[8] In later years he continued his research at the University of Navarra in Spain and wrote on a wide range of topics such as the distinction between science and pseudo-science, the emergence of genetically modified organisms (GMOs) and comparative health care policy.

He then stayed - as the first U.S. Public Health Service funded foreign research fellow from Switzerland - at Barnes Hospital at Washington University in St. Louis from 1958 to 1960 under the guidance of Prof. Herman Eisen.

[9][10] Starting in 1961, after his return to Switzerland, he established himself as an independent researcher and eventually full professor (Ordinarius) at the University of Bern with initial support from the Swiss National Science Foundation.

During this time he investigated a growing variety of topics such as hapten-antibody interactions, contact dermatitis, immunological tolerance to simple chemicals, delayed (type IV) hypersensitivity and lymphocyte proliferation, among others.

His main contributions range from the characterization of the molecular causes of penicillin allergy,[14] the suppression of allergic reactions using hapten inhibition, the international standardization of allergens[15] to the study of Immunoglobulin E (IgE) synthesis and associated receptors, and the development of new diagnostics techniques such as in-vitro cellular assays[16] as well as flow cytometric tests.

He subsequently founded the Centre Medical des Grand-Places (CMG) company with a number of investors, including the Japanese pharmaceutical firm Nippon Zoki.

One of the highlights of these activities was his chairmanship of the XIIIth IAACI Congress in Montreux in 1988 with 5,600 participants[21] Alain de Weck received several awards and recognitions for his scientific work including, among others: After his retirement[22] from the University of Bern in 1993[11] Alain de Weck remained active as an Extraordinary Professor at the pontifical University of Navarra in Pamplona, Spain where he collaborated on further development and validation of flow cytometry for immunological testing,[17] as well as a frequent columnist in newspapers voicing his opinion on a wide variety of topics such as the distinction between true science and pseudo-science, the immunological aspects of genetically modified organisms (GMOs) and the future of health care policy in different countries.