Sinovac's COVID-19 vaccine induces quick immune response: Study

Sinovac Biotech's experimental COVID-19 vaccine CoronaVac triggered an instant immune response but the level of antibodies produced was less than in people who had recovered from the condition, preliminary trial benefits showed on Wednesday (Nov 18).

While the early on to mid-stage trials were not designed to evaluate the efficacy of CoronaVac, researchers said it might provide sufficient protection, based on their experience with other vaccines and data from preclinical studies with macaques.

The study comes scorching on the heels of upbeat news this month from US drugmakers Pfizer and Moderna and also Russia that showed their experimental vaccines were a lot more than 90 % effective based on interim data from large, late-stage trials.

CoronaVac and four different experimental vaccines developed in China are undergoing late-stage trials to determine their performance in preventing COVID-19.

The Sinovac findings, posted in a peer-reviewed paper in medical journal The Lancet Infectious Diseases, originated from results in Phase 1 and Phase 2 clinical trials in China including a lot more than 700 participants.

"Our results show that CoronaVac is definitely capable of inducing an instant antibody response within four weeks of immunisation by giving two doses of the vaccine by a 14-working day interval," Zhu Fengcai, among the authors of the paper, said.

"We believe that this makes the vaccine ideal for emergency use during the pandemic," Zhu said in a statement released alongside the paper.

Researchers said the findings from large, late-stage studies, or Period 3 trials, will be crucial to determine if the immune response generated by CoronaVac was sufficient to protect persons from the coronavirus infections.

Sinovac happens to be running three Phase 3 trials found in Indonesia, Brazil and Turkey.

Naor Bar-Zeev from Johns Hopkins University, who was simply not mixed up in study, said the effects should be interpreted with caution until Stage 3 email address details are published.

"But even then, after Phase 3 trial completion and after licensure, we have to prudently remain careful," he said.

'ATTRACTIVE OPTION'

CoronaVac is among three experimental COVID-19 vaccines China has been working with to inoculate thousands of people under an emergency use programme.

Both other vaccines in China's emergency programme, both developed by institutes associated with Sinopharm, and another vaccine from CanSino Biologics, were also demonstrated to be safe and triggered immune responses in early and mid-stage trials, according to peer-reviewed papers.

Gang Zeng, a good Sinovac researcher mixed up in CoronaVac review, said the vaccine could possibly be an attractive option since it can be stored at normal fridge temps of 2 to 8 degrees Celsius and could remain stable for three years.

"(It) would offer some advantages of distribution to regions where usage of refrigeration is complicated," the writer said.

By contrast, vaccines developed by Pfizer/BioNTech and Moderna use a fresh technology called synthetic messenger RNA (mRNA) to activate the disease fighting capability against the virus and require far colder storage.

Pfizer's vaccine must be stored and transported in -70 degrees Celsius though it could be kept in a standard fridge for up to five days, or perhaps up to 15 times in a thermal delivery box. Moderna's prospect is likely to be stable at normal fridge temperature ranges for thirty days but for storage as high as six months it requires to be placed at -20 degrees Celsius.

CoronaVac is also being considered by Brazil and Indonesia for inoculations in the coming months.

Indonesia has sought emergency authorisation to start out a mass vaccination plan by the finish of the entire year and vaccines made by Sinovac and China's Sinopharm are slated to be used in the first stages of the plan.

Brazil's Sao Paulo also strategies to roll out CoronaVac as soon as January and provides decided on a supply cope with Sinovac.