(Bloomberg) -- As its Covid Zero lockdowns have become harsher and more economically disruptive, China has repeatedly invoked the specter of millions of vulnerable elderly people dying as justification for its strict virus approach.

What remains unaddressed is why, with an abundant supply of homegrown vaccines and vast enforcement power, so many of China’s over-60s remain unvaccinated more than a year after shots became available.

Read more: China’s Covid ‘Triumph’ Lies in Vaccines, Drugs, Mild Variants

China is now paying a price for this vulnerability, with its economy struggling under the weight of chaotic lockdowns and increasingly unpredictable measures aimed at snuffing out all cases and shielding the community.

About 216 million Chinese aged 60 and older have been fully vaccinated, almost 82% of that age group, according to National Health Commission data from Friday. And 164 million have received boosters. But the statistics get worse the older you get, with officials saying in March that only about 50% of people aged 80 and over had been vaccinated.

What’s unusual is China’s reluctance to compel the segment of the population most susceptible to bad outcomes from Covid to get inoculated. It stands in contrast to authorities’ strict enforcement of mass lockdowns and testing, and the pressure put on students and employees at state-owned enterprises to get vaccinated. China is also no stranger to invasive policies, like the one-child policy it had in place for more than three decades until abolishing it in 2016.

“China really missed an opportunity in the last two years,” said Feng Wang, a sociology professor at the University of California, Irvine, who has done research on demographic change in China. “In most other countries they started with the elderly, they gave priority to the elderly to get vaccinated. It was only in China the effort was put on vaccinating the younger population.”

The disparity has its root at the start of the vaccine development process. 

Locally developed shots, the only inoculations available in China, didn’t focus significantly on the effect on seniors in the clinical trial phase. It meant relatively little was known about the efficacy and risk of side effects for elderly people, some of whom have complicated health conditions, and led to concern from officials about the potential health risks, according to Wang. Some doctors actively counseled elderly people with other conditions from getting shots.

No Urgency

China’s early Covid success also contributed to the lack of urgency, with officials largely keeping the virus out through much of 2020 and the first half of last year after quelling the initial outbreak in Wuhan. The lack of a clear and visible threat meant vaccinating seniors, who are less likely to work or utilize public spaces like schools and shopping malls, was less of an imperative.

Read more: Xi Moves to Silence Covid Zero Critics in Sign of Brewing Tumult

And despite the government’s control of information and China’s closed internet, the nation and its elderly also weren’t immune to the anti-vaccine propaganda that stalled Covid shot rollouts from Europe to the U.S., according to Xi Chen, an associate professor of public health at Yale University.

When more contagious variants started to scale China’s stringent pandemic defenses, the ramifications of the country’s lagging elderly inoculation rate started to become clear. In Hong Kong, which has also followed the Covid Zero strategy, unvaccinated seniors ended up accounting for the majority of fatalities in what became the world’s deadliest outbreak.

In Shanghai, too, which is slowly emerging from a brutal six-week lockdown, unvaccinated older people have made up the bulk of deaths. 

Read more: China’s Low Elderly Vaccination Rate Shows Key Vulnerability

For those over 80, China is seeing little difference in the death rate for those who got the original strain of the virus in Wuhan and those who are now getting omicron, which has proven milder in many parts of the world at least partially because of the rollout of vaccines. Even with a recent vaccination push in March, an unchecked omicron wave would still cause about 1.6 million deaths, according researchers at Shanghai’s Fudan University.

Read more: China Risks Virus ‘Tsunami’ If Covid Zero Abandoned: Study

Fatalities may fall to a level that’s comparable with seasonal influenza if the elderly vaccination rate gets to 97% and antivirals are used to treat at least half of all symptomatic infections, the Fudan scientists said.

Until then, China will likely continue to rely on lockdowns and mass testing to keep stamping out virus flareups.

While the measures are harsh -- Shanghai’s residents have endured periods food shortages as drones hovered above apartment blocks monitoring for lockdown breakers -- the government may still view those restrictions as more acceptable than forcing the elderly to get vaccinated, according to Stuart Gietel-Basten, a professor of social science and public policy at the Hong Kong University of Science and Technology’s Institute for Emerging Market Studies.

“Locking people up and sending drones around is very different to strapping people down and putting a needle in their arms,” he said.

Moreover, China’s main priority ahead of a Communist Party congress later this year -- where Xi is expected to secure an unprecedented third term -- is to maintain stability, rather than negotiate an exit from the pandemic. China’s top leaders have repeatedly warned against questioning the Covid Zero strategy, which has led to a much lower overall death rate than countries like the U.S., making it a key part of the Party and Xi’s triumphalist rhetoric.

Read more: Six Indicators That Will Signal China Is Abandoning Covid Zero

Using China’s resources on vaccination rather than testing won’t help officials achieve that short-term political goal, said Yanzhong Huang, senior fellow for global health at the Council on Foreign Relations.

Cash Incentives

“It doesn’t make sense to start promoting vaccination among the elderly or the general population, because it takes time for vaccination to take effect,” he said. “‘Zero Covid’ provides a short-term, immediate solution to the problem. The fundamental problem is the tension between the ‘Zero Covid’ policy and the mitigation approach that would prioritize the at-risk population, especially the elderly.”

Data Monday showed industrial output and consumer spending sliding to the worst levels since the pandemic began, while the jobless rate climbed.

Read more: China’s Economic Activity Collapses Under Xi’s Covid Zero Policy

For now, authorities are rolling out incentives to try and bolster elderly vaccination rates. In Beijing, officials hoping to convince seniors to get inoculated are giving away cooking oil, eggs, milk and other groceries. In some parts of the capital, older people who agree to get their first shot get cash rewards of as much as 1,000 yuan ($150).

On a recent afternoon, two health workers spruiked vaccinations in eastern Beijing’s Honglingjin Park, a popular spot for seniors to gather with friends. A woman surnamed Chen, 72, said she agreed to get her first two doses last year after pressure from her daughter, but had held off on a third because she felt safe in Beijing.

“I didn’t feel like I needed it,” said Chen. She’s now, however, consented to get a booster as an outbreak in the capital spurs increasing restrictions. “It’s a little scary, especially after what happened in Shanghai.”

©2022 Bloomberg L.P.