(RxWiki News) Vaccinations can offer protection that prevents disease and saves lives. For HIV-infected patients, this protection may not last as long.
Vaccines contain specific agents called antigens — viruses or bacteria that have been killed or weakened so that they don’t cause disease. After immunization with vaccines, antibodies to those viruses help prevent future infection. People with HIV develop fewer antibodies, and whether these antibodies decrease faster over time has not been well studied.
Recently, a research team reviewed published studies and reported that protective antibodies in HIV-infected patients did not last as long after vaccination as they did in healthy people. They recommended that HIV patients may need revaccination or boosters sooner than people without HIV.
"Talk to your doctor about immunizations you may need."
The research team was led by Solen Kernéis, MD, PhD, from Paris Descartes University in Paris, France.
Dr. Kernéis’s team analyzed 54 studies in which HIV patients were vaccinated. Their goal was to find out what percentage of antibodies to the virus in the vaccine were present up to five years after vaccination and make recommendations for revaccinating HIV-infected people.
The researchers’ analysis of vaccinations in HIV-infected patients showed that the percentage of people with adequate antibodies to the hepatitis B virus was 71 percent after one year, up to 61 percent after two years and 40 percent after five years.
The percentage of people with adequate antibodies to the hepatitis A virus was 85 percent after four years. In children, the percentage with protective antibodies decreased slightly faster.
Antibody levels to measles-mumps-rubella viruses in adults varied, but the researchers estimated that in children immunized with one or two doses of the vaccine, protective antibodies would be present in 68 percent of children two years after vaccination and 40 percent after five years.
Immunity to measles virus was seen in up to 73 percent of children 15 months after vaccination, up to 49 percent of children after 28 months and in 30 percent of children 50 months after vaccination.
The antibody response to mumps or rubella viruses was only measured in children who had four years of treatment with anti-viral drugs for HIV. In these children, protective antibodies dropped over four years to both mumps and rubella viruses. Children who showed less HIV virus after treatment had higher levels of antibodies to mumps and rubella after vaccination than children who did not respond to HIV treatment.
Tetanus virus antibodies were present in adequate levels in 78 percent of children after four years.
“Our analysis confirmed that the duration of seroprotection [antibody to virus] was shorter in HIV-infected patients and that with current guidelines, a substantial proportion of patients would have lost protective antibodies before a booster was proposed," the authors remarked.
Based on the findings of their study, these authors recommended that HIV-infected patients should have antibody levels to many viruses measured periodically following vaccination so that they can be revaccinated sooner if they do not have adequate antibody levels.
The study authors recommended that antibodies to hepatitis B should be monitored yearly after vaccination in adults and every two to five years following vaccination in children.
Hepatitis A antibodies should be measured, the authors suggested, every five years after vaccination in people with increased risk — such as travelers, men who have sex with men, people with liver disease, infection risk from occupation or those who inject drugs.
They felt the recommendation for tetanus boosters could remain at 10-year intervals, but they suggested that initial vaccination with the measles vaccine should include two doses.
“Our analysis confirmed that the duration of seroprotection [antibody to virus] was shorter in HIV-infected patients and that with current guidelines, a substantial proportion of patients would have lost protective antibodies before a booster was proposed," the authors remarked.
The authors of this study noted that protection against infections is provided both by antibodies and cells of the immune system. Therefore, loss of antibody protection did not necessarily mean that all protection against infection was lost.
This research was published in the April 15 issue of Clinical Infectious Diseases.
Funding for the research was provided by a grant from Sidaction.
Two of the authors reported being sponsored by various pharmaceutical companies.
