However, roughly one in four already had protective levels of H1N1 antibody before the vaccine was administered, presumably due to prior exposure to the virus . When these were excluded, the response rate dropped to 61% in those who did … Low rate of immunoresponse to the novel split virion, inactivated, adjuvanted pandemic H1N1 influenza vaccine in HIV-1-infected patients. Nachman S et al. Safety of an inactivated H1N1 2009 H1N1 vaccine in HIV-1-infected pregnant women, …
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H1N1 in people with HIV: severity of disease generally unaffected …