Epidemiologists at the University of Minnesota continue to do their research on Coronavirus COVID-19. They recently published a report in which they presented three possible scenarios for COVID-19. The scenarios presented by scientists resemble waves of varying degrees of strength. Each scenario can be implemented until 2022. It is expected that by this time a COVID-19 vaccine should appear to vaccinate hundreds of millions of people.
Scientists at the University of Minnesota guided by leading epidemiologist Michael Osterholm, recently published a report on how they see the future of Covid 19.
All the three COVID-19 pandemic scenarios agree on the following: there is almost no probability that the pandemic will end in 2020. The reason for this forecast is the same as when the virus has first appeared - the lack of immunity in 50% of the world’s population. Nowadays the world is far from this value, Dr. Osterholm, the head of the study, believes. According to his estimates, less than 5% of the world's population is insured against having the coronavirus again, since people received antibodies.
There are still a lot of unknowns in COVID-19. When scientists were first asked what could happen if the coronavirus is not restrained, only a week has passed since the quarantine beginning in Wuhan, China. At that time only 10000 cases of the disease occurred in the world, and in only one patient who visited Wuhan was identified the United States. But even then, scientists were unanimous: it will not be possible to stop the pandemic.
A person who has antibodies to COVID-19 can still be a carrier of coronavirus infection. According to experts, there are two classes of antibodies - immune cells produced in the human body as a result of its contact with the virus.
- IgM are produced at the very beginning of the disease, and their detection indicates a current infection, in which case a person can definitely be a COVID-19 carrier.
- IgGs appear later. It is believed that its presence indicates a past illness and emerging immunity. Nevertheless, there is evidence of the possibility of IgG owners to act as carriers of infection for a short time. It is also not known what level of antibodies can protect against infection and how long acquired immunity lasts.
Thus, the presence of a positive IgG test result does not give any benefits - absolutely everyone should use personal protective equipment during a pandemic: infected and uninfected, sick and already recovered from COVID-19.
Even in the presence of a new coronavirus infection typical symptoms, in some cases the test for COVID-19 may be negative. This may be due to the quality of the biological material collected, the sensitivity of the test system used, or the timing of the analysis - the virus may be detected at the beginning of the disease and may not be detected at later stages. At the same time, a general blood test may be within normal limits for mild forms of the disease, even if the virus is detected.”
Scenario one: at the right time for the tides and flows
In such a scenario, the Covid-19 wave will peak and fall, peak again and fall during the next two years. Peaks of the disease will be approximately half of the spring 2020 outbreak, with the highest “crests” of the wave coinciding with the peak of seasonal flu. These factors will vary, depending on random outbreaks and the inability to track new foci of decease before they erupt.
The probability of such wave surges is due to the consensus that the coronavirus COVID-19 has some seasonality and neither hot nor cold weather will destroy it. Biologist Martha Shocket of the University of California explains that scientists are unanimous that weather is unlikely to suppress the virus this summer, and we will have a large population of people susceptible to the coronavirus.
Although summer heat and moisture can kill the virus on the surface, there will still be a huge number of people who will transmit it to each other through coughing, runny nose and simple communication with each other. But there is good news. In the summer, virus transmission may decrease by 20%, Mark Lipsich, epidemiologist from Harvard, says. He helped colleagues from Minnesota develop a scenario for the possible spread of the coronavirus COVID-19.
In the summer, the number of cases of infection from Covid 19 "mini-waves" may decrease by more than 20%, scientists from the University of Minnesota concluded. This means that restaurants and beaches can be opened, but large gatherings of people in closed spaces will be banned, and people should voluntarily practice social distance. A mask and gloves will become the same familiar attribute as a mobile phone. When the wave subsides, people will feel more confident, sometimes giving up precautions. Everything will be going on until they are covered by the next wave of COVID-19 pandemic and they either gain herd immunity or wait for the vaccine.
Scenario Two: History Repeats
March 1918 brought the first moderate wave of Spanish flu. Cases of the disease went down, but six months later, in the autumn, there was an outbreak of the epidemic. More than 50 million people became victims of the flu. Small peaks followed in early 1919, and the pandemic finally ended. The 1957 and 1958 influenza pandemics, as well as the 2009 swine flu, had a similar picture. In this scenario, scientists suggest that mortality can reach hundreds of thousands of cases by early August 2020 with millions of deceased.
After this catastrophic second wave, the "sea" will be almost calm, and the number of cases will be only one fifth of what spring 2020 saw. In this scenario, instead of appearing in the form of waves during the year, Covid-19 will peak at the end of summer and fall, and then subside and show a small but constant number of deceased cases.
A steep peak and a long fall will have two reasons. Firstly, with a current moderate first wave and a giant second wave, which will peak in October 2020, so many people will be infected that the population is already approaching gaining collective immunity. At the same time, the second wave of COVID-19, according to Osterholm, "will completely destroy the global health care system."
Scenario Three: The Worst Groundhog Days
Outbreaks of the disease will continue in different cities and people will be simply trying to suppress them with varying degrees of success. The epidemiologist professor Osterholm calls this the “slow burn” scenario.
The foci of the disease continue to flare up here and there, however, they will be smaller than in the second scenario with its monstrous wave of infections. Therefore, more time is required for the formation of the collective immunity of the population. Local outbreaks will occur, which can be stronger in some places than in the other ones.
This is due, in particular, to the ability to conduct large-scale regular testing and track patients’ contacts. Not a single viral disease developed this way before, but this scenario cannot be ruled out in the situation with COVID-19.
- One of the reasons is biological: coronaviruses, as shown by four previous epidemics, have the dangerous art of continuing to circulate in nature and not disappear completely. SARS coronavirus in the early 2000s was an exception.
- The other reason is sociological: there are real concerns about the ability of society to withstand another economic blow, not to mention repeated ones. In the future, quarantine policies, at least in some cities and states, may turn out to be less stringent and therefore less effective than those introduced this spring. This is why future COVID-19 outbreaks will continue with incidence rates comparable to the current wave in this scenario.
But which of the three scenarios is most likely? Professor Osterholm of the University of Minnesota does not know the answer to this question. "This virus has its own schedule. But we will have difficult months ahead."
COVID-19: “tug of war” game
Under these conditions, the main thing for society will be what the epidemiologist Gabriel Lang of the University of Hong Kong called the tripartite “tug of war” game among the three competing factors: supporting low morbidity and mortality, preserving jobs and emotional well-being of people. If part of the “tug of war” game in public health is weakened, the waves will continue until the end of 2022.
