CanSino Vaccine Produces Immune Response

A July 20, 2020 article in The Lancet reported that the results of a trial for CanSino Biologics’ COVID-19 vaccine showed the non-replicating adenovirus type-5 (Ad5)-vectored vaccine was safe and induced “significant immune responses in the majority of recipients after a single immunization.”

The randomized, double-blind, placebo-controlled, Phase II trial of the vaccine was conducted in Wuhan, China for more than 500 healthy adults aged 18 years or older. Participants received injections of 1×10¹¹ viral particles per mL, 5×10¹⁰ viral particles per mL, or a placebo.

The vaccine induced neutralizing antibodies in 59% of the 1 × 10¹¹ dose group participants and 47% of the 5×10¹⁰ dose group participants, and seroconversion of binding antibody in 96% of the 1×10¹¹ dose group participants and 97% of the 5×10¹⁰ dose group participants.

Positive specific T-cell responses were found in 90% of participants in the 1×10¹¹ dose group and 88% of participants in the 5×10¹⁰ dose group. 95% of participants in the 1×10¹¹ dose group and 91% of the recipients in the 5×10¹⁰ dose group showed either cellular or humoral immune responses at day 28 post vaccination, according the article.

The authors noted that patient age and pre-existing anti-Ad5 immunity of the participants could have affected the candidate vaccine's safety and immunogenicity.

In a separate article published online in The Lancet on July 20, 2020, AstraZeneca reported that interim results from an ongoing Phase I/II trial of its AZD1222 vaccine candidate against the SARS-CoV-2 virus showed the vaccine was tolerated and generated immune responses in all evaluated patients.

Source: The Lancet