Scientists develop two-dose vaccine strategy against HIV

Each year, more than 1o lakh people are newly infected with HIV, many without access to antiviral drugs.

Researchers from MIT have made significant strides in the development of a more practical HIV vaccine regimen, potentially requiring just two doses.

One of the main challenges in creating an effective vaccine has been HIV's rapid mutation, allowing it to evade the immune response. Previously, MIT scientists demonstrated that escalating doses of an HIV vaccine over two weeks could produce more neutralising antibodies. However, this multi-dose regimen is impractical for large-scale immunisation.

In their latest study, the MIT team found that administering two doses, one smaller and one larger, just a week apart, could generate a strong immune response similar to the more intense, multi-dose approach, according to a report in Interesting Engineering.

The first dose primes the immune system, enabling a more robust response to the second dose. This new method was developed through computational modeling and tested in mice using an HIV envelope protein as the vaccine.

Currently, a single-dose version of this vaccine is being tested in clinical trials, but the researchers are working towards setting up trials to test the two-dose schedule as well. This approach could also have broader applications for other vaccines, according to Professor Arup Chakraborty, a lead researcher on the project, told the publication.

Each year, more than 10 lakh people are infected with HIV, many without access to antiviral drugs. A successful vaccine could prevent many of these infections, the report said.

In the ongoing research, the team compared various dosing schedules and found that a two-dose strategy — administering 20 per cent of the vaccine in the first dose and 80 per cent in the second — produced antibody responses comparable to the seven-dose regimen.

This promising approach is now being tested in non-human primate models.