What you need to know:
- Attempts to peer into the future of the pandemic have seen scientists end up with big misses.
- Models are not meant to predict the truth but to show what might be.
Coronavirus has infected over 31 million people out of which about one million have died. Since the outbreak was declared a pandemic by the World Health Organization on March 11, scientists began to paint pictures of how much it would spread and how many people it would kill.
Comparing some of the projections with the actual cases and deaths recorded globally and in many parts of the world, it is clear that few experts knew the numbers would turn out in the exact way they did so far.
For example, by June 16, Australia had recorded 737 cases and 102 deaths. Earlier, in March, the government had announced it was preparing for between 50,000 and 150,000 deaths.
Six months on, Australia, with 27,000 cases and 869 deaths, has turned out a lot better than the picture forecasted.
Explaining the disparity to The Guardian, epidemiologist Gideon Meyerowitz-Katz said that “modelling cannot ever capture the truth, because that is not its purpose”.
The scientist and writer held that models are not meant to predict the truth but to show what might be. That many projections have been way off the mark has been attributed to the fact that the coronavirus is new and therefore scientists are on a steep learning curve. Also, some projections have adopted models without considering the peculiar differences in population characteristics or government interventions.
Dr Anthony Fauci, the leading US government infectious disease expert, has put it even more aptly: “I just don’t think that we really need to make a projection, when it’s such a moving target that you can so easily be wrong and mislead people.”
However, that advice has not stopped experts, including Dr Fauci himself, from peering into the future.
The government had predicted that some 10,000 people would be infected by the virus in the first month. However, only 197 infections were reported. The scientists at the University of Nairobi’s Institute of Clinical Research and Kenya Medical Research Institute also projected between 300 and 400 deaths, compared with the 8 eventually reported.
Again on May 30, when Kenya had 1,888 cases and 63 deaths, the Ministry of Health Acting Director General said that according to the model the government was using, 4,000 to 5,000 people would have been infected and 160 to 180 people killed by Covid-19 by August.
In July, the ministry directed the Kenya Medical Supplies Authority (Kemsa) to procure 100,000 body bags, in preparation for a “worst-case scenario” as the country was headed towards the peak. Then, it was projected that, at worst, 450,000 people would be infected with the virus, leading to 45,000 deaths before the curve flattened.
But there were 34,201 cases and 205 deaths by the end of August, now seen as the peak of the first wave, rendering the two forecasts other big misses.
In September, the ministry and the Kenya Medical Research Institute (Kemri) scientists project that less than 1,000 people will have died of Covid-19 in the country by the end of December.
The government had projected 5,000 deaths by the end of the year, said Dr Amoth on Thursday, adding that it is the interventions put in place that will see the number remain at under 1,000.
On March 29, slightly over two months after the first case of coronavirus was reported in the US, Dr Fauci said that the coronavirus could kill 100,000 to 200,000 people in the country. By then, the country had confirmed about 125,000 cases of Covid-19.
The projection by Dr Fauci sounded seriously embellished and was disregarded by many, despite the fact that it came from a medical professional of such high stature.
President Donald Trump and many Americans continued to play down the potential danger posed by the virus. The president and Governor Andrew Cuomo chose to issue an advisory rather than declare a quarantine in the state of New York. Mr Trump even hinted that parts of the US could reopen by Easter, a statement opposed by public health officials, as well as state and local authorities, saying that things could only get worse before they got better.
Mr Trump’s defiance and disregard of professional advice have been the hallmark of the arguably weak response to Covid-19 in the US.
Today, the good doctor has been more than vindicated, as the virus had killed over 207,000 people from over seven million infections by September 25. As daily deaths remain over 1,000, the death toll is projected to continue to swell in the months before a vaccine becomes available to every American.
On April 26, the government projected that 27.5 million people would have tested positive for Covid-19 in the country by August 15. However, it turned out that only 2.6 million tested positive by then.
Another big miss was a theoretical model published on Medrxiv projecting the near end of the epidemic to be in the middle of July 2020. According to the article ‘CoViD-19 Epidemic in India and Projections: Is Relief in Sight?’ new daily cases were expected to peak at about 3,300 in the fourth week of May. However, the fourth week of May started with 2,394 cases in a day and ended with 8,336. The model also predicted that the number of cumulative cases would not decrease but instead plateau around the first week of June, with only less than 100 new cases per day. On the contrary, June saw a gradual rise in daily cases to as high as 19,906. India did not experience a plateau until after September 11 when daily cases peaked at 9,757.
In March, the government disagreed with a projection by a team of world-leading disease data analysts that showed that the UK would become the country worst hit by the pandemic in Europe, accounting for more than 40 per cent of total deaths across the continent. At least 66,000 would have died by August, a time daily deaths would have peaked at 3,000, according to the Institute for Health Metrics and Evaluation (IHME), responsible for the Global Burden of Disease study.
The country was also projected to record more Covid-19 deaths than Italy, Spain, France and Germany combined, by August.
The modelling relied on three factors: what had happened in other countries that were ahead in their epidemics, such as Italy and Spain; what had happened so far in the UK and when physical distancing measures were put in place.
A few scientists and institutions whose modelling the government relied on disagreed, saying the model did not match the then UK situation. They predicted that the pandemic would claim 260,000 lives in the UK by the time it ended, with no restrictions on movement. That, they said, could drop to 20,000 with a lockdown strategy in place.
Today, about 42,000 people have died in the UK despite the lockdown measures. Analysts think that deaths could have been minimised had the government not wasted time toying with the idea of “herd immunity” and instead began promoting physical distancing measures in good time.
But despite coming in late, physical distancing seems to have had a great impact, at least to the extent of upsetting the 66,000 deaths forecasted by IHME. A lot fewer people (41,589) had died by August 31. And while the UK has the highest number of deaths in Europe as predicted by IHME, this is only 19 per cent of the continent’s total, less than a half of the 40 per cent predicted. Also, daily deaths peaked at 1,224 in April, less than a half of the 1,500 projected.
On April 6, an official projection by Brazil’s Sao Paulo state, the epicentre of the coronavirus outbreak in Latin America, announced that it expected 111,000 deaths in the next six months. It does not appear like that many people will have died of Covid-19 by October 6 because as at September 21, Sao Paulo has recorded 33,952 deaths, according to the New York Times coronavirus tracker, less than a third of the projected figure. Daily new cases have also been dropping in the past few weeks. The state reported between 1,000 and 1,500 daily in the past seven days, down from 1,400 to 2,000 in the previous week.
On May 26, the WHO regional director for the Americas Dr Carissa Etienne said the organisation was concerned about worsening situation in Brazil. She pointed to the IHME model showing that “daily deaths are growing exponentially, forecasting a peak of about 1,020 daily deaths by June 22, 2020. By August 1, 2020, a total of 88,300 deaths are projected.”
Some 93,563 people had died in Brazil by August 1, only 5,000 more than what was projected. However, the daily deaths peaked at 1,595 and over a month later than predicted.