Anne Schuchat

Effectiveness of 23-valent polysaccharide pneumococcal vaccine on pneumonia in HIV-infected adults in the United States, 1998-2003

Pneumococcal polysaccharide vaccine (PPV-23) has been recommended for HIV-infected adults. We investigated factors that could influence PPV-23 effectiveness against all-cause pneumonia in a longitudinal cohort of 23,255 HIV-infected adults receiving care during 1998--2003. Patients who received PPV-23 had a lower rate of pneumonia (IRR = 0.8; 95% CI: 0.8-0.9) than patients who had never been vaccinated, independent of recent CD4 count, HIV viral load, antiretroviral therapy, and history of pneumonia. However, PPV-23 provided no benefit when patients were vaccinated at HIV viral load > 100,000 copies/ml, irrespective of CD4 count at vaccination. Receipt of PPV-23 was associated with lower incidence of all-cause pneumonia.

Early Experience with Human Papillomavirus Vaccine Introduction in the United States, Canada and Australia

Successful incorporation of a new vaccine into a nations vaccination program requires addressing a number of issues, including: 1) establishing national recommendations; 2) assuring education of and acceptance by the public and medical community; 3) establishing and maintaining an appropriate infrastructure for vaccine delivery; 4) financing the vaccine and the program, in addition to political will. This article reviews the early experience with implementation of human papillomavirus (HPV) vaccination programs. It focuses on the United States of America and Canada and provides a brief report on Australia, where introduction is underway.

Multistate Evaluation of Invasive Pneumococcal Diseases in Adults with Human Immunodeficiency Virus Infection: Serotype and Antimicrobial Resistance Patterns in the United States

Persons with acquired immunodeficiency syndrome (AIDS) have a higher incidence of invasive pneumococcal disease (IPD) than other adults, and many receive long-term trimethoprim-sulfamethoxazole (TMP-SMZ) prophylactic therapy. We used 1998-1999 data from the Active Bacterial Core surveillance of the Emerging Infections Program Network to compare IPD infections between adults aged 18-64 years with human immunodeficiency virus (HIV) infection and other adults. Of 2346 patients with IPD, 416 (18%) had HIV or AIDS (HIV/AIDS). Certain serotypes (serotypes 6A, 6B, 9N, 9V, 18C, 19A, 19F, and 23F) were more common among patients with HIV/AIDS than in adults with no underlying disease (P<.05, vs. serotype 4), even when TMP-SMZ-nonsusceptible isolates were excluded. HIV/AIDS (adjusted odds ratio [aOR], 1.93; 95% confidence interval [CI], 1.44-2.59), immunocompromising conditions other than HIV/AIDS (aOR, 1.56; 95% CI, 1.12-2.18), and black race (aOR, 1.50; 95% CI, 1.20-1.88) were independent risk factors for infection with these serotypes. HIV/AIDS was not an independent risk factor for TMP-SMZ nonsusceptibility. Vulnerability to certain serotypes among adults with HIV/AIDS may have implications in prevention strategies.

Monitoring the impact of vaccines postlicensure: new challenges, new opportunities

Although vaccines are studied intensively before licensure, insight into important aspects of vaccine performance and the effectiveness of immunization programs and policies can only be detected after vaccines enter widespread use. Now that 17 diseases are targeted for prevention through routine immunizations in the USA, reassessment of the nation’s vaccine-preventable disease-monitoring efforts is appropriate. Postlicensure disease monitoring has permitted recognition of indirect protection, vaccine effectiveness of various schedules, duration of protection, health disparities, importation patterns and microbial adaptation. The investments in vaccine research, development and regulatory procedures prelicensure, as well as resources devoted to purchase, distribution and delivery of vaccines after introduction, necessitate strategic efforts to monitor the impact of large-scale use of vaccines on disease over time.

Protecting Adults From Influenza: Tis the Season to Learn From the Pandemic

influenza vaccination of older adults, pregnant women, and others with chronic medical conditions [2]. Vaccination rates among the elderly increased substantially during the 1990s [3] but subsequently plateaued at approximately 60% to 70%. Older adults continue to experience a disproportionate burden of severe illness caused by influenza. Unfortunately, influenza vaccine effectiveness is generally lower among older populations, even during seasons when vaccine strains are well matched to circulating viruses. Efforts to overcome immune senescence and identify formulations with improved immunogenicity and clinical protection have been a focus of researchers, manufacturers, and the government. The potential roles of highdose antigen formulations as well as adjuvants in improving immune response have been of particular interest with respect to both avian and seasonal influenza vaccines. Jackson investigated effects of dose, adjuvant, and age on the immunogenicity of pandemic vaccine [1]. Of note, the study used antigen from 1 manufacturer extemporaneously mixed with an oil-inwater emulsion adjuvant of another, mimicking a potential real-life need to expand vaccine coverage during a pandemic. The immunogenicity of 2 doses of 3.5, 7.5, and 15 μg of split inactivated 2009 H1N1 vaccine with AS03 adjuvant or 7.5 and 15 μg without adjuvant was assessed in adults aged 18–64 and ≥65 years. Confirming the results of earlier 2009 H1N1 vaccine studies, a single dose of unadjuvanted vaccine at either standard (15 µg) or half (7.5 µg) dose induced serum hemagglutination-inhibition (HI) antibody responses in the majority of adults in either age group, although a greater proportion of older adults receiving the standard dose achieved HI titers of ≥40 [4–6]. Rising HI antibody titers were evident as early as 8 days after a single dose of either unadjuvanted or adjuvanted vaccine, consistent with other reports [7]. Adjuvanted vaccine elicited more robust responses in adults aged ≥65 years compared with the standard dose of unadjuvanted vaccine, and a second dose of adjuvanted vaccine boosted titers in seniors as well as in younger adults, with a notable increase in the durability of the response at 6 months. Significantly lower responses were detected within each vaccine group in those aged 36–50 and 51–64 years compared with the youngest group aged 18–35 years.

Measles in the United States since the Millennium: Perils and Progress in the Postelimination Era.

This article describes measles and measles vaccination, along with the challenges, successes, and progress in the postelimination era.