Sunday, May 3, 2015
YOLO COUNTY NEWS
99 CENTS

Study: Combining vaccines boosts polio immunity

By
From page B3 | August 24, 2014 |

WASHINGTON (AP) — New research suggests a one-two punch could help battle polio in some of the world’s most remote and strife-torn regions: Giving a single vaccine shot to children who’ve already swallowed drops of an oral polio vaccine greatly boosted their immunity.

The World Health Organization officials said the combination strategy already is starting to be used in mass vaccination campaigns in some hard-hit areas and is being introduced for routine immunizations in developing countries, too.

“It could play a major role in completing the job of polio eradication once and for all,” said Dr. Hamid Jafari, WHO’s director of polio operations, who led the study published Thursday in the journal Science.

Oral polio vaccine has played a critical role in the nearly three-decade effort to eradicate the paralyzing disease, as health workers have gone house-to-house, to refugee camps and to roadside checkpoints delivering the drops. The number of countries where polio regularly circulates dropped from 125 in 1988 to just three as of last year —Pakistan, Nigeria and Afghanistan.

But with travel, the threat is re-emerging in countries previously free of the highly contagious virus. The WHO in May declared an international public health emergency, citing outbreaks in at least 10 countries. Particularly of concern were Syria, Somalia and Iraq, where violence has complicated efforts to contain new cases.

Which vaccine to use in the eradication push has long been controversial. They each have different strengths. The United States and other wealthy countries have switched back to using only injected polio vaccine, which is made of “inactivated” or killed virus, for routine childhood immunizations after eradicating the disease within their borders. That’s because the oral vaccine contains weakened live virus that children can shed in their stools, which on very rare occasions can trigger a vaccine-caused case of polio.

In developing countries where polio is still a threat, the oral version is cheaper, easier to use and can slow spread of the virus. But a particular type of immunity, intestinal immunity, wanes so that children in high-exposure areas need repeated doses.

Jafari’s team tested whether using both vaccines would protect better than one. The study involved nearly 1,000 children, from babies to 10-year-olds, in northern India in 2011, the last year that country reported a case of polio. The children had previously received oral vaccine. This time, they were randomly assigned to receive either a dose of injected polio vaccine, another oral dose or no booster. Four weeks later they all received what researchers called a “challenge” dose of oral vaccine to see how their bodies shed the weakened live virus.

The shots acted as a better booster for the children’s intestinal immunity than giving them yet more vaccine drops — and those youngsters shed far less virus, key to cutting transmission in an outbreak, Jafari’s team reported.

A similar study in 450 children in southern India last year reached the same conclusion, researchers reported in The Lancet last month.

And last December, Kenya put the strategy to its first real-world test. Health workers used both injected and oral vaccine as they sought to immunize 126,000 young children living in Somali refugee camps and nearby areas who were at risk from a polio outbreak spilling over the Somalia-Kenya border. They reached most of the children, according to a report by the U.S. Centers for Disease Control and Prevention.

Similar campaigns are beginning in northeastern Nigeria and should start soon in Pakistan, said Jafari and Dr. Bruce Aylward, WHO’s assistant director-general for polio.

The injected vaccine is more expensive, Aylward said — about $1 to $1.90 a shot, under specially negotiated prices for low-income countries, compared to about 15 cents a dose for oral vaccine. But he said it was worth the investment if adding the shots wound up eliminating polio in the last infected areas faster.

Using this strategy in these tough-to-reach areas makes sense, said CDC vaccine expert Dr. Steve Cochi.

“We want to take maximum advantage of each contact with a child,” he said. “It’s the start of the last stand for wild polio virus, and we’re trying to hit it with both vaccines.”

At the same time, the WHO has called on low- and middle-income countries that now use only oral polio vaccine to add one dose of the injected version to routine childhood immunizations next year.

————

By Lauran Neergaard, AP medical writer

 

Comments

comments

The Associated Press

  • Recent Posts

  • Enter your email address to subscribe to this newspaper and receive notifications of new articles by email.

  • .

