The weekly number of new Covid-19 crown cases, adjusted for demographic factors, remains high in at least six of the world’s most highly vaccinated countries, five of which rely on vaccines from China. The effectiveness of Chinese vaccines is increasingly questioned, and data on their protection against the more transmissible Delta variant are lacking.
An analysis by the U.S. financial television network CNBC showed that most of the countries with high rates of both vaccination and Covid-19 infection rely on vaccines made in China.
However, experts say countries should not stop using Covid-19 vaccine from China, especially when supply shortages are particularly acute in low- and middle-income countries.
An analysis done by CNBC found that the weekly number of Covid-19 cases, adjusted for demographic factors, remains high in at least six of the world’s most highly vaccinated countries, and five of them rely on vaccines from China.
According to the analysis, as of July 6, CNBC identified 36 countries with more than 1,000 new confirmed cases per million people per week using data from its database, which compiles information from sources such as the World Health Organization, governments and researchers at Oxford University.CNBC then identified more than 60 percent of the population in those 36 countries that had received at least one dose of Covid-19 vaccine.
These countries ranked six, five of which rely primarily on the Chinese vaccine: the United Arab Emirates, Seychelles, Mongolia, Uruguay and Chile. One of the countries that does not rely on the Chinese vaccine is the United Kingdom.
A report in May by Mongolian news agency Montsam said the country had received 2.3 million doses of vaccine from Chinese state-owned company Sinopharm. That far exceeds the 80,000 doses of Russian Sputnik V and about 255,000 doses of Pfizer biotech injections that Mongolia had received as of last week.
Chile received 16.8 million doses of the China Kexin vaccine, compared with 3.9 million doses from Pfizer-BioNTech and a smaller number of the other two vaccines, Reuters reported last month.
The UAE and Seychelles relied heavily on the Chinese Koxin vaccine at the start of their vaccination campaigns, but both have recently introduced other vaccines. In Uruguay, Coxin vaccine is one of the two most commonly used vaccines, alongside Pfizer BioNTech.
Meanwhile, the UK has approved vaccines from Moderna, AstraZeneca-Oxford, Pfizer-BioNTech and Johnson & Johnson Janssen. In recent weeks, the UK has seen a surge in new crown cases as the more infectious Delta variant spreads.
In countries with high vaccination rates, several factors may have contributed to the surge in new crown cases. The vaccine does not provide 100% protection, so vaccinated individuals can still be infected. At the same time, new variants of the neo-crown virus may be better able to outcompete the vaccine.
However, epidemiologists say countries should not stop using the Covid-19 vaccine from China, especially if vaccine supplies are limited in low- and middle-income countries.
Many of the countries and regions where Sinopharm and Covid Holdings have approved vaccines are developing countries that cannot compete with wealthier countries for vaccines developed in the United States and Europe.
Countries may decide to use certain vaccines based on their long-term goals, Ben Cowling, a professor at the University of Hong Kong’s School of Public Health, told CNBC.
Cowling, head of epidemiology and biostatistics at the University, said, “Some countries may accept a lower prevalence level as long as COVID-19 causes relatively few severe cases and deaths.” He said, “This should be achievable with high coverage of any available vaccine.”
Nonetheless, some countries are still shunning the Chinese vaccine. Costa Rica last month rejected a vaccine developed by Kexing because it didn’t think it was effective enough.
The China National Vaccine and the Kexing vaccine are vaccines approved by the World Health Organization for emergency use.
The two Chinese vaccines are less effective than Pfizer-BioNTech and Modena, both of which have shown effectiveness of more than 90 percent.
The WHO says the effectiveness of the Chinese vaccine against symptomatic Covid-19 infection is 79%, but its effectiveness in certain groups (e.g., 60 years and older) is unknown. Trials done in different countries and regions with the Covid-19 vaccine have shown varying effectiveness rates of 50 percent to more than 80 percent.
Experts say it is not possible to directly compare results between clinical trials because each trial is set up differently.
The Sinopharm and Kexing vaccines trigger an immune response by weakening or “inactivating” the virus. This vaccine is a time-tested method that has been used for decades. The Pfizer-BioNTech and Modena vaccines are based on a technology called messenger RNA, which instructs the body to make viral proteins that induce an immune response.
“Inactivated vaccines are easy to make and known for their safety, but tend to produce weaker immune responses than some other vaccine types,” wrote Michael – Hyde, a senior researcher in global health at the University of Southampton in the United Kingdom, in an article he published on The Conversation website.
But in an email provided to CNBC, Cowling said large phase III clinical trials have shown that inactivated vaccines are “highly effective” at avoiding severe illness and death from Covid-19.