ABSTRACT
El texto presta atención las condicionantes sociales principales de la obtención de la vacuna Abdala como proceso social. El primero, histórico fundacional, se relaciona con la actitud científica del médico cubano Tomás Romay y Chacón ante el conocimiento y la práctica de la medicina; el segundo, político de partida, tiene que ver con importantes decisiones políticas tomadas por el gobierno revolucionario cubano a partir de 1959 que sentaron las bases para las políticas públicas de ciencia, tecnología e innovación; el tercero, educativo revolucionario, más cercano en el tiempo, remite a la educación patriótico-revolucionaria adquirida por quienes iniciaron la biotecnología en Cuba, que les permitió resultados relevantes en los comienzos de este campo a nivel internacional; el cuarto, organizativo tecnológico, remite a las formas organizativas innovadoras empleadas en la obtención de la vacuna Abdala. El objetivo general que se persigue es caracterizar los referidos condicionantes principales.
SUMMARY The text pays attention to four main social conditions of obtaining the Abdala vaccine as a social process. The first, foundational history, is related to the scientific attitude of the Cuban doctor Tomás Romay y Chacón towards the knowledge and practice of medicine; the second, starting political, has to do with important political decisions taken by the Cuban revolutionary government from 1959 that laid the foundations for public policies on science, technology and innovation; the third, revolutionary education, closer in time, refers to the patriotic-revolutionary education acquired by those who started biotechnology in Cuba, which allowed them to obtain relevant results at the beginning of this field at an international level; the fourth, technological organizational, refers to the innovative organizational forms used to obtain the Abdala vaccine. The general objective pursued is to characterize the aforementioned main determining factors.
ABSTRACT
Developing affordable and easily manufactured SARS-CoV-2 vaccines will be essential to achieve worldwide vaccine coverage and long-term control of the COVID-19 pandemic. Here the development is reported of a vaccine based on the SARS-CoV-2 receptor-binding domain (RBD), produced in the yeast Pichia pastoris. The RBD was modified by adding flexible N- and C-terminal amino acid extensions that modulate protein/protein interactions and facilitate protein purification. A fed-batch methanol fermentation with a yeast extract-based culture medium in a 50 L fermenter and an immobilized metal ion affinity chromatography-based downstream purification process yielded 30-40 mg/L of RBD. Correct folding of the purified protein was demonstrated by mass spectrometry, circular dichroism, and determinations of binding affinity to the angiotensin-converting enzyme 2 (ACE2) receptor. The RBD antigen also exhibited high reactivity with sera from convalescent individuals and Pfizer-BioNTech or Sputnik V vaccinees. Immunization of mice and non-human primates with 50 µg of the recombinant RBD adjuvanted with alum induced high levels of binding antibodies as assessed by ELISA with RBD produced in HEK293T cells, and which inhibited RBD binding to ACE2 and neutralized infection of VeroE6 cells by SARS-CoV-2. Additionally, the RBD protein stimulated IFNγ, IL-2, IL-6, IL-4 and TNFα secretion in splenocytes and lung CD3+-enriched cells of immunized mice. The data suggest that the RBD recombinant protein produced in yeast P. pastoris is suitable as a vaccine candidate against COVID-19.