In their fundamental paper on cubic variance functions (VFs), Letac and Mora (The Annals of Statistics, 1990) presented a systematic, rigorous and comprehensive study of natural exponential families (NEFs) on the real line, their characterization through their VFs and mean value parameterization. They derived a construction of VFs associated with NEFs of counting distributions on the set of nonnegative integers allowing to find the corresponding generating measures. As EDMs are based on NEFs, we introduce in this paper two new classes of EDMs based on their results. For these classes, we derive their mean value parameterization and their associated generating measures. We also prove that they have some desirable properties, such as overdispersion and zero inflation in ascending order, making them as competitive statistical models for those in use in both, statistical and actuarial modeling. To our best knowledge, our classes of counting distributions, have not been introduced or discussed before in the literature. To show that our classes can serve as competitive statistical models for those in use (e.g., Poisson, Negative binomial), we include a numerical example of real data. In this example, we compare the performance of our classes with relevant competitive models.