Woman contracts world's deadliest virus after unknowingly being given the wrong vaccine

Importance Score: 65 / 100 🔴

Woman Develops Severe Tuberculosis Infection After Receiving Incorrect Vaccine

In a medical error, a healthy 30-year-old woman experienced a severe case of tuberculosis (TB), one of the world’s most lethal infectious diseases, after being administered the tuberculosis vaccine instead of the intended measles, mumps, and rubella (MMR) immunization. This incident underscores the critical importance of proper medical procedures in vaccine administration and highlights the potential complications arising from vaccine errors. The patient required six months of treatment to recover from the ensuing TB infection.

Medical Mistake Leads to Unexpected Health Crisis

The patient visited a clinic to receive a routine MMR vaccine. However, due to an error by the healthcare provider, she was mistakenly injected with the Bacillus Calmette-Guérin (BCG) vaccine, which is designed to prevent tuberculosis. Tuberculosis remains a global health crisis, responsible for an estimated 1.2 million deaths annually.

Rare Complication Following Vaccine Error

Typically, the BCG vaccine is administered to infants shortly after birth. Adverse reactions to the BCG vaccine are uncommon, especially in healthy adults. Medical literature indicates that severe complications occur in approximately 1 to 10 percent of recipients. These complications can range from mild reactions, such as blisters and swelling at the injection site, to serious conditions including lesions in vital organs and widespread infection.

Diagnosis and Treatment of Adverse Reaction

In this case, the patient, a resident of Ireland, developed an abscess with pus discharge at the injection site on her arm. Initially, medical professionals suspected inflamed connective tissue. However, after weeks of investigation, tests on the pus revealed the presence of tuberculosis-causing bacteria. It was determined that the bacteria strain was likely derived from cattle, the weakened form of which is used in the BCG vaccine.

Incorrect Administration Route Contributes to Infection

The BCG vaccine was improperly administered intramuscularly – injected into the muscle – instead of intradermally – under the skin. Unlike the MMR vaccine which contains viruses, the BCG vaccine contains live bacteria. Injecting the BCG vaccine into muscle tissue allowed the bacteria to spread without the intended localized immune response, leading to a significant infection in the deltoid muscle.

Doctors reporting on the case stated, ‘Intramuscular administration of the BCG vaccine is a known error that can result in rare but preventable complications, even in individuals with healthy immune systems.’ They suggested that ‘confusion between the BCG vaccine and the MMR vaccine’ was a plausible explanation for the administration error.

Mechanism of Complication

The recommended administration method for the MMR vaccine involves intramuscular injection to facilitate a slower replication of weakened viruses and stimulate a robust immune response. Conversely, the TB vaccine, containing weakened Mycobacterium bovis bacteria, should be injected just beneath the skin. This intradermal route triggers a local immune response, controlling the bacteria and establishing immunity without systemic spread.

When the BCG vaccine is injected into muscle, the bacteria can proliferate more readily. In this patient, the misadministration led to an abscess in her arm. While rare, particularly in adults, such adverse effects are more frequently observed in pediatric populations.

Range of Potential Adverse Effects

Medical professionals caution that potential adverse effects from BCG vaccine misadministration can include:

  • Injection-site abscesses
  • Inflammation of lymph nodes
  • Chronic bone pain and mobility issues
  • Systemic infection with fever, fatigue, and enlarged organs

Successful Recovery Following Treatment

The woman received treatment with anti-TB medications, proving effective in her case. Doctors reported her full recovery, with no further symptoms six months after starting treatment. Three months into treatment, the abscess had significantly reduced in size.

Unusual Case Highlights Importance of Medical Precision

Medical professionals emphasized the unusual nature of this case, as complications from BCG vaccination are typically rare and primarily observed in infants or immunocompromised individuals. This patient, however, was a healthy adult, highlighting the potential for serious adverse events even in low-risk individuals when vaccine administration errors occur.

The case report, published in the American Journal of Case Reports, underscores that injection errors are a primary cause of severe reactions to the BCG vaccine. The National Institutes of Health (NIH) has also documented a similar case involving an infant who developed complications from an incorrectly administered BCG vaccine, further emphasizing the importance of precise vaccine delivery.

While localized abscesses are generally not fatal, untreated infections spreading throughout the body can become life-threatening in a significant percentage of cases. This incident serves as a critical reminder of the necessity for rigorous adherence to medical protocols in vaccine administration to prevent patient harm.


🕐 Top News in the Last Hour By Importance Score

# Title 📊 i-Score
1 Most new electric cars to be hit with £2,125 'luxury' tax under new VED rules from today 🟢 85 / 100
2 UK business secretary denies free speech issue featured in US tariff talks 🔴 75 / 100
3 Sky News halted for Keir Starmer 'breaking news' as he issues warning to Trump 🔴 75 / 100
4 The 'Mona Lisa of pigeons' is among five racing birds valued £625,000 stolen by gang – as the sport is rocked by 'explosion' of thefts 🔴 72 / 100
5 Gaunt, dazed and hollow-eyed Justin Bieber films disturbing livestream triggering Hailey Bieber drama 🔴 70 / 100
6 The vitamin that can put a stop to agonising night-time leg cramps: Ask the GP DR MARTIN SCURR 🔵 55 / 100
7 The Revolving Restaurant Is Back Again (and Again) 🔵 45 / 100
8 9 foods you should actually be storing in the fridge (but you never do) 🔵 45 / 100
9 New Zealand Rugby and Ineos settle sponsorship contract dispute 🔵 45 / 100
10 Pete Davidson Brings Elsie Hewitt to Scotland for Dave Navarro's Wedding 🔵 35 / 100

View More Top News ➡️