Health

China shifts focus to variant-specific vaccines as it faces an imminent Omicron wave

XBB subvariant has potential to wreak more havoc in China as large number of people immunologically susceptible 

 
By Taran Deol
Published: Wednesday 24 May 2023
When Omicron first ripped through China a few months back, it impacted the most immunologically susceptible population in the world. Photo: iStock

Less than a month after the World Health Organization (WHO) announced an end to the COVID-19 global health emergency on the grounds of cases recording a downward trend for the past year, China stands out as an anomaly. The country is expected to record about 65 million new infections every week toward the end of June, fuelled by the XBB Omicron subvariant of the SARS-CoV-2 virus. 

Regional news outlets cited respiratory disease specialist Zhong Nanshan on his estimates regarding how the upcoming wave of cases will behave in the backdrop of waning immunity in the country. Nanshan spoke at a biotech conference in the southern city of Guangzhou.

The rise in cases projected right now is expected to be milder than what China saw in December 2022 and January 2023, when nearly 37 million infections were recorded in a single day.

When Omicron first ripped through China a few months back, it impacted the most immunologically susceptible population in the world. This is a big reason why the wave was far more fatal here than in other parts of the globe. 

In December 2022, the Institute for Health Metrics and Evaluation, an independent population health research centre at the University of Washington Medicine, had estimated over 300,000 deaths in China in the coming months.

More than a million deaths were estimated for 2023 because China “has a large number of people who have never gotten COVID or been vaccinated against it, leaving them susceptible to severe illness or death if Omicron begins to spread.”

While the current wave is expected to be comparatively milder, XBB has the potential to wreak more havoc in China than it did elsewhere for exactly these reasons. COVID-appropriate behaviour — mask mandates and social distancing — can lessen the impact. 

The expected rise in cases also coincides with China’s investment in variant-specific vaccines.

The country’s drug regulator has reportedly given preliminary approval to two new vaccines targeting the XBB variant, while another three or four “will be cleared soon”, Nanshan said. “We can lead the pack internationally in developing more effective vaccines.” 

The impacts of these moves are already being reflected in the market, with a gauge tracking 55 COVID-19 treatment-related stocks listed in China rising 2.8 per cent, the most since mid-December, the newspaper South China Morning Post reported, citing financial information website Eastmoney

Hybio Pharmaceutical, Guangdong Zhongsheng Pharmaceutical and Shandong Xinhua Pharmaceutical recorded the highest jump, preceded by a slump after the Zero COVID policy was lifted. China has administered a total of 3.49 billion doses of COVID-19 vaccines as of February 2023, showed government data. 

Of these, around 1.31 billion people had received a dose and 1.27 billion people two doses, accounting for 92.95 per cent and 90.58 per cent of the total population, respectively.

China’s focus on variant-specific vaccines is in line with the WHO’s latest statement from May 18 where it argued, “notwithstanding the protection against severe disease, protection against symptomatic disease is limited and less durable (from index virus vaccines). New formulations of COVID-19 vaccines are needed to improve protection against symptomatic disease.” 

In conclusion, the global health body recommended “moving away from the inclusion of the index virus in future formulations of COVID-19 vaccines.” 

It cites a host of reasons for this suggestion, chief among which are the following; the index virus is no longer circulating and including it in variant-specific vaccines reduces the concentration of the new target antigen(s).

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