En español | Older adults can safely take vaccines against pneumonia and shingles at the same time without compromising the effectiveness of either, researchers with Kaiser Permanente have concluded in a new study published in the journal Vaccine.
Their findings address a 2009 recommendation by the drugs' manufacturer, Merck & Co., that the zoster — or shingles — vaccine and pneumonia vaccine be given at least a month apart. As a result, vaccine experts feared fewer adults would get the zoster vaccine if it meant a separate trip to their doctor's office.
"It's tough enough to get adults vaccinated," said Kevin P. High, M.D., chief of infectious diseases at Wake Forest Baptist Health in North Carolina. "The data from this study suggest that if patients want to get both vaccines at the same time, we shouldn't hesitate."
Clyde Crumpacker, M.D., professor of medicine at Harvard Medical School, said the results of Kaiser's study suggest Merck's approach is "overly cautious," especially considering that half of Americans who live to age 80 or older are likely to develop shingles, characterized by a painful rash. As the Kaiser study notes, only about 7 percent of seniors have received the vaccine.
Rafael Harpaz, M.D., a medical epidemiologist with the Centers for Disease Control and Prevention, said the CDC's position has always been to give both vaccines together. "We did not think there was sufficient evidence [from Merck] to change good vaccination practices," he said.
Merck's recommendation was based on a clinical trial of 473 adults randomly assigned to receive the shingles vaccine, Zostavax, and pneumonia vaccine, Pneumovax, either at the same time or a month apart. Those who received the vaccines together had lower antibody levels, suggesting reduced immunity to shingles.
At Kaiser, the researchers took a different approach, reviewing the medical records of more than 14,000 older adults in which about half received the vaccines together and half received them separately. In a three-year period, 56 cases from the first group that had the vaccines together and 58 cases from the second ended up getting shingles, suggesting that the vaccines had the same effect regardless of whether they were taken together or separately.
Lead researcher HungFu Tseng said he was not surprised by the results. "We did not believe antibody levels would affect protection," he said.
In an email, Merck spokeswoman Jennifer Allen Woodruff stated that Merck is "pleased" that independent researchers are evaluating Zostavax but did not address whether Merck might change its recommendation.
Jennifer Anderson is a freelance health and science writer.