Sinovac wasn't great against the original strain, but against Omicron, Sinovac is basically worthless. A two-dose regimen provides literally no benefit, and three doses is only equivalent to unboosted, two-dose mRNA (aka, not really effective): https://news.yale.edu/2022/01/20/vaccine-used-much-world-no-...
Sinovac is trash, but politically China can't admit failure and buy the Western vaccines, and hence it's stuck with lockdowns.
Note that Hong Kong's Center for Health Protection (CHP) has consistently been way ahead of any other public health establishment in tracking and responding to COVID; they launched on-arrival rapid testing in March 2020 (!) and realized COVID was airborne, not fomite-transmitted, months before the CDC did. They've also consistently released provably accurate numbers. Hong Kong has had a bad response to COVID recently, but all of it is due to the bureaucrats in charge ignoring the CHP's scientifically-based health advice in favour of mandates handed down from the mainland government.
In any case, the numbers show that while Sinovac isn't as great as Pfizer, it's much better than being unvaccinated. The case fatality rate among 80+ year olds who got covid is 15.68% for unvaccinated people, 3.98% for those with 2 doses of Sinovac and 1.73% for those with 2 doses of Pfizer. For 70-79 year olds it's 5.28%, 0.6% and 0.33% respectively. Note that all of Hong Kong's recent wave was from Omicron.
We forget how lucky as a civilization we were to develop mRNA vaccines in response to COVID, and how much better than expectations they were. We would have been thrilled with the efficacy of Sinovac. So while Sinovac is definitely worse than Pfizer, it's misleading and alarmist to say that it's 'basically worthless.'
The report you're linking to starts from Dec 31, when Delta was still widely circulating (and which had much higher fatality rates, further compounding issues with a raw measurement of "case fatality" for COVID-19). It doesn't attempt to isolate performance against specific strains, unlike the Yale research, which does. It's also a biased sample, since the Pfizer vaccine ("Comirnaty") isn't approved in China, so the people who have it are likely significantly different in many respects from those who got Sinovac ("CoronaVac"). The unvaccinated groups are also likely a biased sample. It's a raw data dump: useful if you have nothing else, but we have peer reviewed research that does attempt to correct for those kinds of flaws on exactly this topic.
If you think I'm being "misleading," here's a direct quote from Yale statement:
"However, those [Sinovac] vaccinations alone are of no help against the widely circulating omicron variant, shows a new study by researchers at Yale and the Dominican Republic. The results are published in the journal Nature Medicine.
An analysis of blood serum from 101 individuals from the Dominican Republic showed that omicron infection produced no neutralizing antibodies among those who received the standard two-shot regimen of the Sinovac vaccine.
...
But when researchers compared these samples with blood serum samples stored at Yale, they found that even those who had received two Sinovac shots and a booster had antibody levels that were only about the same as those who’d received two shots of the mRNA vaccines but no booster shot."
That's pretty much exactly what I posted! So no, I don't think I'm being misleading.
Regardless, even if you suppose the entire HK dataset is 100% Omicron cases, and ignore the sample biases, it's still pretty poor compared to Pfizer; the OP claimed they were roughly the same, which I was refuting.
These are rates per 100,000 for vaccinated, boosted and unvaccinated from Ontario (population 14 million). I don't see much benefit against infection to those with 2 or 3 mRNA doses.
The most recent datapoints (7 day average):
- Not fully vaccinated: 14.86 cases per 100,000 people
- Fully vaccinated: 17.39 cases per 100,000 people
- Vaccinated with booster: 26.89 cases per 100,000 people
For infection rates, perhaps there is a bit of a confounding factor of vaccinated people being less careful (eg unmasking) due to confidence in their vaccination status?
The deaths by vaccination status stats on that same page are pretty interesting.
My thought on the most likely confounding factors is both requirement and proclivity to get tested. Vaccinated/boosted folk are more likely to be in situations requiring testing, thus finding more mild or asymptomatic cases. I'm not sure on who is more likely to get tested of their own volition for mild symptoms and could see arguments both ways, but could see it being a factor.
Agreed, the deaths by vaccination status shows a stronger benefit, particularly with age.
The mrna vaccines have an impact on transmission / infection of omicron for about 4-6 months (there is longer-lasting protection against severe illness etc).
This leads to very confusing debates, the "headline" stats used to sell the vaccine demonstrate high effectiveness (they tend to use data from the 4-6 month window where they know it will look good).
The metastudies / long-term studies tell a more nuanced story.
7-day average isn't particularly worthwhile for Omicron, which peaked months ago. Most people who were going to get it already got it.
Ontario changed the way it reports COVID data in March, and thus finding prior data is annoying on my phone for Ontario specifically. But pretty much every other data source I've looked at agrees: during the Omicron peak, the vast, vast majority of cases per 100k were in the unvaccinated.
Sinovac wasn't great against the original strain, but against Omicron, Sinovac is basically worthless. A two-dose regimen provides literally no benefit, and three doses is only equivalent to unboosted, two-dose mRNA (aka, not really effective): https://news.yale.edu/2022/01/20/vaccine-used-much-world-no-...
Sinovac is trash, but politically China can't admit failure and buy the Western vaccines, and hence it's stuck with lockdowns.