In these first weeks of 2023, the world seems to be going through a collective déjà vu of events in early 2020, when the pandemic was just unfolding. Like then, there is once again a major outbreak of Covid-19 in mainland China. Once again, many countries are imposing travel restrictions on Chinese travelers. And once again, fears of new Omicron super variants are circulating widely in social and mainstream media.
These superficial similarities aside, what does the Omicron outbreak in China mean for the region and the world?
The culminant iteration of viral evolution in 2021 was Omicron, a variant so different from its predecessors that it sparked off large waves around the world including Hong Kong. Omicron enjoyed widespread circulation globally through most of 2022 in the form of its sequential subvariants: BA.1, BA.2, and BA.4/BA.5. Of late, Omicron has splintered into myriads of subvariants vying for global dominance. The most “successful” (e.g., BA.2.75.2, XBB.1.5, BQ.1.1) share a common attribute in that they are increasingly able to evade antibodies generated from previous Omicron infections or first-generation vaccines.
The silver lining is that Omicron infections are often mild due to a combination of inherently reduced transmissibility and prior immunological experience in infected patients. Therefore, in places with high levels of hybrid immunity (arising from combinations of infections and vaccinations), Covid-19’s toll on public health is much diminished when compared to the nadir of the pandemic. Updated bivalent mRNA vaccine boosters encoding BA.4/BA.5 are further bolstering immunity in individuals most at risk of severe disease, i.e., the elderly and those with chronic medical conditions. Availability of antivirals for early infection can further relieve pressure on healthcare systems during large waves of Omicron. Humanity has developed tools to live effectively with Covid-19, which itself is well adapted to us and will continue to circulate as another seasonal respiratory virus.
The situation in mainland China, however, sharply contrasts with that of the rest of the world. China had adhered to a strict zero-Covid policy for the best part of the last three years. This policy relied on strict border controls, centralized isolation and quarantine, mass testing, surveillance, and a low threshold for lockdowns to contain Covid-19 at very low levels even as other parts of the world were being engulfed by sequential waves.