Vaccinations and Older Adults

Debra L. Bynum, MDFebruary 19, 2004

Questions to ponder…

Should we more aggressively target older patients admitted to the hospital for influenza and pneumococcal vaccinations during their inpatient stay?

Is there any evidence that pneumococcal vaccinations in the elderly prevent hospitalizations or death from pneumonia?

Is there an association between influenza vaccination and a decreased risk of CVD events?

What is the role of vaccinating the healthy young population against influenza in preventing influenza related illnesses and deaths among the elderly?

What are the recommendations regarding tetanus, MMR and varicella immunizations for older adults?

Overview

Influenza vaccine: evidence and recommendations for older adults

New focuses on reducing risk of influenza related complications in older adults: vaccinating children, health care workers and hospitalized elders

Pneumococcal vaccine in older adults: controversies regarding effectiveness

Tetanus boosters ?Varicella

Influenza

36,000 deaths,114,000 hospitalizations/year Rates of infection highest among children,

rates of serious illness and death highest among those over 65

Older adults account for over 90% of deaths attributed to pneumonia and influenza

Seasons with dominant influenza A viruses are associated with higher mortality

Recommendations of the Advisory Committee on Immunization Practice: The “Who”

All over 65 All ages 50-64 with illnesses such as diabetes, renal

disease, other immunocompromised states ?all aged 50-64 (1/3 have chronic medical

conditions) Health care workers/workers at hospitals/long term

care facilities People who live with high risk patients

Allergies…

Vaccine viruses are initially grown in embryonated hens’ eggs so slight risk that vaccine might contain limited amounts of residual egg protein

Efficacy of influenza vaccine

70-90% in healthy young adults Cochrane review: overall vaccine 65% in preventing

serologically confirmed cases and 72% effective when there was good match between the antigen in the vaccine and the dominant circulating virus (each year vaccine designed to target specific potential strains)

Overall those vaccinated in studies have 1/3 less acute URI illnesses, less absenteeism

Efficacy in older adults

Factors: age and immunocompetence of recipient and degree of similarity between viruses in vaccine and those in community

Concern that older or immunocompromised patients develop lower hemagglutination inhibition ab titers

Efficacy in older adults

RCT with community dwelling people over age 60 found efficacy of 58%, but indicated might be lower among those over 70

Among community dwelling older adults, vaccine 30-70% effective in preventing hospitalization for pneumonia and influenza

Nursing home residents: most effective in preventing severe illness, secondary complications and deaths; Although only 30-40% effective for preventing influenza illness, 50-60% effective in preventing hospitalization or pneumonia and 80% effective for preventing death

When to start?

Risk based recommendations for vaccination in the under 65 age group less successfully implemented

National data indicate that 65% of those over 65 get vaccinated, but only 30-40% under 65 who are at high risk get vaccinated

CDC, ACIP, AAFP now recommend all adults begin receiving annual influenza immunization at age 50!

New Focus: Prevent Influenza related deaths in older adults by preventing transmission

Shift from only vaccinating high risk (they are usually at end of the “transmission chain”) as immunization of this group alone will not alter the course of an epidemic

Alternative strategy: direct vaccination toward healthy children and adults in the community who are key disseminators

School age children as main introducers of influenza into households (children more frequently acquire and shed virus than adults)

Clinical studies looking at targeting school age children have shown decreased rates of illness in ALL age groups

Importance of Vaccinating Health Care Workers

Two RCTs have studied vaccination of HCWs on mortality of elderly in LTC facilities

Targeted facilities had significantly lower total patient mortality and influenzalike illness among residents

Mortality 13.6 % in facilities with higher HCW immunization rates vs 22.4% in control facilities

Live Attenuated Influenza Vaccine– Any Role for the elderly?

Nasal vaccine LAIV replicates in mucosa of nasopharynx to induce

protective immunity, but replicate inefficiently in the warmer temperatures of the lower respiratory tract

Efficacy in children and young adults equal to that of the current vaccine (ages 5-49)

Theoretical transmission risk, therefore not recommended for HCWs, close contacts, or elderly or immunocompromised

Other benefits?

Reduction in hospitalization for cardiac disease and stroke among the elderly

Observation that hospitalizations for stroke and cvd increase among the elderly during influenza epidemics

Two large cohorts of community dwelling older adults followed

Influenza vaccine and reduction in CVD and Stroke?

