Landmark Developments in Infectious Diseases

A 20-Year Look-Back: Two Steps Forward, One Step Back

Ingrid G. Hein


October 20, 2015

In This Article

Vaccines and Vaccine-Preventable Illnesses

It has been a landmark time for vaccine recommendations and programs. The CDC, American Academy of Pediatrics, and American Academy of Family Physicians have endorsed annual childhood immunization schedules since 1996.

"Vaccines have shifted mortality rates substantially in the past 20 years, and we have had much better vaccine adherence," Stephen Calderwood says. "We have also had vaccine hesitancy, affecting measles and pertussis."


In 2014, the United States experienced a record number of measles cases (668 cases from 27 states), a disease that had been reportedly eliminated in 2000.[23] The multistate measles outbreak in 2014-2015 was said to have originated from an overseas visitor to California's Disneyland theme park. CDC analysis of the measles virus showed that it was the same virus that caused the Philippines outbreak in 2014.[24]

"People think of measles as a fever and a rash and you recover, but mortality can be in the range of 0.3%-0.5%, and in developing countries it's 1%-4%." Calderwood says. "We have been lulled into a sense that these illnesses are not life-threatening, and we don't need to worry. That's not the case."


The rotavirus vaccine was introduced in the United States in 2006, and has been credited with preventing 40,000-50,000 hospitalizations of infants and children. Before the vaccine was available, rotavirus infection resulted in severe diarrhea and dehydration, and 20-60 deaths in children younger than 5 years in the United States each year. Worldwide, rotavirus infection caused an estimated 453,000 childhood deaths before vaccines were introduced and recommended by the WHO.[25]

"These are serious diseases, not just nuisances." Calderwood says. "They cause death, a lot of morbidity, and unnecessary healthcare costs.

Meningococcal Disease

Starting in 2010, the meningococcal A conjugate vaccine was rolled out to the region of sub-Saharan Africa known as the "meningitis belt," which includes countries from Senegal in the west to Ethiopia in the east. In 2013, outbreaks of serogroup B meningococcal disease on two US college campuses led to the approval of new vaccines for persons aged 10-25 years.[26] In 2015, these new vaccines were given a "permissive" recommendation, meaning that they are not routinely recommended.

Human Papillomavirus

In 2006, the Advisory Committee on Immunization Practices (ACIP) made its first recommendation for human papillomavirus (HPV) 4 vaccine in women aged 9-26 years, protecting against an infection known to cause 100% of cervical cancers, along with oral, anal, vulvar, vaginal, and penile cancers and genital warts.[27]

By 2013, more than one third (37.6%) of adolescent girls aged 13-17 years had completed the three-dose vaccine series in the United States. The prevalence of HPV declined significantly between 2003 and 2010, from 11.5% to 5.1% among girls aged 14-19 years.[28] As of December 2014, a new HPV vaccine (Gardasil® 9) became available, which protects against HPV types 6, 11, 16 and 18 (covered in the previous vaccine) plus five additional high-risk strains: 31, 33, 45, 52, and 58.[29]


Perhaps the most widespread vaccine programs have been those aimed at dissemination of the annual influenza vaccines. On February 24, 2010, the ACIP voted for universal flu vaccination in the United States, which expanded protection against the flu to more people. Everyone aged 6 months or older should receive the flu vaccine every season, particularly those at high risk (aged ≥ 65 years, pregnant women, and persons with certain chronic medical conditions).

Major diseases for which vaccines remain elusive, however, include malaria, Ebola, and HIV.


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