Understanding the BCG Vaccine: When to Give It to Your Newborn

The BCG (bacilli Calmette-Guerin) vaccine, named after Albert Calmette, and Camille Guerin, is meant to prevent Tuberculosis (TB) (CDC, 2016). Besides TB, the BCG vaccine also protects against other mycobacterial infections such as leprosy and Buruli ulcer (Oxafor et al., 2022). Of note, the authors have also specified its use in treating bladder cancer (superficial carcinoma of the bladder).

The vaccine contains attenuated live TB-causing bacteria. It is meant to boost one’s immune system by fighting against this bacteria without causing the disease. The vaccine is primarily intended to protect newborns from tuberculosis in children. But it also is given to adolescents and adults 16-35 years old if they have family members with high TB risk or coworkers who are infected with tuberculosis(NHS, 2019).

The BCG Vaccine And What It Protects Against

The BCG vaccine is mostly intended for infants and young children to protect against severe forms of TB such as TB meningitis and military disease during childhood. Though it is generally effective against TB, it is primarily designed for this purpose(CDC, 2016; McKoy, 2022). BCG vaccine is limited in availability, it is only offered to newborns born in countries with a high prevalence of TB(CDC, 2016). Countries like the United States, for instance, do not make it mandatory to administer the vaccine to newborns.

Moreover, because of its variable effectiveness in preventing adult pulmonary TB and also the potential interference with tuberculin skin test reactivity, is not deemed to be a good choice (CD4, 2016). Regardless of these facts, NHS (2019) though has stated that adolescents and adults in the age range between 16 and 35 can get the BCG vaccine. If they or their family members (parents, grandparents) are/were born in a country with high TB rates, or are exposed to this disease in their workplace, for example, engaging with TB patients, etc.

Reasons Why the BCG Vaccine is Recommended for Newborns

According to data found from Royal Children’s Hospital in Melbourne (2018), infants and children should receive the BCG vaccine. It has proven its effectiveness in protecting them from severe TB. Thus, it is a highly recommendable vaccine that can be administered to the newborn from birth itself.

According to Puvacic et al. (2004), the BCG vaccine was also protective against TB meningitis during the neonatal period. Again reinforcing the need to get the newborns BCG vaccinated. A child born in an area, community, or country with a high TB prevalence is more likely to contract TB. Thus BCG vaccination is highly recommended for these newborns, lest they are likely to develop TB meningitis.

Aside from protecting newborns against tuberculosis, the BCG tuberculosis vaccine is also capable of protecting them against other common infections. These include upper respiratory tract infections(URIs), chest infections, and diarrhea, and thus, are known to cast a positive influence on many little lives every year.

Risks and Benefits of the BCG Vaccine for Newborns

Methods for Administering BCG Vaccine in Newborns

Newborns are generally administered the BCG vaccine intradermally, i.e., via an injection into the left upper arm. This will cause an open sore leading to a small scar. The vaccine is made from a weakened strain of the TB bacteria. It is meant to trigger or enhance the newborn’s immunity against the TB bacteria. Hence, it does not cause tuberculosis in the baby instead it makes them immune to this bacteria.

The dosage of the BCG vaccine varies depending on the risk of TB exposure for newborns. As per MSF’s medical guidelines (Medecins Sans Frontieres, 2022), newborns’ eligibility to receive this vaccine is based on specific conditions. With this being stated, the “Appendix 29. BCG vaccine” of this article takes into consideration the following:

There is no proven appropriateness of the time at which newborns should be administered the BCG vaccine. It all depends on how eligible newly-born infants are to receive this vaccine (Pillay et al., 2022). If babies are born in high-TB-prone areas that carry high TB rates, they should be given vaccination a few minutes after birth. Otherwise within 28 days after birth to as long as up to 8-10 weeks will suffice.

Similarly, babies and young children who are immunocompromised, i.e., infected by HIV are not advisable to have the vaccine immediately.

Post-BCG-Vaccine Administration Reaction in Newborns

After receiving the BCG vaccine, newborns typically experience redness and a small bump at the injection site. This will eventually turn into a small ulcer-like or open sore. It will take a few months to heal completely, leaving a small flat scar at the point of injection(RCH, 2018).

However, not all children get this scar upon vaccination, though the absence of one does not indicate the ineffectiveness of the vaccine(NHS, 2019). Since the blister is not seen, this does not signify the need for a re-vaccination. This statement has well elucidated that the administration reaction to the BCG vaccination need not be that ideal-looking lump, scar, or redness to be watched for in every infant.

because there are scenarios in which the BCG injection site results in the formation of abscess in the armpit. BCG Adenitis, as it is medically termed, does call for seeking urgent medical attention. Especially when the procedures, such as fine-needle aspiration of the pus fluid within the abscess, have failed. Then it will be requiring a surgical drain-out (Govindarajan and Chai, 2011).

Special Considerations for Administering BCG Vaccine to Premature Babies

Babies born preterm are exposed to a host of infections, especially because of their underdeveloped immune systems. They need extra care to prevent getting sepsis, an extreme/overreaction to infection often leading to death (March of Dimes, 2023).

