Covid-19 outbreaks may not mean Chinese vaccines have failed

In Mongolia, hospitals are overwhelmed. In the tiny archipelago of Seychelles, more than 100 new Covid-19 cases are being reported each day. Chile is reporting thousands of daily cases.

What links these countries is that they have each fully inoculated more than 50% of their populations, largely with Chinese-made coronavirus vaccines. And that's raised questions over the vaccines' efficacy. If the Chinese vaccines aren't working, that's a huge problem.

Experts say that while these Chinese vaccines might not be as effective as some, they aren't a failure. No vaccine gives 100% protection against Covid-19, so breakthrough cases are to be expected. The crucial metric for measuring success, they say, is preventing deaths and hospitalisations.

China has two vaccines authorised for emergency use by the WHO, Sinopharm and Sinovac. Both use inactivated viruses to prompt an immune response in the patient, a tried and tested vaccine method.

So far, trials show Sinopharm and Sinovac have a lower efficacy against Covid-19 than their mRNA counterparts. In Brazilian trials, Sinovac had about 50% efficacy against symptomatic Covid-19, and 100% effectiveness against severe disease, according to trial data submitted to the WHO. Sinopharm's efficacy for both symptomatic and hospitalised disease was estimated at 79%. Experts say the outbreaks in places that used Chinese vaccines are in line with what we would expect from these efficacy rates. "If we want to bring down the severe cases (and) the number of deaths, the Sinopharm, Sinovac can help," said Jin Dong-yan, a professor in molecular virology at Hong Kong University.

Some people who are getting vaccinated with Sinovac or Sinopharm are still dying of Covid -- although these breakthrough cases are possible with any vaccine. In Indonesia, which the Red Cross warned this week is "on the edge of catastrophe," at least 88 doctors died of Covid-19 between February and June 26. At least 20 were fully vaccinated with Sinovac. Dr Hermawan Saputra, an epidemiologist and member of the Indonesian Public Health Experts Association, said more virulent strains of Covid-19 may have reduced the efficacy of the vaccines.

The issue of inoculated people dying from Covid-19 is not contained to Chinese vaccines. A Public Health England report in June found that of the 117 people who died within 28 days of testing positive for the Delta variant in the UK, 50 had received two doses. The UK is using Moderna and Pfizer/BioNTech, which are mRNA vaccines, and Oxford/AstraZeneca, which uses a different technology.

Getting a Chinese vaccine is still better than nothing, said Scott Rosenstein, director of the global health programme at Eurasia Group.

"In places where that's the only option, it still remains the best decision to take it," he said.