Sinovac: Confidence in Chinese vaccines has suffered. But as coronavirus cases grow, some countries continue to strive

The Brazilian results suggest that CoronaVac is much less effective than vaccines developed by Pfizer-BioNTech and Moderna, which have an efficiency rate of about 95%. Russia says its Sputnik V vaccine has an efficacy of 91%, while the British vaccine, developed by Oxford University and AstraZeneca, has an average efficacy of 70%. The Sinovac vaccine has a lower efficiency rate than the local Chinese competitor, developed by state-owned Sinopharm, which he says has a 79.34% efficiency.

Under review

The Sinovac and Sinopharm vaccines are considered as potentially affordable and easily distributed vaccine candidates. Unlike the Pfizer-BioNTech and Moderna vaccines, the Chinese shots do not require expensive cold storage.

Sinovac has agreements with at least six governments, with plans to supply 46 million doses of the CoronaVac vaccine to Brazil, 50 million doses to Turkey and 7.5 million doses to Hong Kong. It will also supply 40 million doses of vaccine – the vaccine concentrate before it is divided into vials – to Indonesia for local production.

Thailand has ordered 2 million doses of CoronaVac and expects to receive the first 200,000 doses in February, while the Philippines has ordered 25 million doses, the first series of which, according to Reuters, is also expected to arrive next month.

However, following the release of the Brazilian trial data, other countries are now exploring potential plans.

According to the Ministry of Health, Brazil’s national vaccination program will begin on January 20.

Different efficiency rates

Part of the confusion about the Sinovac vaccination was about different efficiency rates and the data made available.

Data from Brazil, meanwhile, showed 50.38% efficiency for those who suffered very mild cases of Covid-19. But the light rose to 78% for mild to severe cases.

“It is difficult to interpret all this information without seeing the complete data sets. This highlights the problem of issuing data by press release rather than publishing in a peer-reviewed journal,” said prof. Lawrence Young, virologist and professor of molecular oncology at the University. of Warwick, said in a statement. “It also highlights the different approaches to regulatory approval requirements.”

There are several reasons why one trial may yield a different efficacy rate than another, including how it was performed, or that the vaccine may be more or less effective in different age groups or in different population groups.

A Sinovac representative told CNN that the difference in efficacy results was due to the different situations in countries where clinical trials were conducted.

“The results come from different populations, in different places with different diseases, and so it spans a relatively large variety,” the representative said.

But amid the vast amounts of new vaccine information appearing daily, analysts say there is a risk that people could get confused and lose confidence.

“There is a danger if people misunderstand science,” said Dr. Nikki Turner, director of the vaccination advisory center at the University of Auckland in New Zealand, said. “There’s a very important point here about trying to communicate the science behind these vaccines effectively. Especially when things are moving very fast.”

And effectiveness may not necessarily mean how effective the vaccine appears to be. “Once the vaccine moves from clinical trials to the community, you need to think about all the different aspects of what makes a vaccine work,” Turner said.

“Some vaccines may be more effective in reducing the disease, some vaccines may be more effective in reducing transmission, so it depends on what your purpose is.”

Go where it’s most needed

The concern that one country relies on a single vaccine with a lower efficacy rate is that it does not necessarily build up the necessary herd immunity in a population.

The debate took place in Australia this week, and some scientists have suggested that mass vaccinations be delayed.

Australia has obtained 54 million doses of AstraZeneca vaccine from Oxford University, with plans to start rolling it out later this year. However, some scientists – including the president of the Australian and New Zealand Society for Immunology – have argued that the vaccine will not provide herd immunity, and that the deployment plan should be discontinued, citing the low efficacy rate compared to the US. vaccines.

Experts have said that while scientific discussion of the availability of new data is a good thing, it should not detract from the fact that all vaccines approved in countries around the world have been proven to be safe and effective in killing and serious illness.

According to Johns Hopkins University, Australia has reported fewer than 30,000 cases of Covid-19 and fewer than 1,000 deaths. Several other countries in the Asia-Pacific region that have had similar success in controlling the pandemic have vaccine purchase agreements, but seem to be waiting for more information and to see what happens during the rollout of massive vaccines. countries hit hard, before taking their vaccination. own citizens.

New Zealand has been seen as a global model for dealing with the outbreak – since 18 November there has not been a local case. No vaccine has been approved in the country, although it has agreed with several vaccine developers for access to their candidates once local regulators give the green light.

Turner, of the University of Auckland, believes that waiting and evaluating new data on the safety and efficacy of vaccines will mean that the population will be able to have greater confidence in the vaccines.

“You have communities around the world that are nervous about new vaccines, new vaccine technology. Is it safe? Is it effective? So if we do not have to take emergencies with preliminary data, we are in a good position to have another few months and get more complete information on the efficacy and safety of these vaccines, ‘she said.

However, if you wait too long, it could be a new outbreak – especially in light of new, possibly more transferable variants.

“It’s a balance between getting the vaccine vaccinated in the country and the economy on track, and trying to prevent the disease from entering our country, as opposed to moving forward quickly and losing confidence in the community, “said Turner.

Jamie Triccas, professor of medical microbiology at the University of Sydney’s School of Medical Sciences, said that with the pandemic still raging, consideration should be given to making multiple vaccines from multiple providers – and it’s important to use them all.

“The most important thing is that we want to stop deaths, that’s the first thing you want. If you vaccinate as much as possible, you know that the vaccine may not prevent all people from getting infected, but it’s good to be serious. infections, hospitalizations and death, ”he said.

“The time is not on our side. We are in a situation where we have more deaths and cases per day than ever before. It is time to work together and move all vaccines out as quickly as possible, as long as they are safe. and is safe. has an efficiency level that is agreed to be effective. ‘