麻豆传媒

The CDC's Advisory Committee on Immunization Practices (ACIP) on Wednesday unanimously endorsed a group of influenza vaccines thought to provide better protection for older adults, as well as a new pneumococcal vaccine for children, and an additional measles, mumps, and rubella (MMR) vaccine.

'Enhanced' Influenza Vaccines

By a vote of 15-0, ACIP recommended that adults 65 and over preferentially receive a quadrivalent high-dose inactivated vaccine, a quadrivalent recombinant vaccine, or a quadrivalent adjuvanted inactivated vaccine over standard-dose, unadjuvanted inactivated influenza vaccines.

Older adults are at increased risk of severe illness, hospitalization, and death from influenza, but the vaccines are frequently less effective in this population, explained Lisa Grohskopf, MD, of the CDC's influenza division.

Based on current usage of this older population, "approximately 2,000 additional deaths would be prevented with enhanced flu vaccines," Grohskopf noted, with an additional 400 deaths prevented if 100% of adults 65 and older received the higher dose or adjuvanted vaccines.

Prior to Wednesday's meeting, ACIP had expressed no preferential recommendation for any specific vaccine in those 65 and older. Prior to the vote, discussion focused on the need to balance the preferential language with logistical concerns.

"I would rather we said that 'high dose or adjuvanted vaccines should be made available for people over 65,'" said Sarah Long, MD, of Drexel University College of Medicine in Philadelphia. "We want to save those extra 2,000 lives."

Sandra Fryhofer, MD, a liaison representative speaking for the American Medical Association, stressed the need to keep the recommendation around preferred vaccines broad. She said her practice typically orders its vaccines in February for the following season, and if the recommendation were too rigid or narrow, "I fear that we will be denying patients any flu vaccine whatsoever."

Helen "Keipp" Talbot, MD, MPH, head of the ACIP working group who drafted the recommendation, explained the rationale for the exception language was to allow seniors to get a standard flu vaccine if nothing else was available "so that we don't have a missed vaccination opportunity."

New Pneumococcal Vaccine for Kids

Following FDA's approval of Merck's pneumococcal 15-valent conjugate vaccine (PCV15; Vaxneuvance) for the prevention of invasive pneumococcal disease in infants and children , the committee voted 15-0 to support the inclusion of PCV15 as an interchangeable alternative to PCV13 in children, following the currently recommended dosing and schedules: a four-dose series at ages 2, 4, 6, and 12-15 months.

Support for PCV15 came from safety and noninferiority data on antibody responses.

Miwako Kobayashi, MD, MPH, CDC's lead on the pneumococcal vaccines work group, noted that the agency did not put forward a preferential recommendation for PCV15 because of certain uncertainties, including concerns related to potentially higher reactogenicity.

"We don't have clinical efficacy," added Long, who was a member of the work group. "We should not think about a preferential [recommendation] when we have no clinical efficacy."

ACIP also called for the inclusion of sickle cell disease or other hemoglobinopathies, as well as congenital or acquired asplenia, and splenic dysfunction to the list of underlying medical conditions where pneumococcal vaccination is indicated.

Another MMR Option

The committee also voted 15-0 to support GlaxoSmithKline's MMR vaccine (Priorix) based on the current recommended schedules and uses for MMR vaccines.

Elisabeth Krow-Lucal, PhD, MPH, of the CDC's National Center for Immunization and Respiratory Diseases, noted that between 2000 and 2003, shortages of recommended vaccines have included MMRII, the only other available option prior to FDA's approval of Priorix .

Safety for the new vaccine was evaluated in six clinical studies involving over 12,000 participants, including 6,391 children from the U.S., who received at least one dose of the vaccine. Priorix was also shown to be a noninferior option based on immunogenicity data.

"Given the similarities in dosage and vaccine components, evidence from the clinical trials and literature review, the workgroup considers that Priorix and MMRII should be considered fully interchangeable, including all off-label uses, and may be administered in any situation in which a measles, mumps, and rubella containing vaccine is indicated," said Krow-Lucal.

The committee concurred with Krow-Lucal's assessment.

As always, all ACIP recommendations are not considered final until they are published in the Morbidity and Mortality Weekly Report.

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