Preterm babies require special care and routine health monitoring, particularly when receiving the BCG vaccination. It is unnecessary to mention this, but important to keep in mind. Gagneur et al(2015) through their studies, reported that BCG administration in premature babies is a major concern. As this is highly associated with their undeveloped immune system, making this vaccine not recommendable for them.

Meanwhile, the WHO-recommended vaccination policy has enlisted all babies in developing countries, including those born preterm, where they can be vaccinated upon reaching the chronological age of 40 weeks (ClinicalTrials.gov, 2012). Additionally, it was recommended to utilize the same schedules as usually recommended for term infants when vaccinating preterm infants with BCG. Provided they are administered an additional dose of the hepatitis B vaccine given their reduced immune response and more specifically if their weight is less than 2000 grams.

Possibility of the BCG Vaccine Interfering With Other Vaccines

Up to 5 years of a newborn’s life, they need to be vaccinated routinely with many other immunization drugs. To avoid the prevalent risk of TB, it is advised to give BCG vaccine immediately after birth. There is no evidence that the BCG vaccine affects other live vaccines. But it’s important to make sure that the same syringe is not used again. And to be specially noted that, vaccines should be injected at different locations as Medical professionals recommend this to be practiced.

Consequences of Missing BCG Vaccine in Your Newborn

Missing the BCG vaccination in newborns has major consequences depending on their risk of becoming exposed to TB bacteria. At the same time, eligibility and safety also play a significant role in determining the consequences of missed and delayed BCG vaccines in newborns.

Consequences of Missed BCG Vaccine Based on the Risk Criteria

Pillay et al (2022) state that TB exposure, either through the community or family members at high risk of contracting the disease, determines whether a newborn is eligible for the BCG vaccination. The timely administration of a vaccine can prevent severe childhood tuberculosis. Infants in areas where tuberculosis is common can receive the vaccine upon birth. (NHS, 2019). Similarly, newborns infected with HIV are not eligible to receive the BCG vaccination because of safety concerns and the ineffectiveness of the vaccine in protecting such immunocompromised infants against TB (WHO, 2005).

Secondly, the knowledge that the vaccine causes disseminated BCG disease in HIV-infected infants, places them at an even higher risk of developing disseminated BCG disease. Along with findings from WHO demonstrating severe impairment of the BCG-specific T-cell response (Pillay et al., 2022).

Reports from WHO (2005) indicate that patients receiving HAART (highly active antiretroviral therapy) can be BCG vaccinated without getting the disseminated BCG (dBCG) disease because the therapy has proven effective against the same by decreasing its rate. In HIV-infected HAART-receiving patients vaccinated with BCG, immune reconstitution inflammatory syndrome adversely affects them more than HAART has proven to be beneficial(WHO, 2005). This is why the WHO position paper published in 2021 has relaxed the schedule for HIV-infected children. Allowing them enough time to receive the vaccine till they reach 4-5 years. By this time, they must have had enough of the HAART and have documented a CD4 level greater than 25%. This will deem them clinically and radiologically stable as per studies.

Understanding Immunological Memory and Tuberculosis Risk

Several sources have identified the consequences of missing the BCG vaccine in newborns who risk exposure to TB. Studies conducted by Kagina et al(2009), have conveyed no such concerns with missing or delaying the BCG vaccine in newborns, at least to 10 weeks of age. It is because of this that the likelihood of developing enhanced CD4 T-cell responses increases in newborns.

This further indicates that the body’s immune system grows and acquires an immune memory against this. The term ‘Immunological Memory’ refers to the immune system’s ability to store information regarding a stimulus to gain an effective response to the same stimulus twice(Ratajczak et al., 2018). The secondary immune response that occurs in the process is way higher, quicker, and stronger than the earlier (primary) one.

From these statements, it can be concluded that not only HIV-uninfected infants pose a high risk of contracting tuberculosis. But also people who are immunosuppressed or immunocompromised are exposed to HIV risk.

Of note, it would be appropriate to refer to the figure below, which represents a self-explicable flowchart regarding whether or not children should receive the BCG vaccination.

This information indicates that if your newborn missed his/her BCG vaccination, you need not have to worry. Unless he/she risks exposure to TB he/she can have a delayed vaccination at the time suggested by their pediatrician.

Conclusion

Based on the facts discussed above, related to the BCG vaccine, it could be concluded that this drug is specifically meant for newborns because of its proven protectiveness against contracting the more severe forms of TB, i.e., TB meningitis, and the military disease usually found in children.

For this and other reasons described in this report, it is summarized that although BCG vaccination is only considered for newborns and infants, it is not recommended for every newborn, as mentioned before.

What could be stated at this juncture is that newborns who pose a higher risk for contracting TB, and are residing in an area that presents with high TB incidence rates, should be vaccinated immediately than those in whom the BCG vaccine can be scheduled at a later date, again based on the risk profile.