Top stories for World Immunization Week

World Immunization Week is acknowledged annually from April 24-30 to raise awareness of the importance of child and adult immunizations. In recognition of this year’s theme, “Close the Immunization Gap,” WHO has released data on progress made toward global immunization and what challenges remain in meeting the worldwide eradication of vaccine-preventable diseases by 2020.

“Major breakthroughs” in immunization that occurred last year include the elimination of maternal and neonatal tetanus in India, the elimination of rubella in the Americas, widespread immunization against meningitis A disease in the African “meningitis belt,” and the development of new vaccines against dengue, Ebola and malaria, according to the release. WHO also noted the global switch from the trivalent oral polio vaccine to the bivalent oral polio vaccine, as well as the removal of Nigeria from the list of polio-endemic countries. The agency reported that only Afghanistan and Pakistan remain polio endemic.

“Last year, immunization led to some notable wins in the fight against polio, rubella and maternal and neonatal tetanus,” WHO Director-General Margaret Chan, MD, said in the release. “But they were isolated wins. Polio was eliminated in one country, tetanus in three, and rubella in one geographical region. The challenge now is to make gains like this the norm.”

Margaret Chan

In 2012, the World Health Assembly approved the Global Vaccine Action Plan , which aims to eliminate vaccine-preventable diseases by 2020. However, only one of s ix midterm targets is on track: the introduction of at least one new or underutilized vaccine in at least 90 low- and middle-income countries by 2015. According to WHO, 86 countries have made 128 vaccine introductions. Other unmet targets include 90% national coverage against diphtheria, tetanus and whooping cough; the global eradication of polio; elimination of maternal and neonatal tetanus in 59 priority countries; the eradication of measles from four WHO regions; and the eradication o f rubella from two WHO regions.

“Although the world has seen some achievements in immunization, global vaccination coverage has stalled the past few years ,” Flavia Bustreo, MD, MSc, assistant director-general for WHO’s Family, Women and Children’s Health and vice chair of Gavi, the Vaccine Alliance Board, said in the release. “Far too many opportunities to reach unvaccinated children and close the immunization gap are still being missed every day.”

Flavia Bustreo

WHO estimated that 18.7 million infants — nearly one in five children — are lacking routine immunizations for preventable diseases, which are responsible for approximately 1.5 mill ion deaths worldwide each year. According to the release, recent field assessments in the Americas and Africa demonstrated that up to 96% of children who visited a health care facility did not receive the vaccines they needed.

“These children are not what we would consider ‘hard-to - reach’ or underserved populations,” Jean-Marie Okwo-Bele, MD, MPH, director of WHO’s immunization for vaccines and biologicals department, said in the release. “Children who are already present in health facilities are easy wins in improving vaccination coverage.”

Jean-Marie Okwo-Bele

The Strategic Advisory Group of Experts on Immunization identified five factors that could improve immunization coverage, including the quality and use of data; community involvement; broader access to immunization services; stronger health care systems; and increased access to vaccines. The cost of vaccines, however, remain a barrier.

Earlier this year, the CDC marked the 50th anniversary of the establishment of its smallpox eradication program. WHO declared smallpox eradicated in 1980, 3 years after the last natural case was documented — a major accomplishment in global immunization.

According to Eric E. Mast, MD, MPH, deputy director for science and program for the Global Immunization Division in the CDC’s Center for Global Health, the world is “on the cusp” of eradicating polio with measures that have been in place since 1988.

Eric E. Mast

“It would be on the level of smallpox eradication when it’s achieved,” Mast told Infectious Disease News.

Beyond the eradication of smallpox and the progress toward eradicating polio, Mast said other accomplishments in the past 50 years of immunization include a worldwide decline in measles deaths; the introduction since 2000 of vaccines for hepatitis B virus, haemophilus influenza, rotavirus and pneumococcal disease; and the elimination of measles and rubella in the Western Hemisphere.

“Going forward, we’d like to see globally building on and leveraging the achievement of polio eradication to do three main things,” Mast said. “One is to achieve a world free of measles and rubella. A second thing is ending vaccine-preventable disease deaths in children. We see that being accomplished to a large part by linking measles elimination to improving immunization programs and improving vaccine coverage. A third one is reducing deaths from cancers that can be prevented by vaccines. Those include hepatitis B, which causes liver cancer, and human papillomavirus, which causes cervical cancer.”

To mark the occasion of World Immunization Week, Infectious Disease News has compiled a list of the top 10 stories about vaccine-preventable diseases in 2016. – by Stephanie Viguers and Gerard Gallagher

ACIP publishes updated immunization schedule for adults

The Advisory Committee on Immunization Practices has published its 2016 immunization schedule for adults aged 19 years and older in the Annals of Internal Medicine. The revised schedule includes changes to pneumococcal, meningococcal and HPV vaccinations, which reflect recommendations from the ACIP. Read more.

ACIP publishes updated 2016 vaccine recommendations for children, teens

The CDC has published its 2016 immunization schedule guidelines for children and adolescents aged 18 years and younger, including the addition of a “permissive recommendation” for serogroup B meningococcal vaccine and the addition of a “blue bar” signifying its status as a category B recommendation. Read more.

World marks switchover to bivalent oral polio vaccine

Between April 17 and May 1, 155 countries and territories around the world will stop using the trivalent oral polio vaccine and begin using a bivalent oral polio vaccine in what WHO has called the largest vaccine rollout in history. The vaccine switchover is the first stage of a larger plan to withdraw all OPVs. Read more.

H1N1 dominates mild 2015-2016 flu season

The 2015-2016 influenza season has been milder than the previous three seasons and appears to have peaked later than normal, according to the CDC.

“It looks like March will have been the peak for this season,” Lynnette Brammer, MPH, epidemiologist for the CDC’s domestic influenza surveillance team, told Infectious Disease News. Read more.

Intentional vaccine avoidance causes most measles cases

The majority of measles and pertussis cases during outbreaks with comprehensive vaccine data were a result of intentional vaccine refusal, according to recent research in JAMA. Of the eight outbreaks with detailed data, the proportion of intentionally unvaccinated patients ranged from 59% to 93%. Read more.

Single-dose live oral cholera vaccine safely reduces diarrhea

A single-dose live cholera vaccine taken orally appeared to reduce the incidence of diarrhea among adults with no increase in adverse events, according to a recently published study.

PXVX0200 is a reformulation of CVD 103-HgR — a live-attenuated cholera vaccine that was commercially available outside of the United States from 1994 to 2004. Acquired in 2009 by PaxVax, the newer vaccine has since demonstrated early results similar to those reported during trials of its predecessor. Read more.

California vaccine compliance increased ahead of SB 277 enactment

The kindergarten vaccination rate has increased in California, ahead of the July 1 effective date of Senate Bill 277, which will eliminate all nonmedical vaccine exemptions throughout the state, according to recent data published by the State of California. Read more.

Most clinicians do not mention HPV, HBV vaccines as reducing cancer

Only 7% of clinicians recommended to patients that the HPV and hepatitis B vaccines specifically can reduce cancer, according to a recent survey. Read more.

Timely DTaP vaccination could reduce infant pertussis, hospitalizations

Timely DTaP vaccination among newborn infants could reduce cases of pertussis-related hospitalization and death, according to research in the Pediatric Infectious Disease Journal. Timely vaccinations also would result in significant annual health care-related cost savings. Read more.

Dengue vaccine shows full protection in human challenge model

A dengue vaccine currently in phase 3 development was 100% effective at preventing the disease, according to the results of a small clinical trial in which volunteers were inoculated and then given a weakened dose of the most difficult dengue virus serotype to prevent 6 months later. Read more.