I suggest you see the nurse at your own doctors, they will have one who specialises in travel jabs etc. She/he will be able to recommend alternatives. Other than that you could just smother yourself with mozzy cream and spray (keep extra with you at all times), use deterrant sprays and coils in your rooms, plus mozzy nets (check for holes. You can buy and take one with you). All that is useful anyway as there are other insects. Wear long sleeves and cover your legs in the evenings. Keep feet sprayed if bare. Avoid standing water and wet areas where they breed. Make sure netting in windows have no holes. A lot of expats dont bother with anti-malerials any more as it has become so resistant anyway. Some areas particularly should be avoided, you could do some research on that but Kilifi in Mombasa used to be particularly bad. Also research online as to whether mozzies are attracted to pregnant women. Sounds mad but creatures can smell hormones and there is something at the back of my mind about this. I hope that doesnt sound scary, I wouldnt ne quite so careful myself but thats minus pregnancy! Good luck, I hope you enjoy your trip.