A quick guide to Sinovac and Sinopharm – and what they mean for global protection.
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Why it matters
- China is now the world’s biggest exporter of COVID vaccines but outbreaks have dogged some rollouts.
- Experts say boosters against variants will likely be needed for all vaccines down the line.
Earlier this year, life beyond COVID shutdowns looked closer than ever for Chile, Mongolia, Bahrain and the Seychelles. All four nations were among the most vaccinated in the world, having secured large stores of China’s Sinovac and Sinopharm vaccines. But, by June, these four countries were battling some of the world’s worst COVID outbreaks. So are the vaccines failing?
A shipment of Sinovac lands in Cambodia in June 2021.Credit:Getty Images
What are China’s vaccines?
Since late 2020, China has exported hundreds of millions of doses of its Sinovac and Sinopharm vaccines to at least 70 countries and is relying on the shots for the mammoth task of vaccinating its own 1.4 billion people. “China is now the world’s biggest exporter of COVID vaccines,” says epidemiologist Michael Toole, who has been reviewing the rollout for the Burnet Institute. Vaccines work by training your body to mount an immune defence against the virus without you ever having to catch it. China’s vaccines use “inactivated” (dead) coronavirus to pull off the trick, Toole explains, as do our existing flu and polio vaccines. The Moderna and Pfizer vaccines developed in the West with new mRNA technology instead use a segment of the virus’s genetic code, while the AstraZeneca, Sputnik V and Johnson & Johnson shots use another harmless kind of virus to deliver the piece of COVID-19 needed to build immunity.
Do Sinovac and Sinopharm work?
As Russia did for its Sputnik vaccine, China skipped the final stage of clinical trials undergone by Western vaccines in order to roll out Sinovac and Sinopharm faster. But unlike with Russia’s shot, China’s data has been less robust since, limited by smaller sample sizes. Where Sinovac was rolled out in Brazil, it only halved the chance of developing symptoms of COVID (even a Chinese official commented off-hand that’s “not high”). But protection went up to 67 per cent in Chile and 85 per cent in Turkey. “I’d say they’re about on par with AstraZeneca,” says Toole. “Sinopharm seems better than Sinovac, it stops about 78 per cent of symptomatic cases, but it did its trials earlier, before certain variants were circulating.” Virologist Gary Grohmann, who consults for the WHO, says the data deficient for the Chinese vaccines (as well as both the misinformation and propaganda swirling around them) make their performance hard to assess, but he expects they will prove about 50 per cent effective. As with other vaccines such as AstraZeneca and Pfizer, however, both Sinovac and Sinopharm still have a very high chance of stopping you from dying of COVID, the key measure of any vaccine’s success. (And, while monitoring for side-effects after vaccination is considered less thorough in both China and Russia, Toole says no safety concerns have been flagged.) The World Health Organisation has approved both of China’s vaccines for emergency use, as it has Moderna, Pfizer, AstraZeneca and Johnson & Johnson. Grohmann says they will be now an important addition to the WHO’s COVAX scheme for delivering doses to developing nations, which has struggled to attract enough supply.
So why the concern?
No vaccine is guaranteed to stop the virus spreading (Pfizer and AstraZeneca are both thought to reduce the spread of COVID by up to half, for example) and so outbreaks have dogged even the world’s fastest vaccination campaigns. The UK has fully vaccinated more than half its population, mostly with AstraZeneca and then Pfizer, but is clocking up tens of thousands of cases a day again. Even Israel, where more than 60 per cent are vaccinated, has seen spikes, most recently driven by unvaccinated children. But in both countries, hospitalisation rates (and deaths) have stayed low, notes Deakin University chair of epidemiology Catherine Bennett, which is a sign the vaccines are working.
While there will likely be breakthrough cases for every vaccine (a small number of fully vaccinated people in the UK have recently died from the more contagious Delta variant, for example), in Mongolia both deaths and caseloads have significantly spiked again. It’s mostly using Sinopharm. Chile is largely relying on Sinovac, and its own recent surge in cases has overwhelmed hospitals, and sent the country back into lockdown. A study there found the chance of ICU admission still fell by 89 per cent among those fully immunised, but protection was much lower for those who had only had one dose. In Indonesia, where Sinovac is also leading the country’s immunisation rollout, at least 10 of the 26 doctors who died in June of COVID were fully vaccinated. “The death rates there are going up very quickly,” Toole says. People who have had two doses have also died in the Seychelles’ recent outbreak, though its government says most critical cases were not fully immunised.
