Covivac has been researched and produced by the Institute of Vaccines and Medical Biologicals (IVAC) since May 2020.— Photo ncov.moh.gov.vn

HÀ NỘI — The research team for the Covivac vaccine began to screen and recruit 375 volunteers to participate in the second phase of clinical trials from Wednesday in Vũ Thư District in the northern province of Thái Bình.

The move came after the Ministry of Health said Tuesday morning that it had approved the second phase of the trials.

Covivac has been researched and produced by the Institute of Vaccines and Medical Biologicals (IVAC) since May 2020.

The trial injection programme will start on August 18.

Volunteers will be divided into three groups. Members of the first group will each receive a 3-mcg dose of Covivac. The second group will receive a 6-mcg dose, and the third will receive a dose of AstraZeneca.

Dương Hữu Thái, president of IVAC, said that in this second phase the AstraZeneca vaccine would be used in place of a placebo, which would compare the immunogenicity of the two vaccines.

Normally, a placebo would be used by some volunteers, but complex developments in the pandemic meant they might not be protected from the virus if they received a placebo at this time, he said.

Accordingly, the research team decided to inject them with a vaccine instead. This method has also been used by some countries that had developed their own vaccines.

Thái said the second phase was set to finish on September 20. The research team would send the samples from the second phase to Canada for an independent evaluation.

Then, the research team would issue the assessment of the second phase of the clinical trials in November, he said.

Vũ Đình Thiểm, director of the Clinical Trial Centre under the National Institute of Hygiene and Epidemiology, said the volunteers must be over 18 years old, and even between 70-80 years old, including people with chronic diseases such as diabetes and hypertension if they were under stable treatment.

"If the second phase goes smoothly, the team will collect blood samples from volunteers 42 days after their first dose to evaluate the immunogenicity and neutralising antibodies of the vaccine," he said.

On day 57, the research team will conduct medical examinations and take blood samples from volunteers for evaluation before the research team proposes the third phase of clinical trials to the ministry.

Covivac is Việt Nam’s second coronavirus vaccine under clinical trials. The vaccine began the first phase of clinical trials on 120 volunteers aged from 18 to 59 on March 15.

The National Committee for Ethics in Biomedical Research under the health ministry last Saturday held an online meeting to evaluate the results of the first phase of the Covivac vaccine’s clinical trials.

The committee said the vaccine was evaluated as safe and had good immunogenicity or eliciting antibodies against the virus on all 120 volunteers.

Covivac is a viral vector vaccine, which is the same as AstraZeneca but uses a different cell substrate to produce it. —VNS