Outcome Vaccinated Unvaccinated

Admitted flu/pneumonia 495 (0.6%) 581 (0.9%)

Admitted CVD 888 (1.1%) 1026 (1.6)

Admitted CHF 466 (0.6%) 538 (0.9)

Admitted cerebrovasc dz

398 (0.5) 427 (0.7)

Deaths 943 (1.2) 1361 (2.2)

Hosp/death 2387 (3.1) 2910 (4.7)

Vaccine and CVD…

ARR hospitalization for pneumonia or influenza 0.3%, NNT 333 (RR 33%)

ARR hospitalization or death 1.6%, NNT 62.5 Limitations: observational study, ?differences not

accounted for in those who did not receive vaccine?? Baseline: more patients in vaccinated group had

CVD and other comorbidities; more in unvaccinated group had dx of dementia or stroke

Getting older adults vaccinated

What affects influenza immunization rates among older adults?: Physicians and Perceptions

– VA study: 100% vaccinated patients reported that their MDs had recommended it vs 63% of unvaccinated patients

– 38% unvaccinated patients vs 6% vaccinated patients were concerned they would get the flu from the vaccine

Am J Med Jan 2003

Getting people vaccinated

Influenza vaccination levels among those over 65 have increased from 33% in 1989 to 66% in 1999

Evidence that standing orders and systems changes most effective

Importance of acute care setting: any person over age 50 admitted during sept-march should receive vaccine

– 39-46% patients hospitalized with influenza related diagnoses had been hospitalized during the preceding fall

– Only 31% of medicare patients in one study vaccinated before admission, 1.9% during admission

Influenza Vaccination: Summary

Decreases risk of overall mortality, hospitalizations, all cause pneumonia in older patients

? Association with decreased risk of CV events We can increase rates of vaccination by

recommending the vaccine and providing standing orders and systems changes

We can immunize in the hospital: Over 1/3 of patients over age 50 admitted with influenza related illnesses had been admitted the preceding fall!

Pneumococcal vaccines…

Concern with pneumococcal bacteria: leading cause of pneumonia and tendency to lead to infections of the bloodstream and death

Annual incidence of pneumococcal bacteremia: – People over age 65: 50-83 cases/100,000– General populaiton: 15-30 cases/100,000– Case fatality rate for pneumococcal bacteremia among

older adults: 30-40%

History of the pneumococcal vaccine

First released in 1940s, but withdrawn when pcn and sulfonamide drugs came along

Relicensed in 1977 (14 valent polysaccharide vaccine; replaced by 23 valent vaccine 1980)

6 pneumococcal serotypes that most commonly cause invasive drug resistant disease in US are included in vaccine

Over 95% of multidrug resistant invasive strains involve 5 serotypes that are included

History of the pneumococcal vaccine…

Original studies demonstrating significant efficacy done in health young adults (South African gold miners and New Guinea highlanders)

Current recommndations

Over age 65 ?over age 50 (1/3 have chronic diseases, and may

maximize immune response); recommended by ACP and ACIP

Reimmunization: one time second dose for adults who received their first dose before age 65 and are at least 5 years out from first

Reimmunization recommended for adults who received first dose at age 65 or older and over 5 years out if they are at high risk for serious infection (splenectomy, renal failure, HIV, lymphoma, MM, leukemia, immunosuppression)

Efficacy of the pneumococcal vaccine

Several clinical studies, including large VA study, have failed to demonstrate efficacy in preventing pneumococcal pneumonia, any cause pneumonia, hospitalizations or mortality in high risk elderly

23 valent vaccine covers 23 of the known 90 serotypes (85% of serotypes most commonly cultured)

Efficacy depends upon what outcome is studied (prevention of bacteremia/invasive disease vs overall mortality or pneumonia or hospitalization)

Efficacy of the pneumococcal vaccine

Observational studies consistently demonstrate effectiveness of 50% at preventing pneumococcal bacteremia among older adults

Retrospective study of over 47,000 people over age 65

– Vaccine was associated with decrease in bacteremia (HR .56); n = 61/47,000 (small number: 50% reduction of 50/100,000 or .05% risk is only .025% risk)

– No difference in hospitalizations, pneumonia, or death

Pneumococcal Vaccine: Summary

Evidence lacking to show overall benefit in decreasing mortality, hospitalizations or pneumonia from pneumococcus or all cause pneumonia

Very small reduction in risk of pneumococcal bacteremia: numbers too small to translate into significant numbers in studies

Safe, easy, inexpensive and may be of small individual benefit in at risk older individuals so current recommendations still include

Other immunizations for older adults

Tetanus and diphtheria (Td)– Administer one dose if received primary series

and last vaccination was 10 years ago or longer– Administer 3 dose primary series if not received

(not uncommon for elderly in US)– ACP task force second option: singe Td booster

at age 50 for those who completed primary series including teenage/young adult booster

Varicella

Over 95% of older adults have been exposed to varicella

Recommended for those at risk with no documented exposure

Studies looking into whether or not vaccine can prevent or attenuate zoster in older adults