Welcome to the Vaccines and Immunizations website.
Skip directly to the search box, site navigation, or content.

Department of Health and Human Services
Centers for Disease Control and Prevention

Vaccines & Immunizations

Hib Vaccine Recall and Shortage:
Q&As for Parents

December 20, 2007

Questions and Answers for Parents

Haemophilus influenzae type b vaccine, usually called “Hib” vaccine, is routinely given to babies in the United States to protect them from Hib disease. Hib disease causes meningitis (an infection of the protective lining around the brain and spinal cord) and other serious infections . Hib vaccine has been in routine use in the U.S. for over 20 years, and during that time the number of children who get Hib disease decreased from over 20,000 per year to fewer than 100 per year. Babies should receive three or four doses of Hib vaccine between 2 months and 15 months of age (the number of doses depends on which brand of vaccine is used).

On December 13, 2007, it was announced that certain lots of Hib vaccine from one manufacturer were being recalled as a precautionary measure. As a result, the vaccine is in short supply. CDC is recommending that doctors temporarily stop giving the booster dose of Hib vaccine to healthy children. This is the dose children normally receive at 12-15 months of age. Babies 6 months of age and younger should still get their Hib vaccinations. Certain children are at higher risk for Hib disease. CDC recommends these children continue to receive all recommended doses, including the booster dose.

The Hib vaccine is a safe vaccine. All vaccines are held to the highest standards of safety. They are carefully tested and monitored for safety on an ongoing basis by the companies that produce them as well as by the U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC). This recall is an example of the vaccine safety system at work.


  1. What type of vaccine is being recalled, and why?

There is a recall in the United States for several lots of Haemophilus influenzae type b vaccine, often called “Hib vaccine”, made by Merck & Co. Inc. The doses were distributed throughout the U.S. starting in April, 2007. Two types of Merck’s vaccine are being recalled; one is a Hib vaccine alone and the other is a combination vaccine that includes Hib and hepatitis B vaccine.

No problems have been found with the vaccine itself. The strength and effectiveness of the vaccines are fine. Each of the lots of vaccine that has been recalled passed all routine safety tests before being sent to doctor’s offices and those tests found no contamination. However, the lots of vaccine are being recalled as a precautionary step because Merck cannot guarantee they are completely sterile because there is a remote possibility that a type of bacteria (called “B. cereus”) was on equipment at the time the vaccine was manufactured.

This recall means that doctors’ offices and other clinics need to check the vaccine they have in stock and return any vaccine included in this recall to Merck. The lots that are being recalled in the United States are:

Product Description
Lot #
Expiration Date
PedvaxHIB® 0677U 11 January 2010
PedvaxHIB® 0820U 12 January 2010
PedvaxHIB® 0995U 16 January 2010
PedvaxHIB® 1164U 18 January 2010
PedvaxHIB® 0259U 17 October 2009
PedvaxHIB® 0435U 18 October 2009
PedvaxHIB® 0436U 19 October 2009
PedvaxHIB® 0437U 19 October 2009
PedvaxHIB® 0819U 09 January 2010
PedvaxHIB® 1167U 10 January 2010
COMVAX® 0376U 05 January 2010
COMVAX® 0377U 08 January 2010
Another lot of PedvaxHIB® was also recalled, but it was only used in China.

No other U.S. lots of PedvaxHIB® or COMVAX® and no other Merck products are affected by this recall.

top of page

  1. My child recently received a Hib vaccine. Could he/she have been given recalled vaccine?

At this time, we don’t know how many doses of the recalled Hib vaccine have already been used. The recall involves about 1 million doses of vaccine, so we can assume that some children vaccinated against Hib between April 2007 and December 13, 2007 received vaccine from lots affected by this recall. About 16 million doses of Hib vaccine are distributed in the U.S. each year, so many children who were recently vaccinated received vaccine that is not included in this recall. Even if your child received recalled vaccine, there is no major reason for concern.

  1. What if my child received recalled vaccine? What should I do?

Children who received Hib vaccine from recalled lots do not need to be re-vaccinated. The strength and effectiveness of the vaccines are fine, and the vaccinated children will have the same degree of protection from Hib disease as those vaccinated with the non-recalled lots.

Each of the lots of vaccine that has been recalled passed all routine safety tests before being sent to doctor’s offices, and those tests found no contamination. In addition, the recalled vaccines have not been found to have caused problems in children who received them. However, in the highly unlikely event that a child did receive vaccine that contained B. cereus, there may be a risk of developing infection at the injection site or a more general infection. Children with weakened immune systems may be at greater risk for these infections. These infections would be expected to occur soon after vaccination (within about one week).

