China’s fight against the COVID-19 pandemic has taken a new turn, as researchers predict cycles of reinfection every six months in the absence of COVID-19 restrictions and the dominance of highly infectious variants. Although not unexpected, these rolling waves of infections pose an inherent risk of new and potentially more severe variants emerging, posing further challenges to containment efforts.
Ali Mokdad, an epidemiologist at the University of Washington’s Institute for Health Metrics and Evaluation, acknowledged in a report published in the journal that reinfection with the virus is inevitable. natureHowever, there is concern that a new variant may emerge that could rival the current variant in severity and surpass existing ones.
The current surge in China is largely attributable to a highly contagious subvariant of Omicron, known as XBB.1.5, which was first detected in India last August. Respiratory physician Zhong Nanshan warned that as many as 65 million people could be infected every week by the end of this month.
China has a high vaccination rate, with more than 90 percent of the population vaccinated. However, immunity is waning, and XBB has the ability to bypass the protection provided by vaccines and prior infections. While XBB has not yet resulted in a significant increase in hospitalizations and deaths, the sheer number of infections has put pressure on China’s healthcare system.
XBB variants have also caused quite a stir in other parts of the world, such as Singapore and America. This pattern is observed globally, but its effects are more pronounced in China due to its large population.
Cao Yunlong, an immunologist at Peking University, and his team Discover Antibodies raised against previous Omicron variants BA.5 and BF.7, which dominated the December wave in China, can provide about four months of protection against strains such as XBB1.
High transmissibility of XBB has been observed in previous COVID-19 surges around the world. It spread quickly and became a major variant faster than its predecessor.
The current wave is expected to last for months, compared with the previous wave, which saw more than 200 million infections in China within 20 days. This elongated wave has been attributed to differences in individual immune background, such as antibody levels. Waves that ebb and flow more gently will reduce the burden on the healthcare system.
The exact number of infections in this wave remains unclear because China no longer publicly reports the number of COVID-19 cases. However, estimates suggest that at least 30% of the population (over 400 million people) may become reinfected.
Experts emphasized the importance of having robust surveillance systems in place to detect emerging virus variants. The ongoing infection cycle requires vigilance, as the emergence of new variants with XBB-like characteristics could have serious consequences.
Additionally, tracking the evolution of the virus allows scientists to update booster vaccines accordingly. Chinese cities such as Beijing and Shanghai have launched quadrivalent COVID-19 booster shots designed to provide broad-spectrum protection against various coronavirus variants, including XBB.
China is also actively developing a vaccine specifically for XBB. While current vaccines are good at preventing severe disease and death, their ability to provide long-term protection from infection is limited. Vulnerable groups such as the elderly remain at risk of severe illness due to the risk of recurrent infection and the possibility of prolonged COVID.
Published by Medicaldaily.com