ISV COVID-19 vaccine update highlights Chinese vaccines

Last week the International Society for Vaccines hosted it’s fifth COVID-19 vaccine update in its Virtual Congress. The latest update looked at vaccines being produced in China by 3 companies: CanSino Biological, Sinopharm CNBG, and Sinovac Biotech, Co., Ltd.

The CanSino vaccine is a recombinant adenovirus 5 vector based COVID-19 vaccine. The data was in participants aged 18 years and older and 28 days after the vaccination was received. Efficacy was 65.28 for symptomatic cases and 90.07 for severe cases. Adverse reactions seen include lethargy, fever, headache, nausea, diarrhea, vomiting, myalgia, pain, swelling, and redness. The average duration of the reaction 2 days, except for fever, which was 1 day. No serious adverse events were found. No statistically difference in the incidence of medically attended adverse event was seen between the vaccine and placebo groups. The vaccine appears to be quite effective against variants, although more research needs to be done with the South African variant. The company is currently running a trial in children and adolescents.

The Sinopharm CNBG is an inactivated vaccine. The active component is inactivated severe acute respiratory syndrome coronavirus 2 virus and the adjuvant used is aluminum hydroxide. Its dose is 6.5U/dose and it comes packaged in a prefilled syringe that should be stored at 2 to 8 degrees Celsius with an efficacy of around 72 in adults aged 18 and older. The majority of adverse events were grade 1 and the placebo group had higher incidence of grade 1 adverse events. Some adverse events were erythema, pain, and swelling at the injection site; fever; and fatigue. Pain at the injection site was the most common event after dose 1. Serum samples indicate that the vaccine has good cross-neutralization abilities for fighting variants. A trial has been completed in children aged 3 to 17 years and will start the approval process soon.

The Sinovac Biotech, Co., Ltd. vaccine called CoronaVac is also an inactivated COVID-19 vaccine. Its research and development started in early 2020 and Phase III trials started in Brazil on July 21, 2020. Other countries for the Phase III trial included Turkey, Indonesia, and Chile. Participant were either general population, medical staff, or a mix of both. The efficacy of the vaccine was found to be 50.65% in Brazil, 83.5% in Turkey, and 65.3% in Indonesia. Efficacy for hospitalized cases was 100%. The most common adverse events were pain at injection site, headache, fatigue, and myalgia. The vaccine has been approved for emergency use by 40 authorities and 180 million doses have been given globally. Vaccine trials for CoronaVac will be starting soon in children.

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Reference

1. International Society for Vaccines. 5th COVID-19 Vaccine Update; April 27, 2021; virtual. Accessed May 4, 2021.