Merck & Co. has issued an update on the status of its vaccine delays and shortages in a letter to physicians.
Merck 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. In the letter, the company said that it was too early to determine 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.
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 (Thursday for Friday delivery and Saturday for Monday delivery) 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). A manufacturing change that is under regulatory review started the delays, which have caused customers to experience 6- to 7-week shipment delays since late July 2007. The company said that orders for the vaccine that it received through 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.
The supply of GlaxoSmithKline's pediatric and adult hepatitis A vaccine (Pediatric and Adult Havrix) is adequate enough to meet demand; GSK has initiated plans to produce more Havrix to help ensure uninterrupted supply for the U.S. market, according to the CDC.