A study on the effectiveness of the yellow fever vaccine among people living with HIV yields yet another reason that universal access to effective consistent antiretroviral medicine for people with the virus is important to global public health.
The study, published in the recent Clinical Infectious Diseases found that the yellow fever vaccine offers long-term protection against the vector-borne disease for people living with HIV that is comparable to the protection gained by people without the virus, but only if the virus is controlled at the time of vaccination, and if treatment continues uninterrupted.
The effectiveness of the yellow fever vaccine is essential to the control of the disease, for which no effective antiviral treatment exists, is endemic in areas where HIV prevalence is high as well, and poses an increasing threat in crowded urban settings. Because the vaccine poses a potential risk to people with severely compromised immune systems, the vaccine has been recommended for people with HIV only in the absence of symptoms of illness, and with a minimum immune cell count of 200. Whether or not people with HIV require a booster vaccination has remained unclear.
Researchers tracked immune responses following yellow fever vaccination among 247 people living with HIV who are part of a longitudinal study group, over one, five, and 10 years. They found the primary factor linked to ongoing protection from yellow fever vaccination 10 years later was control of HIV at the time of innocculation. They recommend a followup booster after 10 years for people with controlled viruses at original vaccination, and suggest earlier follow-up boosters could benefit people with HIV whose virus was not controlled at the time of the first innocculation.
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