Newer whooping cough vaccine safer, but not as effective

The pertussis vaccine is given in combination with vaccines for diphtheria and tetanus.
The pertussis vaccine is given in combination with vaccines for diphtheria and tetanus.

A newer version of the whooping cough vaccine doesn’t protect kids as well as the original, which was phased out in the 1990s because of safety concerns, according to a new study.

During a 2010-2011 outbreak of whooping cough in California, researchers found that youth who had been vaccinated with the newer, so-called acellular, vaccine were six times more likely to catch whooping cough than those who had received a series of the older whole-cell vaccine.

“This is an ongoing saga,” said Dr. H. Cody Meissner, a pediatric infectious diseases specialist from Tufts University School of Medicine in Boston.

The rate of whooping cough, or pertussis, has been climbing in recent years, he said — to the point where “we’re worried about losing control of pertussis in the United States.”

The pertussis vaccine is given in combination with vaccines for diphtheria and tetanus.

Originally the shot contained whole pertussis bacteria, which triggered reactions in some babies — including prolonged crying, fever and a “shock-like state,” said Meissner, who wasn’t involved in the new research.

So in the 1990s, the U.S. switched over to an acellular version of the vaccine, which has reduced the rate of side effects.

“But the price we’ve paid to get more safety is that we have less effectiveness,” Meissner told Reuters Health. “It doesn’t protect as well against pertussis.”

The U.S. Centers for Disease Control and Prevention recommends four doses of the diphtheria, tetanus and pertussis vaccine (DTaP) be given to babies between two and 18 months, and a fifth dose by age six. A booster was recently added to the vaccine schedule for 11- to 12-year-olds.

For the new study, researchers from the Kaiser Permanente Northern California health system compared the vaccination history of 138 teenagers and preteens who tested positive for whooping cough and about 55,000 who did not during the state’s 2010-2011 outbreak.

Over the course of the outbreak, 78 out of every 100,000 adolescents were infected per year.

Almost all of the kids had received the newer acellular vaccine as their fifth DTaP dose. But Dr. Nicola Klein and her colleagues found that teens who’d been vaccinated with the acellular version for each of their first four doses as well were six times more likely to contract whooping cough than those who’d received four doses of the whole-cell vaccine.

Each extra acellular rather than whole-cell dose increased a child’s risk of later developing whooping cough by about 40 percent, the researchers reported Monday in Pediatrics.

Klein said there seem to be some differences in the initial immune response to the whole-cell vaccine versus the acellular vaccine, which may persist as children get older. Her team’s study, she said, suggests there needs to be more of a focus on developing a third pertussis vaccine.

But any new shot for whooping cough that could address both safety and effectiveness concerns is still years away, Meissner said.

“So now we’re confronted with this difficult problem,” he said.

“It’s very hard to recommend a vaccine that is known to be associated with more side effects than another vaccine that’s safer, even though the first vaccine gives better protection. It’s a dilemma.”

The findings do not mean parents shouldn’t get their children fully vaccinated against pertussis, the researchers agreed.

“In the short run, we have to keep vaccinating kids on the recommended schedule because that’s definitely the best way to protect kids,” Klein told Reuters Health.

“The acellular vaccine does work, it just doesn’t last as long as we hoped,” she said. “It’s the best tool we have right now to protect against pertussis.”



News
Entertainment
Sports
Lifestyle
International

Hurricane Odile batters Mexico's Baja resorts, sparks looting

Hurricane Odile injured dozens of people, forced the evacuation of thousands and smashed shops open to looters in the popular tourist area of Baja, Mexico.

National

Apple iPhone 6 pre-orders hit record 4 million…

By Lehar Maan(Reuters) - Apple Inc said many customers will need to wait until next month for their new iPhones after a record 4 million…

National

LAPD investigates complaint from detained 'Django' actress

The LAPD is investigating after "Django Unchained" actress Daniele Watts accused police of violating her rights when they detained her.

Local

Number of New York City smokers increase, topping…

For the first time since 2007, there are  more than one million smokers in New York City, according to the New York City Department of…

Movies

Newsflash: Corey Stoll is still not a man

In director Shaun Levy's "This Is Where I Leave You," Corey Stoll stars as the oldest of four adult children (the others are played by…

Movies

If you don't like Simon Pegg's new film,…

Simon Pegg goes all out in "Hector and the Search for Happiness" as the titular psychiatrist stymied by modern life who embarks on a globetrotting…

Arts

Art in Chelsea: Don't miss these 3 galleries

We selected three sure bets for seeing cool art in the galleries of Chelsea.

Music

Robin Thicke blurs lines further with new 'Blurred…

"The reality is," said Robin Thicke about "Blurred Lines" in a court deposition, "Pharrell had the beat and he wrote almost every single part of the song."

NFL

Tom Coughlin says Giants 'beat themselves' against Cardinals

Head coach Tom Coughlin, who had a day to cool off and reflect, still sounded like he had a gnawing feeling in his gut.

NFL

Marty Mornhinweg accepts blame for Jets timeout fiasco

Jets fans looking for a scapegoat for Sunday’s timeout fiasco found a willing party on Monday: Marty Mornhinweg.

NFL

3 things we learned in Jets loss to…

The wheels came off for the Jets, who gave up 21 unanswered points after a brilliant first 20 minutes in a 31-24 loss at the Packers.

NFL

Victor Cruz catches case of the drops in…

The Giants dropped a tough, 25-14, decision to the undermanned Cardinals Sunday in their home opener. And drop was the operative word of the day,…

Travel

World's most hipster cities: Top 5

Travel blogger Adam Groffman tells us his picks for the Top 5 most hipster cities in the world.

Education

The top 5 regrets recent high school grads…

College application season can seem like a blur for many students - as test prep, campus visits and filling out a seemingly endless stream of…

Parenting

Tech execs tend to limit their kids' screen…

You probably got your iPad before Bill Gates's kids did.

Wellbeing

Wellbeing: Daybreaker returns, Ray Rice jersey trade, Sweet…

  Now that Ray Rice is no longer with the Baltimore Ravens — or any other NFL team — after video footage surfaced showing him…