Coronavac versus omicron should be ready in 3 months, says manufacturer

Chinese company Sinovac Biotech, responsible for manufacturing the Coronavac vaccine, said on Tuesday (7) that an updated version of the immunizing agent against the omicron variant should be available in three months.

In Brazil, the vaccine is produced in partnership with the Butantan Institute, in São Paulo. The company and the Brazilian laboratory carry out in vitro neutralization tests for the new strain, tests that must be completed within 15 days. Upon completion of this step, the company must begin human trials to assess safety and efficacy.

If the neutralizing action of the new formula against omicron is proven and the vaccine has good results in the tests, Sinovac intends to produce the updated version of Coronavac with a capacity of 1 billion to 1.5 billion doses per year.

The information was presented by Yaling Hu, principal researcher of Coronavac’s scientific studies in China, at an event at the headquarters of the Butantan Institute, in the west side of São Paulo.

In May, results of laboratory tests of the immunizing agent against different variants of the virus, including delta, showed the vaccine’s ability to block the entry and replication of the virus in cells.

The antibodies produced by the vaccine were able to equally block the action of the ancestral form of the Chinese virus and the variants D614G (the first mutation of the virus to appear), B.1.1.7 (British) and B.1.429 (Californian). In the case of variants P.1 (from Manaus), B.1.351 (South African) and B.1.526 (New York), the vaccine proved to be effective, but there was a reduction in the rate of neutralizing antibodies between 4 and 5 times .

The study was published in the form of correspondence — a brief but peer-reviewed article — in The Lancet, one of the most prestigious scientific journals.

Coronavac vaccine uses inactivated virus technology, that is, it uses the entire virus in the formulation that is killed and is unable to replicate. The use of the total morphology of the virus, and not parts of it, was considered by some experts as an advantage of immunizing against the new variants of Sars-CoV-2, since the mutations that occur in some parts of the virus, notably in the protein Spike S (or spike, used by the virus to enter cells) would not be as affected by antibodies produced against other parts of the virus, for example.

According to the director of the Scientific Development Center at Butantan, Sandra Coccuzzo, individuals vaccinated with Coronavac develop antibodies against the nucleocapsid protein, in the virus’s nucleus. For this reason, it is possible that vaccine protection will remain high even against the new variant.

The effectiveness and ability of the vaccine to prevent hospitalization and death against the new strain, however, must be evaluated in further studies of effectiveness, or real-life effectiveness. So far, information about whether the omicron causes milder infection frames is encouraging, but scientists are still awaiting more information from the virus before concluding.