Merck Warns of Upcoming Shortage of MMRV Vaccine

Pharmaceutical manufacturer Merck & Co. Inc. has projected that, beginning in July, current supplies of its measles-mumps-rubella-varicella, or MMRV, vaccine would be depleted, possibly resulting in back orders for the combination vaccine in the coming months. The company expects the vaccine to remain unavailable through the rest of 2007.

Merck officials attribute the pending shortage of the vaccine, sold as ProQuad, to lower-than-expected amounts of varicella-zoster virus, or VZV, in recently manufactured bulk vaccine lots.

According to a "Notice to Readers" in the May 11 Morbidity and Mortality Weekly Report, the company notified the CDC about the pending shortfall in February. At that time, Merck officials opted to prioritize production of the company's varicella-only vaccine, Varivax, and its newly approved zoster vaccine, Zostavax, over production of ProQuad. The company has since been using its available supply of VZV to manufacture those other two products.

For family physicians and their patients, the upshot of the announcement is that, for at least several months, two immunizations (Merck's measles-mumps-rubella vaccine, sold as M-M-R II, and Varivax) rather than one will be required to cover all four diseases. At this point, according to Trevor Stone, AAFP private-sector advocacy specialist, it's not clear whether that requirement will prove to be boon or bane for FPs' bottom lines.

Despite the fact that "the ordering, storing and administering are made more complex with doubling the number of biologics necessary to meet patients' needs," Stone said, FPs still could come out ahead on the deal. "Given that an additional administration code can be billed, it may work out in a positive way for practices, provided that the additional payment exceeds any extra costs of the vaccine and related costs."

In fact, according to the CDC Vaccine Price List, the per-dose purchase price for the combination vaccine ProQuad -- $124.37 -- somewhat exceeds the cost of purchasing the two vaccines M-M-R II and Varivax separately -- $44.84 and $74.56, respectively -- for a difference of $4.97.

According to the MMWR notice, Merck expects to continue to meet provider demands for Varivax and M-M-R II to "fully implement the recommended immunization schedule."

Consult the Recommended Childhood Immunization Schedule 2007 (PDF file: 1 page / 89 KB. More about PDFs.) and the Recommended Adolescent Immunization Schedule 2007 (PDF file: 1 page / 89 KB. More about PDFs.) on the AAFP Immunization Resources Web page for details on administration of MMR and varicella vaccines. You also can link to a catch-up schedule from the "Immunization Resources" page.

Regardless of how the financial picture eventually works out for FPs, one aspect of the MMWR announcement seems pretty clear, according to Stone. "Children receiving two shots may not be so appreciative of the predicted shortage," he observed.