Trying to Solve a Covid Mystery: Africa’s Low Death Rates

While health surveillance is weak, he acknowledged, Sierra Leoneans have the recent, terrible experience of Ebola, which killed 4,000 people here in 2014-16. Since then, he said, citizens have been on alert for an infectious agent that could be killing people in their communities. They would not continue to pack into events if that were the case, he said.

Dr. Salim Abdool Karim, who is on the African Centers for Disease Control and Prevention Covid task force and who was part of the research team tracking excess deaths in South Africa, believes the death toll continentwide is probably consistent with that of his country. There is simply no reason that Gambians or Ethiopians would be less vulnerable to Covid than South Africans, he said.

But he also said it was clear that large numbers of people were not turning up in the hospital with respiratory distress. The young population is clearly a key factor, he said, while some older people who die of strokes and other Covid-induced causes are not being identified as coronavirus deaths. Many are not making it to the hospital at all, and their deaths are not registered. But others are not falling ill at rates seen elsewhere, and that’s a mystery that needs unraveling.

“It’s hugely relevant to things as basic as vaccine development and treatment,” said Dr. Prabhat Jha, who heads the Centre for Global Health Research in Toronto and is leading work to analyze causes of death in Sierra Leone.

Researchers working with Dr. Jha are using novel methods — such as looking for any increase in revenue from obituaries at radio stations in Sierra Leonean towns over the past two years — to try to see if deaths could have risen unnoticed, but he said it was clear there had been no tide of desperately sick people.

Some organizations working on the Covid vaccination effort say the lower rates of illness and death should be driving a rethinking of policy. John Johnson, vaccination adviser for Doctors Without Borders, said that vaccinating 70 percent of Africans made sense a year ago when it seemed like vaccines might provide long-term immunity and make it possible to end Covid-19 transmission. But now that it’s clear that protection wanes, collective immunity no longer looks achievable. And so an immunization strategy that focuses on protecting just the most vulnerable would arguably be a better use of resources in a place such as Sierra Leone.