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The findings come as the efficacy of Chinese vaccines comes under scrutiny, compounded by a lack of data on their protection against the more transmissible delta variant. CNBC found that weekly Covid cases, adjusted for population, have remained high in at least six of the world’s most vaccinated countries – and five of them depend on vaccines from China.
CNBC has identified 36 countries with more than 1,000 new weekly confirmed cases per million population as of July 6, using figures from Our World in Data, which compiles information from sources such as the World Health Organization, governments and researchers at the University of Oxford. CNBC then identified countries among those 36 where more than 60% of the population received at least one dose of the Covid vaccine.
These countries were six in number, and five of them use Chinese vaccines as part of their national immunization programs: the United Arab Emirates, Seychelles, Mongolia, Uruguay and Chile. The only country among them that does not depend on Chinese vaccines is the United Kingdom.
Sinopharm and Sinovac did not respond to CNBC’s requests for comment.
Several factors can cause a surge in Covid cases in countries with high vaccination rates. Vaccines do not provide 100% protection, so those that are vaccinated can still be infected. At the same time, new variants of the coronavirus may prove to be more effective in beating vaccines.
The best option for many countries
Many countries and territories that have approved vaccines by Sinopharm and Sinovac are developing countries that cannot compete with wealthier countries for vaccines developed in the United States and Europe.
“Some countries can accept a low level of circulation as long as there are relatively few severe cases and deaths from COVID-19,” Cowling, who heads the epidemiology and biostatistics division of the COVID-19, told CNBC. school, in an email. “This should be achievable with high coverage of any of the available vaccines. “
Yet some countries are avoiding Chinese vaccines. Costa Rica last month rejected a shipment of vaccines developed by Sinovac after concluding that it was not effective enough.
The effectiveness of the two Chinese vaccines is lower than that of Pfizer-BioNTech and Moderna, both of which have been shown to be over 90% effective.
Sinopharm’s vaccine is 79% effective against symptomatic Covid infections, according to the WHO, but its effectiveness among certain groups – such as people 60 and older – is unclear. Sinovac’s firing efficiency is around 50% to over 80%, depending on the country where the trials took place.
Some experts suggest that the technology behind the different Covid vaccines could explain the variations in their effectiveness.
The vaccines from Sinopharm and Sinovac trigger an immune response by exposing the body to a weakened or “inactivated” virus – a proven method that has been used by vaccines for decades. Pfizer-BioNTech and Moderna based their vaccines on a technology called messenger RNA, which asks the body to make viral proteins that induce an immune response.
Yet large phase three clinical trials have shown that inactivated vaccines have “high efficacy against serious illness and death” from Covid, Cowling said.
The professor told CNBC that peaks in Covid cases among some countries that use Chinese vaccines “tend to be outbreaks of mild infections with very few severe cases in fully vaccinated individuals.”
A study by the Kirby Institute at the University of New South Wales in Sydney claimed that in the Australian state of New South Wales, herd immunity could be achieved if 66% of the population received vaccines with 90% effectiveness against all infections.
The proportion of the population that needs to be vaccinated is 86% if the vaccine’s efficacy is 70%, and herd immunity is not achievable if the vaccine’s efficacy is less than 60%, has shown study.