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The CDC's vaccine advisors updated their recommendations to clarify when to administer the 20-valent conjugate pneumococcal vaccine (PCV20; Prevnar 20) in adults who previously received the 13-valent conjugate vaccine (PCV13; Prevnar 13).

In adults 65 and up who have completed their vaccine series with both the PCV13 and 23-valent polysaccharide vaccine (PPSV23; Pneumovax 23), the Advisory Committee on Immunization Practices (ACIP) voted 13-2 to recommend shared decision-making to determine whether to give PCV20 at least 5 years after their last dose of pneumococcal vaccine.

For those under 65 with certain underlying conditions or risk factors who have received both the PCV13 and PPSV23 vaccines but have not completed their full vaccine schedule, ACIP voted 14-1 to recommend one dose of PCV20 at least 5 years after their last dose, or otherwise PPSV23 as previously recommended, to complete their vaccine series.

Finally, for individuals who previously received the PCV13 vaccine only, the committee voted unanimously to recommend a dose of PCV20 at least 1 year later, or otherwise PPSV23 as previously recommended, to complete their vaccine series.

Last year, ACIP streamlined its recommendations for pneumococcal vaccine in adults who have not yet received a conjugate vaccine: all older adults, as well as younger adults with certain underlying medical conditions or risk factors, should receive one dose of PCV20, or otherwise the 15-valent conjugate vaccine (PCV15; Vaxneuvance) followed by PPSV23.

With Thursday's new recommendations, the committee addressed the use of PCV20 in adults with a vaccine history that includes PCV13.

Miwako Kobayashi, MD, MPH, the ACIP work group lead for pneumococcal vaccines, explained that conjugate vaccines are expected to have a longer duration of protection than polysaccharide vaccines. In addition, she noted in her presentation, "limited effectiveness of PPSV23 has been reported in adults with immunocompromising conditions."

Adults 65 and Older

Not all ACIP members were on board with the shared decision-making aspect of the new recommendation for adults 65 and older, with Helen "Keipp" Talbot, MD, of Vanderbilt University in Nashville, arguing the language be dropped in favor of a full recommendation. An amendment for a full recommendation failed to garner enough votes (6 for, 9 against), with cost considerations weighing on some members.

Cost-effectiveness estimates from CDC suggested a range of $153,000 to $414,000 per quality-adjusted life year with a full recommendation, which would apply to about 17 million older adults, Kobayashi said.

ACIP member Beth Bell, MD, MPH, of the University of Washington in Seattle, said that while she is sympathetic to wanting to save as many lives as possible, it is still important to consider the costs.

"I don't feel like it's a good idea to endorse something which involves ... essentially re-vaccinating a very large number of people for a very small incremental benefit," said Bell.

"It's a huge benefit," countered Talbot.

"Many older adults are still working," she continued. "Some of them are at the table with us, and we would like to keep them working because they have brilliant minds and should be able to continue to contribute."

Oliver Brooks, MD, of Watts HealthCare in Los Angeles, said he found the "compelling," but noted that rates of pneumococcal disease are higher in African Americans with serotypes that aren't covered by PCV13, and suggested that shared decision-making was unlikely to benefit this group.

Younger Adults With Underlying Conditions

A sticking point for some committee members was the 5-year wait to administer PCV20 in younger adults (19 to 64) with certain underlying conditions or risk factors -- such as immunocompromising conditions, cochlear implants, or cerebrospinal fluid leaks -- who have received both PCV13 and PPSV23 but have yet to complete their full vaccine series.

Talbot argued for recommending the PCV20 dose 1 year later, noting that the effectiveness of polysaccharide vaccines wanes quickly. Efficacy suggested a decline with PPSV23 as early as 2 years, while no decline had been observed in the first 5 years with a conjugate vaccine.

ACIP member Camille Kotton, MD, of Massachusetts General Hospital in Boston, agreed, noting that 3% of the U.S. population is immunocompromised and pointing out that this group has up to an 18 times higher risk for invasive pneumococcal disease.

However, Sarah Long, MD, of St. Christopher's Hospital for Children in Philadelphia, said the working group determined that a conjugate vaccine together with PPSV23 allowed recipients to be "pretty well protected for 5 years," and giving another dose so soon after the previous one would add "very little" benefit.

An amendment to recommend a 1-year wait before a PCV20 dose in this population failed to pass by a vote of 2-13.

All recommendations from ACIP are not considered final until they are published in the Morbidity and Mortality Weekly Report.

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