Marc Lipsitch, a professor of epidemiology at Harvard University, said earlier this month that between 40 to 70 percent of the population around the world will be infected with the coronavirus that causes Covid-19, a figure that was widely repeated and reported on when he first made his statement.
Dr Lipsitch has also said that ultimately, the disease would not be containable, which is one of the first steps taken during an outbreak of a contagious disease.
However he said that despite the large percentage of people affected by the coronavirus, the Harvard epidemiologist assured that even then it is not at all a reason for panic because it does not mean people will come down with a severe form of the illness.
On the contrary, he said, “It’s likely that many will have mild disease, or may be asymptomatic.” The same situation can be seen with the flu, with around 14 percent of people who are positive for the flu showing no symptoms.
Furthermore, a majority of the cases of coronavirus will get better even without medical care, similar, again, to the flu.
The biggest risk of Covid-19 continues to be to older individuals and those with existing health conditions.
Dr Lipsitch also wrote then on Twitter that efforts at containment are necessary, as it gives time for preparation, gathering supplies, vaccine development, and observing trends in people positive for the virus. Containment measures may include, he said, travel restrictions.
But should a community spread arise, containment would have to give way to mitigation efforts. He wrote, “We must make sure that restrictions on travel, quarantine, and the like do not outlast their usefulness — they are costly to individuals, families, and economies and should only be used as long as justified.
If there is widespread community transmission driven importantly by mild or asymptomatic cases — still a big if — then it will be like flu and control measures targeting cases should be relaxed in favor of general social distancing to reduce contacts (sic) in general.”
at which point will have to shift to mitigation rather than containment, and we must make sure that restrictions on travel, quarantine, and the like do not outlast their usefulness — they are costly to individuals, families and economies and shd only be used as long as justified
— Marc Lipsitch (@mlipsitch) February 14, 2020
On Wednesday (Feb 26), Dr Lipstch updated his prediction concerning the spread of Covid-19, affirming that there seems to be a pandemic. “Increased confidence in claims: Since I wrote this, large numbers of cases have appeared in new countries (Iran, Italy) or increased dramatically (S. Korea), increasing the evidence that this will become or already is a pandemic.”
Moreover, he has also revised his opinion on how many people worldwide would be affected.
Modified in light of evolving evidence: 1) The 40-70% figure strictly speaking is only a sensible prediction for adults. Detected infections in kids to date are rare. Can happen, but rare. Still unclear if they are rarely infected or just so mild that they are rarely detected.
— Marc Lipsitch (@mlipsitch) February 25, 2020
“Modified in light of evolving evidence: 1) The 40-70% figure strictly speaking is only a sensible prediction for adults. Detected infections in kids to date are rare. Can happen, but rare. Still unclear if they are rarely infected or just so mild that they are rarely detected. Until we know, safest to reserve the predictions for adults.”
He also lauded China’s control measures for successfully reducing transmission rates. And while these strict measures can probably not be sustained for the period in which it takes to develop a vaccine, around one year, “even more moderate” controls “if effective could reduce incidence considerably.”
Therefore, he adjusted his earlier predicted figure for infection.
So in light of @WHO's statements of the last days that these measures have been super effective, this seems the most likely way the 40% lower bound could be too high. I very much hope this is the case, but we do need to think about what controls like that for months mean.
— Marc Lipsitch (@mlipsitch) February 25, 2020
“So in light of @WHO ‘s statements of the last days that these measures have been super effective, this seems the most likely way the 40% lower bound could be too high. I very much hope this is the case, but we do need to think about what controls like that for months mean.
Summary: Should have said 40-70% of adults in a situation without effective controls.” —/TISG