By ANDREA RODRIGUEZ | Associated Press Writer

HAVANA—In what could be an important breakthrough for developing countries, Cuban researchers said Wednesday they had developed a cheaper vaccine to combat a deadly childhood meningitis.

The vaccine protects against Haemophilus influenzae type b, or Hib, a major cause of meningitis and other dangerous infections among infants, the researchers said.

The announcement of the new synthetic version brought a standing ovation for Vicente Verez, head of the University of Havana’s Synthetic Antigens Laboratory. Verez presented his findings at a biotechnology conference here.

International researchers said they were excited about the announcement.

Before the development of a similar vaccine more than a decade ago, Hib was the biggest cause of meningitis among infants in the United States. The earlier vaccine has all but stamped out the disease in the western world, but it is too expensive for many poor countries to do mass immunizations.

Verez said the vaccine was tested on more than 4,000 people in Cuba, including 1,200 4-year-olds and 1,000 infants. The trials showed a 99.7 percent success rate in protection against Hib. Besides causing meningitis, Hib also causes other dangerous bacterial infections like pneumonia.

The Communist Party daily Granma reported Wednesday that 1 million doses of the vaccine were already in production here and that Cuban children would be immunized with the new vaccine beginning early next year.

Cuba in the past used the conventional version of the vaccine, but found it more costly and difficult to produce because it involves growing antigens in a bacterial culture.

“This technology opens up the field for other vaccines,” Verez said of the new synthetic.

Researcher Richard Schmidt, of the chemistry department at the University of Konstanz in Germany, said he had followed Verez’s research on the vaccine for many years.

“I was delighted to hear that he had so much success with this vaccine,” said Schmidt, who specializes in synthetic organic chemistry. “He was always very enthusiastic about it.”

Dutch researcher J.P. Kamerling of the chemistry department at Utrecht University called the vaccine “a step forward.”

“What has been presented here today is great,” Kamerling said.