China responds to 'low-efficacy' vaccine fears

Gao later said his comments had been misinterpreted, telling the Associated Press that he was speaking about the effectiveness rates for "vaccines in the world, not particularly for China".

In an interview with the Global Times, he said that "the protection rates of all vaccines in the world are sometimes high, and sometimes low. How to improve their efficacy is a question that needs to be considered by scientists around the world".

The vaccines developed by Pfizer-BioNTech, Moderna and even Russia's Sputnik V shot have all shown protection rates of more than 90 percent, while Chinese vaccines have reported efficacy rates of between 50 to 79 percent.

However, most of what is known about the efficiency of Chinese vaccines comes from manufacturers and the countries where trials have been carried out.

79 percent or 50 percent?

In December, Sinopharm announced that the vaccine had an efficacy of 79.34 percent - although data from the peer-reviewed data on the final stage clinical trial research has not been published yet, triggering critics to point out the lack of transparency.

Meanwhile, Brazilian clinical trials showed early in January that Sinovac was only 50.4 percent effective against symptomatic Covid-19 - a far lower rate than those previously reported in Turkey (91.2 percent) or Indonesia (65 percent).

The minimum threshold for vaccine efficacy set out by the World Health Organisation (WHO) is at least 50 percent.

There are currently about a dozen Chinese vaccine candidates, but only five have received emergency approval in China and other countries.

No other vaccines have been approved in China, which has administrated 167 million doses as of Sunday (11 April), according to Our World in Data.

While China aims to vaccinate 40 percent of its population (560 million people) by the end of June, the country has been willing to supply countries worldwide with large quantities of its vaccines.

'Vaccine diplomacy'

Beijing has secured deals primarily with low and middle-income countries that have experienced difficulties obtaining Western jabs.

However, low-efficiency concerns and delayed deliveries might now undermine Beijing's so-called "vaccine diplomacy".

The vaccine developed by Sinopharm, a state-owned company, in Beijing has received the most emergency-use approvals globally so far, including Venezuela, Peru, Argentina, Egypt, Hungary, Serbia, and the UAE.

Serbia has one of the highest inoculations rates in Europe, mainly due to the country's large purchases of the Sinopharm vaccine.

President Aleksandar Vucic took the Chinese-developed shot last week, in a bid to encourage others to get the jab, amid vaccine scepticism and hesitancy in the Balkan state.

Neighbouring Hungary is the only EU member state that has approved the use of a Chinese vaccine, with its prime minister Viktor Orbán being among those who have received it.

Further afield, several countries have approved Sinovac's jab (also known as CoronaVac) for emergency use, including Brazil, Chile, Indonesia, Mexico, and Turkey.

In Chile, for example, national inoculation programmes did not pick up pace until Sinovac shipped in four million doses in late January. The country now has the third-highest vaccination rate per capita in the world.

Meanwhile, Turkey is facing delays in shipments from Sinovac pharmaceutical company, with patients being turned away recently because of a lack of doses.