Supply shortage expected for ProQuad vaccine

Following up on this post from March regarding possible shortages of varicella-containing vaccines, this announcement in MMWR last week alerted readers that Merck's ProQuad (a measles, mumps, rubella, and varicella combination vaccine) would be unavailable beginning in July through at least the end of 2007.

With varicella vaccine limited in supply, Merck is prioritizing production of its stand-alone chickenpox vaccine for children and its new shingles vaccine for adults -- both of which are varicella vaccines -- ahead of ProQuad. With its MMR vaccine still available, no children should go unprotected as a result of this temporary shortage, but an additional injection will be needed to provide full protection against the four infections, as this AP story on the announcement explains.

While this news is more of an inconvenience than a serious concern for physicians or patients, it does illustrate the vulnerability of a system in which a vaccine is produced by a single manufacturer, as is the case for many in the United States.