Available Vaccines
Passive Immunisation
Introduction
Passive immunisation involves the administration of antibodies (immunoglobulins, primarily IgG) pooled from blood donors to provide temporary protection in the following situations:
- Unimmunised individuals exposed to an infection.
- Individuals infected with a disease for which active immunisation is unavailable.
The protective effect of the administered immunoglobulin is immediate; however, the protection may be incomplete and short-lived, lasting for several weeks up to 3–4 months.
There are 2 types of immunoglobulins that will be discussed in this guideline:
- Normal (non-specific) human immunoglobulin: derived from unselected donors.
- Hyperimmune (specific) immunoglobulin: derived from selected donors
Potential side effects of both immunoglobulins include malaise, chills, fever, headache, nausea, facial flushing and, rarely, anaphylaxis.
I Normal Human Immunoglobulin (NHIg)
Normal human immunoglobulin (NHIg) is derived from pooled plasma of blood donors and contains antibodies against microbial agents commonly circulating in the general population, including hepatitis A, rubella, measles, and other prevalent viruses. NHIg provides immediate, temporary protection when administered within 72 hours (3 days) of exposure, with the protective effect lasting for several weeks. It is administered via intramuscular injection.
Important considerations with live vaccines:
- NHIg interferes with the immune response to live vaccines (except for yellow fever) for up to 3 months.
- Ideally, live vaccines should be administered at least 3 weeks before, or delayed for 3 months after, NHIg administration to ensure vaccine effectiveness.
Currently, passive immunisation with NHIg remains an important preventive measure for measles and hepatitis A among non-immune contacts in countries with low disease incidence. It is also recommended for non-immune pregnant contacts of rubella. There are variations in practice regarding the use of passive immunisation for measles, hepatitis A, and rubella contacts in high-income countries. In Australia, post-exposure administration of immunoglobulin has not been shown to provide benefit. In contrast, in the United Kingdom and New Zealand, the use of passive immunisation may be considered for pregnant women exposed to rubella, particularly in situations where termination of the pregnancy is not an option.
Indications for Normal Human Immunoglobulin (NHIg)
A. Hepatitis A
NHIg is indicated for the prevention of hepatitis A infection in:
- Close contacts of confirmed cases, especially when identification is delayed beyond 7 days or if they are at high risk of severe disease.
- Immunocompromised individuals, in whom the antibody response to vaccination may be suboptimal.
NHIg is most effective if given within 72 hours of exposure.
Specific recommendations:
- Healthy individuals aged 12 months–40 years: Single-antigen hepatitis A vaccine is preferred due to long-term protection, ease of administration, and comparable efficacy to NHIg.
- Individuals ≥40 years: NHIg is preferred due to limited data on vaccine performance in this age group and increased risk of severe disease. The decision to use vaccine or NHIg should consider the individual’s risk of HAV transmission.
- If NHIg is unavailable, hepatitis A vaccine may be used as an alternative.
- NHIg is recommended for:
- Immunocompromised individuals
- Individuals with chronic liver disease
- Individuals with contraindications to the hepatitis A vaccine
B. Measles
NHIg may be administered to prevent or attenuate measles infection in:
- Immunocompromised adults and children following close contact with a confirmed measles case.
- Non-immune pregnant women exposed to confirmed cases or during local outbreaks.
NHIg is most effective within 72 hours but can still be considered up to 6 days post-exposure.
For individuals with normal immunity who do not fall into the above categories and are not fully immunised, measles vaccination is preferred.
C. Rubella
Post-exposure NHIg does not prevent rubella infection and is not routinely recommended for pregnant women exposed to rubella.
However, it may reduce the severity of clinical illness in the mother and possibly lower foetal risk and may be considered only when pregnancy termination is not an option.
- Serological follow-up is essential to determine whether infection occurred despite administration.
Table 28.1 Overview of Normal Human Immunoglobulin (NHIg) and Clinical Application
II Hyperimmune Immunoglobulin
Hyperimmune immunoglobulin is derived from the pooled plasma of selected donors with high antibody titres against specific pathogens. It contains high concentrations of antibodies targeting particular infectious agents, providing immediate, temporary protection in specific high-risk exposures or in individuals for whom active immunisation is not feasible or effective. The protective effect of administered specific immunoglobulin is immediate, but protection may be incomplete and short-lived, typically lasting for several weeks up to 3–4 months.
Hyperimmune immunoglobulin products are available for various infections, including hepatitis B, varicella-zoster, rabies, and tetanus, and are used for post-exposure prophylaxis or treatment in specific clinical scenarios.
Potential side effects are similar to those of NHIg and may include malaise, chills, fever, headache, nausea, facial flushing, and, rarely, anaphylaxis.
Table 28.2 Overview of Specific Immunoglobulin and Clinical Considerations
Passive Immunisation for Immunocompromised Hosts (ICH)
Immunocompromised hosts (ICH) are at increased risk of severe infections due to their impaired ability to mount an adequate immune response. Passive immunisation using immunoglobulin provides immediate, temporary protection in these individuals, helping to prevent infections or reduce the severity of disease. Intravenous normal human immunoglobulin (IV NHIg) is used for replacement therapy in patients with primary or secondary hypogammaglobulinemia, while intramuscular NHIg may be administered for post-exposure prophylaxis against specific infections such as measles and hepatitis A in immunocompromised patients.
Table 28.3 Passive Immunisation Recommendations for Immunocompromised Hosts (ICH)
References
- Baxter, D. (2007). Active and passive immunity, vaccine types, excipients and licensing. Occupational Medicine, 57(8), 552-556. https://doi.org/10.1093/occmed/kqm110
- Perez, E. E., Orange, J. S., Bonilla, F., Chinen, J., Chinn, I. K., Dorsey, M., El-Gamal, Y., Harville, T. O., Hossny, E., Mazer, B., Nelson, R., Secord, E., Jordan, S. C., Stiehm, E. R., Vo, A. A., & Ballow, M. (2017). Update on the use of immunoglobulin in human disease: A review of evidence. The Journal of allergy and clinical immunology, 139(3S), S1–S46. https://doi.org/10.1016/j.jaci.2016.09.023
- Advisory Committee on Immunization Practices (ACIP) Centers for Disease Control and Prevention (CDC) (2007). Update: Prevention of hepatitis A after exposure to hepatitis A virus and in international travelers. Updated recommendations of the Advisory Committee on Immunization Practices (ACIP). Morbidity and mortality weekly report, 56(41), 1080–1084. https://pubmed.ncbi.nlm.nih.gov/17947967/
- Young, M. K., & Cripps, A. W. (2013). Passive immunization for the public health control of communicable diseases: current status in four high-income countries and where to next. Human vaccines & immunotherapeutics, 9(9), 1885–1893. https://doi.org/10.4161/hv.25311