB: BCG for Bladder Cancer Treatment

BCG vaccine is now used to fight non-muscle invasive bladder cancer. It was first made to prevent tuberculosis. But, it’s also shown great promise in treating bladder cancer.

Mechanism in Cancer Therapy

BCG vaccine works by boosting the immune system to fight cancer cells. When put directly into the bladder, it sparks an immune response. This response helps kill bladder cancer cells.

This method is very effective for non-muscle invasive bladder cancer (NMIBC). It uses immune cells like macrophages and T lymphocytes to find and destroy cancer cells in the bladder.

Administration Protocol for Cancer

BCG treatment for cancer is different from its use against TB. For bladder cancer, it’s given directly into the bladder through a catheter. The treatment starts with a series of weekly doses, followed by maintenance treatments.

The exact dosage and schedule can change based on how well the patient responds and the doctor’s advice.

Success Rates and Limitations

BCG therapy is very effective in stopping bladder cancer from coming back. It has been shown to greatly lower the risk of tumor recurrence and growth.

BCG therapy is usually safe but can cause side effects. These can range from mild to serious. It’s important to carefully choose who gets BCG and to watch them closely to get the most benefits while avoiding risks.

Side Effects and Contraindications

Let’s dive into the BCG vaccine’s side effects and who should avoid it. The BCG vaccine is key for preventing TB. But, it can cause reactions, from mild to serious.

Common Reactions and Management

Most people get mild side effects from the BCG vaccine. Common issues include:

• Local reactions like redness, swelling, or pain at the injection site.
• Mild fever or feeling a bit off.
• Swollen lymph nodes.

These issues usually go away in a few weeks. But, if they don’t get better or get worse, you should see a doctor.

Rare Adverse Events

Though rare, serious side effects can happen. These include:

1. Severe local reactions that might cause ulcers or abscesses.
2. Disseminated BCG infection, a serious issue where the bacteria spread.
3. Osteitis or osteomyelitis, which are bone infections or inflammation.

These serious issues are more common in people with weak immune systems.

Who Should Not Receive BCG

Some people should not get the BCG vaccine because of the risks. These include:

Healthcare providers must check if the BCG vaccine is right for each person. They look at their medical history and current health.

Knowing the side effects and who should avoid the BCG vaccine helps use it safely and effectively.

Global Usage Patterns and Policies

The BCG vaccine is used in different ways around the world. This shows how TB and health policies vary. The World Health Organization (WHO) helps set these policies.

High TB Burden Countries vs. Low Incidence Regions

In places with lots of TB, babies get the BCG vaccine at birth. This is common in many poor countries where TB is common.

But, in places with less TB, like the United States, things are different. Here, who gets the vaccine depends on their risk, not everyone.

WHO Recommendations

The WHO says all babies in high TB areas should get the BCG vaccine. This helps protect them from severe TB.

In areas with less TB, the WHO suggests making vaccine policies based on local TB risks and how it spreads.

BCG Vaccination in the United States

In the United States, the BCG vaccine isn’t for everyone. It’s mainly for people at high risk, like healthcare workers or kids at risk of drug-resistant TB.

The Centers for Disease Control and Prevention (CDC) gives rules for when to use the BCG vaccine. They focus on protecting those most at risk.

Knowing how the BCG vaccine is used worldwide is key to fighting TB. As TB changes, so will the ways we fight it.

Conclusion: The Future of BCG Vaccination

Understanding the Bacillus Calmette-Guérin (BCG) vaccine is key to its role in global health. For nearly a century, the BCG vaccine has been a major tool against tuberculosis (TB). Its history and development are thanks to Albert Calmette and Camille Guérin.

The future of BCG vaccination will depend on research, global health policies, and TB’s changing patterns. We must tackle the challenges of using an old vaccine today. This includes varying protection rates and the need for new strains or formulas.

We expect research to make the BCG vaccine more effective against TB. It may also help treat other conditions, like bladder cancer. The BCG vaccine’s legacy is not just in the past but also in the future of global health. It will continue to be important in shaping how we immunize.

As global health changes, the BCG vaccine’s future will be shaped by our efforts. We aim to improve vaccine effectiveness, tackle new challenges, and ensure everyone has access to this vital vaccine.

References

1. Medsafe. BCGCSL Data Sheet (New Zealand). https://www.medsafe.govt.nz/profs/datasheet/b/BCGCSLinj.pdf
2. U.S. Food and Drug Administration (FDA). BCG Vaccine Package Insert. https://www.fda.gov/files/vaccines,%20blood%20&%20biologics/published/Package-Insert—BCG-Vaccine.pdf (U.S. Food and Drug Administration)
3. Wikipedia. BCG vaccine. https://en.wikipedia.org/wiki/BCG_vaccine (Wikipedia)
4. Okafor CN. Bacillus Calmette‑Guerin (BCG). StatPearls / NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK538185/ (NCBI)
5. Centers for Disease Control and Prevention (CDC). Bacille Calmette‑Guérin (BCG) Vaccine for Tuberculosis. https://www.cdc.gov/tb/hcp/vaccines/index.html (cdc.gov)