If lockdown is lifted end of April, coronavirus will 'rebound': German Study
A group of scientists at the University of Erlangen-Nurnberg in Germany said that if lockdowns were lifted by the end of April, the coronavirus would simply rebound.
They expect that “repetitive short-term lockdowns and hygienic measures (such as wearing masks and gloves)” need to be in place for the next two or three years if a vaccination is not found before that.
Their research paper, which was published journal bioRxiv.org on Tuesday, is based on published coronavirus data for Germany.
Their model assumes a "reproduction number" of three, meaning that on average, one infected person can spread the virus to three other persons. However, if the infected persons get symptomatic and stay at home, their contact rate is halved such that they only can infect half the number of persons. If they are isolated in a hospital, the scientists assume that they infect on average one additional person, for example in their family, before they are isolated.
They investigated the potential effects of a combination of measures such as continuation of hygienic constraints after leaving lockdown, isolation of infectious persons, repeated and adaptive short-term contact reductions and also large-scale use of antibody tests in order to know who can be assumed to be immune and participate at public life without constraints.
They concluded that “without enacting interventions such as the lockdown in March 2020, the disease would cause significant overload of the health system with many deaths expected. This is in agreement with the findings of other COVID-19 models.”
“If the lockdown would just be released after 4 weeks in April and a return takes place to the status before lockdown, the disease can be expected to rebound just with a slight delay corresponding to the time of the lockdown, meaning that a little time has been gained in order to prepare the health system better but with the same potentially large number of deaths.”
They added that putting “hygienic measures” in place after lockdown would create a “slight mitigation” but would not be sufficient to defeat the disease.
The scientists expect that “repetitive short-term lockdowns and hygienic measures need to be in place for the next two or three years until herd immunity can be obtained (if vaccination is not available before).”
Herd immunity refers to a situation where enough people in a population have immunity to an infection to be able to effectively stop that disease from spreading. It doesn't matter whether the immunity comes from vaccination, or from people having had the disease. The crucial thing is that they are immune.
“When about 70 percent of the population have been infected and recovered, the chances of outbreaks of the disease become much less because most people are resistant to infection,” said Martin Hibberd, a professor of Emerging Infectious Disease at the London School of Hygiene and Tropical Medicine.
“This is called herd immunity.”