A Two-Dose Schedule Given Over a Week Could Increase the Efficacy of HIV Vaccines

A two-dose schedule administered just one week apart can potentially increase the efficacy of an HIV vaccine, according to a recent study published in Science Immunology. 

Development of an effective HIV vaccine has been difficult because of how quickly the disease mutates. HIV rapidly evades the antibody response generated by vaccines. MIT researchers had previously demonstrated that administering a series of escalating doses of an HIV vaccine over a two-week period may address that challenge by generating larger quantities of neutralizing antibodies. However, as the researchers noted, a multi-dose vaccine regimen administered over a short time is not practical for mass vaccination campaigns.

In this novel study, researchers have now found that they can achieve a similar immune response with just two doses, administered one week apart. The first dose, given at a smaller quantity, prepares the immune system to deliver a stronger response to the larger second dose.

Study senior author Darrell Irvine said of the results via a press release: “Reducing the ‘escalating dose’ strategy down to two shots makes it much more practical for clinical implementation. Further, a number of technologies are in development that could mimic the two-dose exposure in a single shot, which could become ideal for mass vaccination campaigns.”