In Thailand, when a recent leaked memo laid bare government doubts about the effectiveness of the Sinovac shot, experts promptly called for vaccinated healthcare workers to also get an mRNA booster. (The United Arab Emirates has also offered a third dose for people vaccinated with Sinopharm, amid concerns over its effectiveness). Professor of viral immunology at Murdoch University Cassandra Berry expects mixing and matching vaccines will be the way forward anyway to build broader immunity against the virus’s accelerating evolution. (“The Chinese vaccines will work well as your first dose primers to be paired then with say an mRNA,” says Grohmann.) But the COVID variants emerging since late 2020 may be widening the divide between one vaccine and another, Bennett says. “Lower [protection against milder cases] could become more significant when you’ve got a really rapidly spreading variant, or one that starts escaping those particular vaccines.”
Even Pfizer, which performed among the best in vaccine trials, has seen protection against symptomatic COVID driven by the Delta variant out of India drop from 94 per cent to 64, though protection from severe disease has stayed strong. Data on how well Sinovac holds up to Delta has been scarce, but Bennett says a recent outbreak in Brazil suggests it is not going well against variants. “That’s a worry because Sinovac is being widely distributed, and it was a really important initiative to try and get protection [around the world]. It probably did save lives there but may not really protect them to the level you’d want to see with these new variants.”
And, as Toole points out, when you have lower protection against COVID overall, as Sinovac does compared to Pfizer, it’s harder to build up herd immunity, when enough of the population is immune to the virus that it starts to slow and die out. “If the virus is still circulating, there’s more chance it will evolve again into new variants [which could evade] vaccines.”
Still, while all shots might not be created equal, experts stress any approved vaccine is better than none – without it, your natural protection is likely back down to zero.
What does it mean for the global vaccine rollout?
China’s vaccines already make up a decent chunk of the vaccination race and if they fail, Toole, Bennett and Berry say it could leave much of the world exposed. Sputnik, AstraZeneca and Johnson & Johnson are cheaper but China’s production capabilities are bigger than those of Russia, which has faced questions about how it will deliver on all its promised doses. And China’s vaccines don’t need to be stored at the freezing temperatures of the mRNA shots, making a rollout easier in developing nations. Indeed, both China and Russia’s “vaccine diplomacy” has helped poorer nations as the West hoarded supplies early on. (The US has since promised to donate tens of millions of its own vaccines abroad.)
Sri Lankan health workers administer second doses of Sinopharm in Colombo, Sri Lanka in mid June.Credit:Getty Images
Should people who’ve had Sinovac be allowed to travel?
The WHO thinks so – it’s calling on nations to recognise all its approved vaccines when considering granting exemptions on pandemic restrictions, including travel bans, to those who are immunised. Australia has flagged that rules will be relaxed down the line for those fully vaccinated but it has not approved China’s vaccines (or Russia’s Sputnik, which is yet to make the WHO approved list either, but which has proven about as effective in trials as Moderna and Pfizer). A number of expats have received Sinovac and Sinopharm overseas. “We can’t shut out one vaccine from our exemptions if it’s shown to work,” says Toole, who worries that politics, even racism, will hamper the take-up of both Chinese and Russian vaccines, no matter the science. He is himself fully immunised with AstraZeneca, a vaccine not approved by the US. “So I do wonder if that means I’ll have issues flying to the States myself.”
As Australia’s borders reopen, Bennett can imagine some extra measures applying at first for those who have had vaccines with less robust data such as Sinovac. “But to limit [exemptions] to only some approved vaccines long-term is messy and hard to defend, especially when everyone’s immune response is different anyway. Let’s just assume everyone who is vaccinated is coming in with 75 per cent protection, even if some have better.” If the variants change the picture significantly, say a variant really is shown to evade Sinovac or another vaccine, “that’s when you might have a difference in which ones you recognise,” Bennett says.
Berry agrees, adding “we could start requiring approved boosters to up people’s immunity before they travel. We do that already with other diseases.” But she says knowing when someone was vaccinated may end up being just as important as which vaccine they are given. “We still don’t really know how long immunity lasts. And with variants, these are shifting sands we’re on.”
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