Sinovac: Confidence in Chinese vaccines has been shaken. But as coronavirus cases grow, some countries are still advancing

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

Under review

The Sinovac and Sinopharm vaccines were considered candidate vaccines to be potentially accessible and easily distributed. Unlike Pfizer-BioNTech and Moderna vaccines, Chinese vaccines do not require expensive cold storage.

Sinovac has agreements in place with at least six governments, with plans to supply 46 million doses of its 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 the vaccine in bulk – the vaccine concentrate before being divided into bottles – 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, of which the first batch is expected to arrive next month, according to Reuters.

However, after the release of data from the Brazilian trial, other countries are now reviewing potential plans.

Brazil’s national vaccination program is scheduled to begin on January 20, according to the Ministry of Health.

Different effectiveness rates

Part of the confusion about the Sinovac vaccine has to do with the different rates of effectiveness and the data made available.

Data from Brazil, on the other hand, showed 50.38% efficacy for those who suffered very mild cases of Covid-19. But the rate has risen to 78% for mild to severe cases.

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

There are several reasons why a trial may produce a different rate of effectiveness than another, including how they were conducted, or that the vaccine may be more or less effective in different age groups or different population groups, experts say.

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

“The results are from different populations, in different locations with different rates of morbidity and, therefore, cover a relatively large range,” said the representative.

But amid the plethora of new information about vaccines that come out daily, analysts say there is a risk that people will get confused and lose confidence.

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

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

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

Going where it’s needed most

The concern of a country relying on a single vaccine with a lower rate of effectiveness is that it may not necessarily increase the necessary herd immunity in a population.

That debate took place in Australia this week, with some scientists proposing a delay in mass vaccinations.

Australia has secured 54 million doses of the AstraZeneca vaccine from the University of Oxford, with plans to start rolling out later this year. However, some scientists – including the president of the Immunology Society of Australia and New Zealand – have argued that the vaccine will not provide collective immunity and implantation plans should be stopped, citing its low rate of effectiveness compared to vaccines made in the United States. United.

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

Australia recorded less than 30,000 cases of Covid-19 and less than 1,000 deaths, according to Johns Hopkins University. Several other nations in the Asia-Pacific region that have had similar success in controlling the pandemic have vaccine purchase agreements, but appear to be waiting for more data and to see what happens during the mass distribution of vaccines in most affected nations before to inoculate its own citizens.

New Zealand was hailed as a global model of how it handled the outbreak – it has not had a case broadcast locally since 18 November. No vaccine has been approved in the country, although it has signed agreements with several vaccine developers to access its candidates as soon as local regulators give the go-ahead.

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

“There are communities around the world that are nervous about new vaccines, new vaccine technologies. Are they safe? Are they effective? So, if we don’t have to rush emergency decisions with preliminary data, we are in a good position to wait a few more months and get more complete data on the efficacy and safety of these vaccines, “she said.

Waiting too long, however, can cause another outbreak – especially due to potentially more transmissible new variants.

“This is a balancing act between putting vaccines in the country to put the economy (on track) and trying to prevent the disease from entering our country, versus running and losing the trust of 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 going strong, several vaccines from multiple vendors should be considered – and it was important to use them all.

“The main thing is that we want to prevent deaths, this is the first thing you want. If you vaccinate as many as possible, you know that the vaccine may not prevent everyone from becoming infected, but they are good at preventing serious infections, hospitalizations and death, “he said.

“Time is not on our side. We are in a situation where we have more deaths and cases a day than ever before. It is time to cooperate and withdraw all vaccines as soon as possible, as long as they are safe and have a level of effectiveness. considered effective. “