Indonesian Study Finds Coronavirus Antibodies in 85% of Population

A survey published by the University of Indonesia on Thursday found coronavirus antibodies in over 85 percent of the population, due to both vaccinations and natural immunity due to viral infections.

Researchers credited this surprisingly high level of antibodies for the relatively low number of cases and fatalities during Indonesia’s delta variant wave over the summer, and the absence of an omicron surge today.

The study, conducted from October to December, included 22,000 participants. Indonesia’s population of 270 million is only about 42 percent vaccinated, so finding antibodies in 85% of the survey subjects was unexpected.

Indonesia peaked at about 50,000 infections a day during the summer delta wave, but is currently logging only a few hundred a day. About 250 cases of the highly infectious Omicron variant have been documented, most of them imported from other countries.

Indonesian epidemiologist Pandu Riono took the survey results as evidence for the superiority of “hybrid immunity,” which ostensibly develops in people who have been vaccinated and also develop natural antibodies from exposure to Chinese coronavirus.

A survey of Indonesia’s capital city Jakarta published over the summer found coronavirus antibodies in 44 percent of the population, a much higher portion than could be explained by either vaccination or documented infections. Jakarta was about 18 percent vaccinated at the time. 

Indonesia was highly dependent upon dubious Chinese vaccines until last summer, when it began offering booster shots of Moderna’s mRNA vaccine. Studies conducted beyond the reach of the Chinese Communist Party found China’s Sinovac vaccine produced only about ten percent as many antibodies as mRNA products.

Researchers originally thought it would be difficult for a city with highly mobile citizens like Jakarta to develop “herd immunity,” a high level of antibodies developed naturally through exposure to the virus. Epidemiologists said a lingering question from the new study showing 85 percent antibody levels is how long the antibodies will last, and whether the protection afforded by natural immunity or vaccination proves to be more durable.