Merck & Co. Inc. issued an update on the status of its vaccine delays and shortages in a letter to physicians.
The company announced that ProQuad (measles, mumps, rubella, and varicella virus vaccine live) will be unavailable for ordering through the rest of 2007, although existing back orders were filled through August. It said it was too early to decide if ProQuad will be available in 2008.
Merck had earlier requested that customers transition from ProQuad to M-M-R II and Varivax (varicella vaccine). The Centers for Disease Control and Prevention continues to report that current projections forecast an adequate supply to implement the recommended immunization schedule fully for varicella vaccine for all age groups and for the recommended use of Zostavax, the herpes zoster vaccine.
Varivax is currently available in adequate supply, according to Merck, but customers should expect shipping delays of up to 15–20 business days. The company expects to return to normal delivery schedules in late September or early October, but in the meantime two additional shipping days have been added and at least one order per office is being shipped—instead of the normal first-in, first-out model—to minimize the impact on customers with no supply of Varivax.
Production delays also have plagued Merck in manufacturing its pediatric and adult hepatitis A vaccine (Pediatric and Adult Vaqta). It said orders that it received early- to mid-September will continue to be filled on a 6- to 7-week back order, but orders that are received after mid-September will not be available for shipment until near the end of the first quarter of 2008.