If you’ve been exposed to the virus, hepatitis B immune globulin injections (HBIG) can offer short-term protection.

Unlike the hepatitis B vaccine, which is required for longer and broader protection against the virus, immunoglobulin injections are typically only used after possible exposure.

For example, if you’re a healthcare professional and are accidentally pricked with a needle during work, HBIG can help reduce your risk for potential infection.

HBIG can also be used to protect newborns whose birthing parent has or is at risk for the virus, as well as people who receive a liver transplant.

The injection contains antibodies found in the plasma of donors who are already vaccinated against hepatitis B. This injection of antibodies works against any early signs of hepatitis B infection, effectively squashing the virus.

HBIG only requires one dose injected into your muscle. By comparison, a full course of the hepatitis B vaccine involves 3–5 intramuscular injections over the course of several months.

The ideal timeline for treatment depends on the method of possible exposure:

  • If you have or are at risk for hepatitis B and are planning for childbirth, HBIG should be administered to your newborn within 24–48 hours of delivery.
  • If you experienced an accidental needle prick injury or used an unsterilized needle, HBIG should be administered within 7 days of suspected exposure.
  • If bodily fluids were exchanged during partnered sexual activity, HBIG should be administered within 14 days of suspected exposure.

In all cases, and for maximum effectiveness, experts recommend that those who have been exposed to hepatitis B receive the immunoglobulin injection as soon as possible.

A healthcare professional may recommend immunoglobulin injections if you have:

  • been pricked by a sharp medical object of unknown origin
  • used an unsterilized needle or shared a needle with others
  • had sexual contact with a person who has hepatitis B or whose STI status is unknown
  • otherwise had contact with another person’s blood, semen, or other bodily fluids
  • recently received a liver transplant or have an upcoming liver transplant procedure

Although HBIG is usually well tolerated, side effects are possible. A doctor may ask you to sit in the lobby or other waiting area for 10 to 15 minutes afterward to monitor your symptoms.

You may experience the following:

Research in 2018 found that side effects such as headaches can last between 1 and 3 days.

In rare cases, blood clots and other adverse effects are possible after receiving immunoglobulin injections. These uncommon reactions usually occur within 48 hours of the injection.

Your risk of blood clots increases if you have a history of thrombosis and are 45 years and older.

While the vaccine is often given shortly after or, in some cases, at the same time as an immunoglobulin injection, the two therapies serve different purposes.

The vaccine provides long-term protection against hepatitis B. Unless you are a non-responder to the vaccine — meaning you’re someone who received it and it did not give you the antigens needed to prevent infection — it will give you lifelong protection.

In comparison, hepatitis B immunoglobulin injections will provide about 3–6 months of protection.

The immunoglobulin injection is only used after potential exposure to the hepatitis B virus to prevent infection. In addition to reducing the risk of infection, the injection can also reduce symptoms.

If you aren’t vaccinated against hepatitis B or are unsure of your vaccination status, HBIG can help reduce your risk of developing hepatitis B after suspected exposure.

The immunoglobulin injection can provide short-term protection against the virus, but it must be administered within 1–2 weeks in order to be effective.

Reach out to a healthcare professional if you think you may have been exposed to hepatitis B and could benefit from HBIG.

Your doctor can help you access treatment and, if needed, hepatitis B vaccination to further reduce your risk.

Photo by Jaecy Bells

John Loeppky is a disabled freelance journalist who currently resides in Saskatoon, Saskatchewan, Canada on Treaty 6 territory. His work has appeared for CBC, FiveThirtyEight, Defector, Insider, and a host of other publications. He can be reached at John@Jloeppky.com and his goal in life is to have an entertaining obituary to read.