Measles vaccinations need to be repeated to protect HIV-infected children

HIV-infected children may require repeat measles vaccination for protection, according to new research from the Johns Hopkins Bloomberg School of Public Health and other institutions. The researchers found that only half of the HIV-infected children who survived without antiretroviral therapy maintained protective antibody levels 27 months after receiving measles vaccine.

By comparison, 89 percent of children without HIV maintained their immunity, as did 92 percent of the HIV-infected children who were revaccinated in a mass measles immunization campaign during the 27 months of follow-up. The study results were published online June 19, 2007, by The Journal of Infectious Diseases, and will be included in the August 1, 2007, printed issue of the journal.

“Despite recent progress in measles control, measles remains an important cause of child mortality in sub-Saharan Africa,” says William Moss, MD, MPH, lead author of the study and an associate professor in the Bloomberg School of Public Health’s Department of Epidemiology. “The measles virus needs only a small proportion of susceptible children to sustain transmission and cause an outbreak. Vaccinated children with HIV could be susceptible to measles because of their waning immunity, impeding measles elimination efforts in regions with high HIV prevalence.”

The study enrolled over 690 Zambian children, 2 to 8 months of age, who came to the Chawama Clinic in Lusaka, Zambia for routine childhood vaccinations. Within six months of measles vaccination at 9 months of age, 88 percent of HIV-infected children developed protective measles antibody levels, as did 94 percent of children born to HIV-uninfected mothers and 94 percent of children who did not have HIV but were born to HIV-infected mothers. The proportion of HIV-infected children who developed protective antibody levels was comparable to those achieved by the other children. However, 27 months after vaccination, measles antibody concentrations were 75 percent lower in children infected with HIV at the time of vaccination and 72 percent lower in the children who became HIV infected after vaccination, compared with HIV-uninfected children.

The World Health Organization recommends a second opportunity for measles vaccination for all children, either through repeated immunization campaigns or a routine second dose delivered through the primary health care system. These study results suggest that this practice is especially important in regions of high HIV prevalence because of waning immunity among HIV-infected children.

“Sufficient resources must be invested to maintain high levels of population immunity against measles in regions of high HIV prevalence, as well as investing in strategies to prevent HIV infection and to treat HIV-infected people,” said Moss.

The study authors also recommend that additional research be conducted to determine the duration of measles immunity in HIV-infected children receiving antiretroviral therapy and their response to revaccination against measles.

Source: Johns Hopkins University Bloomberg School of Public Health

Related stories:

1 in 4 US teen girls got cervical cancer shot
(AP) -- About one in four teen girls last year got the groundbreaking vaccine that prevents cervical cancer, federal health officials reported Thursday.
Survey confirms parents' fears, confusion over autism
The first national survey of attitudes toward autism reveals that a small but significant percentage of people still believe the disease is caused by childhood vaccines. The survey of 1000 randomly selected adults was conducted for the Florida Institute of Technology.
Study shows no connection between measles, mumps, rubella (MMR) vaccine and autism
In a case-control study, the presence of measles virus RNA was no more likely in children with autism and GI disturbances than in children with only GI disturbances. Furthermore, GI symptom and autism onset were unrelated to MMR vaccine timing.
Most vaccine-allergic children can still be safely vaccinated, experts say
With close monitoring and a few standard precautions, nearly all children with known or suspected vaccine allergies can be safely immunized, according to a team of vaccine safety experts led by the Johns Hopkins Children's Center. Writing in the September issue of Pediatrics, the multicenter research team offers pediatricians a step-by-step tool for quickly identifying children with allergic reactions to vaccines, and a much-needed guide, they say, to safely immunize those who are allergic.
Giving an additional early vaccination may reduce measles outbreaks
Outbreaks of measles in developing countries may be reduced by vaccinating infants at 4.5 months of age as well as at the World Health Organization's recommended routine vaccination at 9 months, according to a study published on BMJ.com today.
Tool creates personalized catch-up immunization schedules for missed childhood vaccinations
A new downloadable software tool will help pediatricians, parents and other health care professionals determine how to adjust complex childhood immunization schedules when one or more vaccine doses aren’t received at the proper time.
Parents follow pediatrician advice on administering MMR vaccinations
News stories about an allegedly harmful link between the mumps, measles and rubella vaccine and the onset of autism had little effect on whether U.S. parents immunized their children, according to a review of immunization records and news stories. Parents’ decisions were more likely influenced by recommendations from their child’s pediatrician, the researchers said.
Measles break out in Tucson
Arizona health officials are concerned a measles outbreak in the Tucson area could spread across the state.

News discussion:

Medicine & Health news