PHILADELPHIA — Administering two or more vaccines simultaneously was safe and immunogenic in results from two separate studies reported at the annual meeting of the Infectious Diseases Society of America.
One study assessed the immune response when healthy girls received concomitant vaccination with a human papillomavirus (HPV) vaccine along with a vaccine for tetanus, diphtheria, and pertussis (Tdap), and a third vaccine with a quadrivalent, conjugated meningococcal formulation (MCV4). The second study tested coadministration of the 2007–2008 seasonal influenza vaccine with an investigational, 13-valent, conjugated pneumococcal vaccine in adults aged 50–59 years.
The results from combined administration of the HPV, Tdap, and meningococcal vaccines are especially relevant to practice because all three are already approved for U.S. use, and the concept of delivering all three simultaneously received endorsement by the Centers for Disease Control and Prevention's Advisory Committee on Immunization Practices in 2007 (MMWR 2007;56:1-24). The only piece missing until now was data showing that the concomitant strategy was safe and immunogenic—something the new study now provides, said Cosette M. Wheeler, Ph.D., professor of pathology and obstetrics and gynecology at the University of New Mexico in Albuquerque.
All three vaccines are recommended for administration to adolescent girls, and bundling them together at one time would potentially increase compliance, Dr. Wheeler said in an interview (although the HPV vaccine requires three doses administered over a 6-month period).
Her study used the Cervarix formulation of HPV vaccine, the Boostrix formulation of Tdap, and the Menactra formulation of meningococcal vaccine. The Cervarix and Boostrix vaccines are marketed by GlaxoSmithKline, which funded the study. Menactra is marketed by Sanofi Pasteur. Dr. Wheeler disclosed that in addition to receiving research support from GlaxoSmithKline, she also received funding for studies from Merck, which markets the HPV vaccine Gardasil, and from Roche Molecular Systems.
The study enrolled 1,283 healthy girls aged 11–18 years at 48 U.S. centers. The researchers randomized the participants to one of six different treatment schemes: HPV vaccine only at months 0, 1, and 6; HPV with Tdap at month 0 followed by HPV only at months 1 and 6; HPV with the meningococcal vaccine at month 0 followed by HPV only at months 1 and 6; all three vaccines at month 0 followed by HPV only at months 1 and 6; Tdap only at month 0 followed by HPV only at months 1, 2, and 7; and MCV4 only at month 0 and then HPV only at months 1, 2, and 7.
The results showed that 1 month after the subjects received any of the concomitant doses, their immune responses all fell within the prespecified criteria for noninferiority, compared with the responses when the vaccines were administered individually. Also, the immune responses to the HPV vaccine 6 months after the final dose, when one dose was given in combination with one or two of the other vaccines, were noninferior to the responses to the HPV vaccine given by itself. The recipients of two or more simultaneous vaccines also had similar incidence rates for solicited local reactions—pain, redness, or swelling, and similar solicited rates of system reactions, including headache, fatigue, and myalgia.
The second study examined concomitant administration of an investigational, 13-valent, conjugated pneumococcal vaccine and the trivalent, seasonal influenza vaccine of 2007–2008 in 1,106 healthy adults aged 50–59 years. The pneumococcal vaccine is similar to a 7-valent vaccine that already has U.S. approval for use in infants and children, Prevnar, with added antigens so that the vaccine protects against strains that commonly cause community-acquired pneumonia, said Dr. Robert W. Frenck Jr., of Cincinnati Children's Hospital Medical Center.
The pneumococcal vaccine was developed by Wyeth (which recently was acquired by Pfizer Inc.), which funded the study. Dr. Frenck had no other disclosures for his study.
One month after vaccination, the immune responses to both vaccines in people who received them simultaneously fell within the prespecified noninferiority limit, compared with the responses in people who received the two vaccines 1 month apart. Simultaneous administration also resulted in similar rates of local and systemic reactions compared with giving the vaccines 1 month apart.