I would like to travel abroad but unfortunately had a massive immediate allergic reaction to vaccinations as a child. are there any alternatives?

It depends on what: the reaction was. Not all vaccinations are the same and some have changed since you were younger. Please consult with your own primary care doctor or an infectious disease consultant. You may also be able to get more information and advice on Health Tap Prime. That way you can upload what vaccines you had and what you reacted to and get expert advice from one of us.