If he is just trying to ignore the other dogs by sniffing and looking away, then I wouldn't stress about it too much as long as he is capable of interacting well with you while in the presence of other dogs. Just make sure he isn't exposed to negative dog interactions and he may just need time to move past the attack. If he openly shows signs of stress though, I would want to do something about this now so his issues with other dogs don't worsen.

Take it slow and don't push him to hard beyond his comfort levels, it might have the opposite effect of what you want. So no dog parks, no face to face introductions for a while. Get him into an obedience class too - that will be a good structured place for him to learn and bond with you while other dogs are present and will let you and a trainer see his behaviors around other dogs to best determine what issues there are.

You can also try this method over a long period of time with super high value treats that you only use when he's around other dogs. Find a public place where there are leashed dogs but where you can get a large safe distance away from the other dogs in a parking lot across the street or somewhere far away like that. A dog park parking lot might be too much at first since the dogs on the other side of the fence will be loud and rowdy but maybe a regular park where people will be walking their dogs or even an open shopping center parking lot with a pet store where you know people will be coming in and out with their dogs would be a good place to start. If he is reacting negatively (tail tucked, whining, trying to run away or hide, lip licking etc...) to the dogs passing by, you are too close. Basically you need to be below his threshold and very slowly close the distance to desensitize him to other dogs while changing how he feels about other dogs with high value rewards.

Also try to find someone you know or a dog training center that can set you and your dog up with super calm, friendly dogs that can be used as control dogs for him to re-learn that dogs are okay and how to properly behave around them.

Also a consultation with a behaviorist would be a good place to start and can help you nail down a socialization plan and determine what will be best for him. Some local shelters offer discounts on private consults if you just adopted from them.