As always recommended after vaccination, parents of children vaccinated against Hib in the past week should watch for any signs of infection (such as marked redness and swelling at the injection site) and contact their child’s doctor if such signs occur.

top of page

  1. My child is due for a Hib vaccine soon. Will our doctor’s office have it?

As a result of this recall, there may be healthcare providers who have none or very little Hib vaccine at this time. These doctors may need to delay Hib vaccinations for their patients until they get more vaccine.

Depending on the brand of Hib vaccine that your doctor uses, your child should receive two doses of Hib vaccine at ages 2 and 4 months or three doses at ages 2, 4, and 6 months. Normally, your child would then be given a booster dose at 12-15 months of age. If your child is 6 months of age or younger and their Hib vaccine was delayed, it is important that you bring them back to be immunized as soon as your provider has vaccine.

  1. Will my one-year-old receive Hib vaccine at his upcoming doctor’s appointment? I heard that doctors are being told not to give the booster dose of Hib vaccine.

CDC is asking all doctors to temporarily stop giving healthy children 12-15 months of age booster doses of Hib vaccine. We do not believe this will put your child at higher risk of getting Hib disease. Even though children 12-15 months of age will not be receiving booster doses of Hib vaccine at this time, they should still be taken for their well-child visit so they can receive the other vaccines and routine care that they are due for and be seen by a healthcare provider as scheduled.

If your child is at higher risk for Hib disease (see question 8 below) he should receive all the recommended doses of Hib vaccine, including a booster dose.

  1. My child is due for a Hib vaccine soon, but this recall has me concerned. Is Hib vaccine safe?

It is understandable that this recall might raise concern among some parents. We want to emphasize to parents that this recall was a precautionary step, no problems have been found with the vaccine itself, and the vaccines have not been found to have caused problems in children who received them. Providers have been instructed to stop using recalled vaccine immediately.

The Hib vaccine is a safe vaccine. Rarely, serious side effects result from vaccination. This very low risk of possible side effects should be weighed against the benefit of protection the vaccine offers against Hib disease.

If you have concerns or questions about vaccinations for yourself or your child, you should discuss them with your healthcare provider. If you have a serious or unexpected adverse reaction after receiving any vaccine, report it to your health care provider. Any potentially vaccine-related adverse events should also be reported to the Vaccine Adverse Event Reporting System (VAERS) at 1-800-822-7967 (or at www.vaers.hhs.gov).

top of page

  1. What is Hib disease? Why do we vaccinate against it?

Haemophilus influenzae type b (called “Hib”) is a type of bacteria that can cause meningitis (an infection of the protective lining around the brain and spinal cord), pneumonia (lung infection), epiglottitis (a severe throat infection), and other serious infections.

These diseases can be serious in children under age 1, but there is little risk of getting the disease after age 5. Before routine Hib vaccination, Hib infections struck about 1 in every 200 children under age 5 years old, killing about 1 in 20 of these children. The vaccine is highly effective at preventing Hib disease.

  1. Are some children at higher risk for Hib?

Yes. Children at increased risk for Hib include: children with sickle cell disease, leukemia and malignant neoplasms (tumors), HIV and certain other conditions that weaken the immune system, children who do not have spleens or have spleens that do not work correctly (a condition called “asplenia”), as well as American Indian and Alaska Native children. Vaccinating these children according to the recommended schedule is a high priority.

  1. What are the chances that my child will get a Hib infection if he or she cannot be vaccinated at this time because of the recall?

Fortunately, current immunization rates in the U.S. for Hib vaccine are high. In 2006, about 94% of U.S. children 19-35 months of age were vaccinated against Hib. This means that spread of Hib from child to child at this time is very low. However, experience has shown that we cannot let down our guard against vaccine-preventable diseases such as Hib. If your child’s doctor does delay the next dose of Hib vaccine because of this recall, it is important that you follow-up to obtain the vaccine when it becomes available.

top of page

Non-CDC Link Disclaimer: Links to non-Federal organizations found at this site are provided solely as a service to our users. These links do not constitute an endorsement of these organizations or their programs by CDC or the Federal Government, and none should be inferred. The CDC is not responsible for the content of the individual organization web pages found at these links.

This page last modified on December 20, 2007
Content last reviewed on December 20, 2007
Content Source: National Center for Immunization and Respiratory Diseases

Quick Links

Safer Healthier People

Centers for Disease Control and Prevention 1600 Clifton Rd, Atlanta, GA 30333, U.S.A
Public Inquiries: 1-800-CDC-INFO (232-4636); 1-888-232-6348 (TTY)

Vaccines and Immunizations