Actress Jessica Alba has joined forces with Tobey Maguire's jewellery designer wife JENNIFER MEYER to launch a pair of necklaces for charity.

The pals have created two heart-shaped charms for rocker Bono's (Red) campaign in an effort to help raise funds for medication for pregnant HIV-positive women in Africa, to prevent the Aids virus from being transferred from mother to child.

One necklace, priced at $280 (£175), features an eight carat gold heart, while the other, retailing at $980 (£613), is made from 18 carat gold and has a heart studded with rubies.

Alba, who also runs non-toxic and eco-friendly baby and home product firm Honest, says, "We realised that hearts were a perfect metaphor for this project... It's an easy, elegant design that women can keep close to their hearts."

"It makes so much sense for us to collaborate on what we love, use the power of our platforms, and amplify what we do to help eradicate one of the worst diseases. Helping women and children has always been a priority for me."

Meyer adds, "We’re both mums so it really hits home. Imagine that feeling of transferring something to your child. It’s the worst thing in the world, and there are ways to prevent it."

The necklaces were launched via deal website on Wednesday (04Feb15).