From the Guidelines
Low IgG levels for measles indicate insufficient immunity against the virus, requiring prompt action to prevent infection, and the most effective approach is to administer the MMR (measles, mumps, rubella) vaccine to boost immunity, as recommended by the Advisory Committee on Immunization Practices (ACIP) 1.
Key Considerations
- The standard regimen for adults with no or uncertain vaccination history is two doses of MMR vaccine given at least 28 days apart.
- Each dose contains attenuated measles virus that stimulates the immune system to produce protective antibodies without causing disease.
- For individuals with immunodeficiency disorders causing persistently low IgG, immune globulin might be recommended instead, typically given as a 400 mg/kg dose intravenously, as suggested by studies 1.
Special Cases
- Severely immunocompromised patients and other symptomatic HIV-infected patients who are exposed to measles should receive immune globulin (IG) prophylaxis regardless of vaccination status, as they may not be protected by the vaccine 1.
- For patients receiving intravenous immune globulin (IGIV) therapy, a standard dose of 100-400 mg/kg should be sufficient to prevent measles infection after exposures occurring within 3 weeks after administration of IGIV 1.
Post-Vaccination Protocol
- After vaccination, allow 4-6 weeks for antibody development before retesting IgG levels to confirm immunity.
- Measles is highly contagious and can cause serious complications, so establishing immunity is essential, especially before international travel or during local outbreaks.
- The vaccine is generally very safe, with mild side effects like soreness at the injection site or low-grade fever that resolve quickly.
From the Research
Measles Low IgG
- Low IgG levels against measles can be caused by various factors, including vaccination response and immune system function 2, 3.
- Studies have shown that a significant proportion of children may not develop adequate IgG levels against measles after primary vaccination, highlighting the need for a second dose to raise protection levels 2.
- The immunogenicity and efficacy of measles vaccination can be influenced by factors such as age, vaccine type, and immune status 4, 3.
- In HIV-infected individuals, the response to measles vaccination may be impaired, with lower antibody levels and decreased seroprotection rates compared to uninfected individuals 3, 5.
- Early measles vaccination in children born to HIV-infected mothers has been shown to be safe and immunogenic, with high seroresponse rates and adequate antibody levels 6.
Factors Influencing IgG Levels
- Age at vaccination: Earlier vaccination may not provide adequate protection due to maternal antibody interference 4.
- Vaccine type: Different vaccine types and schedules may influence immunogenicity and efficacy 4, 6.
- Immune status: HIV infection can impair the response to measles vaccination, leading to lower antibody levels and decreased seroprotection rates 3, 5.
- Maternal antibodies: Presence of maternal antibodies can interfere with vaccine response and reduce seroprotection rates 6.