Scientists warn that China’s Covid vaccine could offer almost no protection against Omicron.
Yale University found that two doses of CoronaVac were able to produce ‘undetectable” antibody levels.
The team stated that a Pfizer booster raised antibody levels in double-vaccinated recipients of the Chinese-made jab. However, it was only comparable to those who received two Moderna or Pfizer injections.
It was found that billions of people have been given the jab but are no longer protected from infection.
CoronaVac is approved in 50 countries by Sinovac, a Chinese pharmaceutical giant.
Professor Akiko Iwasaki, an immunobiologist at Yale and senior study author, warned ‘an additional booster shot — and possibly two’ may be needed in these countries.
This will be a signal to China that it cannot rely on Sinopharm and its own jabs.
China — which only reported 0.09 cases per million people yesterday, compared to the UK’s 1,357 per million — has reverted to draconian local lockdowns over the last month.
CoronaVac activates the virus in order to boost the immune system.
Because they are traditional, vaccine sceptics from the West have held the Chinese jab up as an alternative to the new mRNA jabs.
Yale University scientists found that no antibodies were produced by Sinovac after they double-jabbed 100 subjects with the drug. Analyses of blood taken from the same group 28-days after two Sinovac jabs (orange bar) showed that antibody levels rose compared to people who only received one. The researchers stated that the response to the Pfizer booster jab (orange bar) was similar to the one seen in those who received two Sinovac jabs. This vertical axis is not the same as how many antibody jabs were triggered by the test that measures antibodies.
Sinovac uses an inactivated form of the virus (pictured) to boost the body’s immune reaction. The vaccine — which can be stored at refrigerator temperature, making it easy to distribute to the developing world — has been authorised in around 50 countries
China — which only reported 0.09 cases per million people yesterday — has reverted to draconian local lockdowns over the last month (green line). China is following the zero Covid plan. It is a comparison to the UK, which yesterday had 1,357 cases per 100,000 people (purpleline).
Chile — the most boosted nation in the world, where 63 per cent of the population has been triple-jabbed — has relied on CoronaVac after striking a deal with China for 1.8million doses in 2020. The UK and Denmark are the two countries with the highest booster rates, 59% and 54%, respectively.
Yale University studied blood samples from over 100 CoronaVac-double-jabbed people.
They didn’t consider the vaccine to be a booster. However, third doses of the vaccine were being distributed in China beginning October.
However, even if you gave Moderna and Pfizer to two CoronaVac jabs recipients, your antibody levels were only comparable with those who received two CoronaVac jabs.
Professor Iwasaki said: ‘An additional booster shot — and possibly two — are clearly needed in areas of the globe where the Sinovac shot has been the chief source of vaccination.
We know from experience that booster shots in this group are necessary because even two doses mRNA vaccinations don’t provide enough protection against Omicron infections.
The risk of getting Covid is reduced by two Pfizer jabs.
Chile — the most boosted nation in the world, where 63 per cent of the population has been triple-jabbed — has relied on CoronaVac after striking a deal with China for 1.8million doses in 2020.
It is using AstraZeneca, Pfizer as booster jabs. This follows a series studies that showed the Chinese jab provided lower protection.
CoronaVac is also being used in Europe, Africa and the Middle East. According to Our World in Data, Oxford University has reported that 60 million doses were distributed in Europe.
Two doses of AstraZeneca and Johnson & Johnson’s jabs were found to produce a low antibody response against Omicron in studies, but real-world data often differs from trial data, because antibodies are only a narrow measurement of the complex immune response.
Pfizer’s Omicron vaccine, which is considered the standard, has been shown to produce 40 percent fewer antibodies than other variants.
The UK Health Security Agency says it offers Omicron protection of up to 40%, and boosters bring the number up to about 80 percent.
Yale researchers worked in collaboration with Dominican Republic scientists on the most recent study.
The doctors took samples of blood from 101 Dominican Republic residents who had been double-jabbed by Sinovac.
Participants were also asked to give a second blood sample 7 and 28 days after receiving a Pfizer boost. The booster was administered at least 4 weeks following the first jab.
These samples were given to Omicron by scientists. They also included the Delta virus that was previously predominant and the original version of the virus which was found in Wuhan.
These results were published in Nature Medicine. They show that double-jabbing with Sinovac didn’t produce neutralizing antibodies to super-mutant Omicron. This was the first time it had been detected in South Africa.
Their Omicron protection jumped 28 days after receiving a booster Pfizer jab. This was in contrast to the two Sinovac jabs.
The researchers stated that the responses were the same as those who double-jabbed with Moderna and Pfizer.
Researchers found that those who received two Sinovac injections plus a Pfizer booster had 10.1 times fewer Omicron antibodies than the original Covid strain. They also produced 6.3 times fewer Omicron antibodies than Delta.
Also, the researchers found that Omicron immunity was weak in those who were infected earlier with Covid.
Scientists warn that the two-dose immune response does not protect against Omicron. This finding prompted the UK to launch its winter booster campaign.
Omicron’s extensive mutations — most of which are on the spike protein which the virus uses to infect the body’s cells — make protection elicited by previous infection or vaccination less effective.
The reason is that vaccines exist to trigger an immune response against recognized spike proteins.
Their findings could complicate efforts against the more mild but transmissible Omicron strain, according to the team.
Professor Iwasaki pointed out that vaccines or prior infections trigger additional parts of your immune system, including T cells, which can kill and attack infected cells, and help prevent serious disease.
“But, we need antibodies in order to prevent infection and slow the transmission of the virus,” she cautioned.