China’s second COVID-19 wave to be smaller than its first peaking at 11 million cases a week, predicts Airfinity

China is facing its second wave of COVID-19 as the XBB variant surges across the country, Airfinity predicts this wave will be smaller than last year’s outbreak. 

Our modeling estimates the wave will peak at the beginning of June at around 11 million per week, with 112 million people being infected during this resurgence. 

This analysis is in contrast to estimates published recently by the Chinese respiratory disease specialist Zhong Nanshan who says cases will likely peak at 65 million a week by the end of June. Airfinity’s prediction of cases peaking at 11 million a week is six times lower than Nanshan’s estimate.

This discrepancy, in part, might be based on the inclusion of asymptomatic cases. Airfinity’s model is inherently a forecast of symptomatic cases based on the methods used. Zhong’s estimates have not been explicitly stated to include asymptomatic and symptomatic cases, it is likely that these values include both.

Officially reported data to the WHO on case rates is significantly lower than both estimates. WHO reported a total of 5,621 cases in the week ending 28 May 2023 in China. China stopped mass testing for the virus last year and with it, data ceased being representative of the virus’ transmission across the country.

Airfinity estimates deaths from China’s first re-infection wave to be 629,000 based on the case fatality ratios of similar countries that have recently experienced XBB driven waves. This is significantly less than the 1.3-2.1 million lives estimated to have been lost when the first COVID-19 outbreak swept through the country last year.

As China moves toward endemicity, it is expected that it will undergo multiple waves, especially in the Omicron era where the variant replacement rate has accelerated, leading to more frequent waves. This has been seen in several countries, including Japan and South Korea, both of whom followed zero-COVID strategies, similar to China.

Airfinity’s COVID-19 epidemiologist Dr Tishya Venkatraman says, “We expect the second wave in China to be smaller and less severe than its first despite the impact of the new XBB variant. This is due to China experiencing a large wave around six months ago which provided protection to millions, booster uptake increasing since the last wave, and anecdotal evidence from the country does not suggest hospitals and morgues being overwhelmed as they were during the last wave.

“Even though the ongoing wave is likely to be smaller, it could still lead to a large number of deaths because of the size of China’s ageing population. We have seen this in Japan where the latest wave caused a significant number of deaths despite having high vaccine coverage and underlying population immunity from previous waves.”