    News

    Breaking barriers: For Prieto, it’s all about hard work

    By Lauren Keene | From Page: A1 | Gallery

     
    Council to hear about drought pricing

    By Dave Ryan | From Page: A1

     
    For the record

    By Enterprise staff | From Page: A2

     
    Peaceful Baltimore demonstrators praise top prosecutor

    By The Associated Press | From Page: A2

    Nigeria: Nearly 300 freed women, children led to safety

    By The Associated Press | From Page: A2

     
    Graveyard thefts land three Woodlanders behind bars

    By Lauren Keene | From Page: A3

    Downtown altercation leads to injuries

    By Anne Ternus-Bellamy | From Page: A3

     
    Woman arrested for brandishing knife on overpass

    By Anne Ternus-Bellamy | From Page: A3

    Yolo DA launches monthly newsletter

    By Enterprise staff | From Page: A3

     
    Can plants talk? UCD prof will answer that question

    By Special to The Enterprise | From Page: A3 | Gallery

    A Scottish setting for local author’s next book

    By Special to The Enterprise | From Page: A3

     
    Indoor Fun Fly comes to Woodland

    By Enterprise staff | From Page: A4

     
    Free beginner yoga class offered

    By Enterprise staff | From Page: A4

    Video discusses surveillance of prostate cancer

    By Special to The Enterprise | From Page: A4

     
    NAMI support group meets May 10

    By Enterprise staff | From Page: A4

    Dr. G featured on the radio

    By Special to The Enterprise | From Page: A4

     
    Fee proposed on rail cars that haul oil, other flammables

    By The Associated Press | From Page: A4 | Gallery

     
    Internships move UCD doctoral students beyond academia

    By Julia Ann Easley | From Page: A5 | Gallery

    Make Mom a warm vanilla sugar scrub

    By Enterprise staff | From Page: A6

     
    The secret to Mother’s Day gifting success: Give time, not stuff

    By Special to The Enterprise | From Page: A6

    Letter book is series of collected missives thanking Mom

    By The Associated Press | From Page: A7

     
    If your mom fancies something fancy, consider a tea party

    By The Associated Press | From Page: A7

    Out of Africa and back to Davis: James Carey will give special presentation

    By Kathy Keatley Garvey | From Page: A9 | Gallery

     
    Big Day of Giving makes philanthropy easy

    By Tanya Perez | From Page: A10 | Gallery

    Tuleyome Tales: How are a snake and a mushroom alike?

    By Special to The Enterprise | From Page: A12 | Gallery

     
    Tuleyome hosts Snow Mountain camping trip

    By Special to The Enterprise | From Page: A12 | Gallery

    .

    Forum

    Please help Baltimore

    By Letters to the Editor | From Page: B4

     
    End of life doesn’t mean life must end

    By Special to The Enterprise | From Page: B4 | Gallery

    Advancing education for California’s former foster youths

    By Special to The Enterprise | From Page: B4

     
    With sincere gratitude

    By Letters to the Editor | From Page: B4

    A wonderful day of service

    By Letters to the Editor | From Page: B4

     
    Eyewitness to the ‘fall’ of Vietnam: It was not a bloodbath

    By Special to The Enterprise | From Page: B5 | Gallery

    He can’t give it up

    By Creators Syndicate | From Page: B6

     
     
    Dangers from prescription pills

    By Special to The Enterprise | From Page: B6

    .

    Sports

     
    Defending champ DHS clinches a baseball playoff berth

    By Enterprise staff | From Page: B1

    UCD softball splits with Titans

    By Enterprise staff | From Page: B1 | Gallery

     
    Trifecta of Devil teams open playoffs Tuesday

    By Evan Ream | From Page: B1 | Gallery

    Sports briefs: DHS boys win to reach lacrosse playoffs

    By Enterprise staff | From Page: B3 | Gallery

     
    Making memories at Aggie Stadium

    By Wayne Tilcock | From Page: B3 | Gallery

    Pro baseball roundup: Hudson pitches Giants past Angels

    By The Associated Press | From Page: B12

     
    UCD roundup: Aggie women speed past Hornets

    By Enterprise staff | From Page: B12 | Gallery

    .

    Features

    .

    Arts

    .

    Business

    Marrone opens new greenhouse

    By Special to The Enterprise | From Page: A8

     
    New firm helps students on path to college

    By Wendy Weitzel | From Page: A8

     
    Yolo County real estate sales

    By Zoe Juanitas | From Page: A8

    Arcadia partners on soybean trait to improve yield

    By Special to The Enterprise | From Page: A8

     
    .

    Obituaries

    .

    Comics

    Comics: Sunday, May 3, 2015

    By Creator | From Page: B8