China's Vaccine road trip
With few COVID-19 cases at home, Chinese vaccinemakers have had to test the worth of their candidates abroad and four are in efficacy trials in 15 countries.
The two other Chinese players, Sinovac Biotech and China National Biotec Group (CNBG)—a subsidiary of one of the world’s largest vaccinemakers, the state-owned Sinopharm—are taking a different approach: vaccinating people with the whole, “killed” virus. This requires no sophisticated protein or RNA design or genetic engineering: Scientists simply inactivate the virus with a chemical (beta propiolactone) and mix it with an adjuvant (alum) that effectively puts the immune system on full alert by irritating it. In theory, such vaccines can produce broader antibody and T cell responses, because they contain the full set of viral proteins, rather than a single one such as spike. And unlike mRNA vaccines, which have to be stored at subzero temperatures, inactivated viruses requires no more than ordinary refrigeration.
Read the full article here.
By John Cohen