In the present case of the novel coronavirus, two questions that are fundamental to furthering our understanding of its epidemiology are:
- What is the course of the disease in healthy people without underlying health conditions?
- How does the virus spread in a group of people?
The World Health Organization estimates that 80% of all infections with SARS-CoV-2 may show no or only mild symptoms, similar to a common cold[1]. These cases are usually not reported to health authorities unless they are detected in a controlled environment. In the Heinsberg study of the University of Bonn – investigating in detail one of the early hotspots of Covid-19 in Germany – it was found that the total number of infections was five times higher than those recorded by the authorities, i.e. an unreported figure of 80%[2].
According to the German Robert Koch Institute, most patients with Covid-19 diseases (67% as of 2020-04-29 are between 15 and 59 years old [3]. This value corresponds well with the extensive data from Iceland [4], according to which almost 75% of the infections occur in the age group 18 – 69 years:
According to our extensive research, people of this age are severely underrepresented in existing studies on Covid-19, although as the group with the strongest social interactions, they might have a tremendous effect in spreading Covid-19.
Our approach
On one given date, a defined population gets in contact with the virus in a natural way. Then, this population stays isolated from other people for a defined period of time (14 – 21 days), assuming that none of the participants will be infectious afterwards.
The preconditions and the daily status of each participant are noted. Factors for susceptibility to be observed are e.g.:
- medical conditions
- previous infections
- lifestyle
- stress level and specific stressors
- sporting activities
- nutrition
- health supplements
Outcome:
- We can measure the incubation time (the number of days until symptoms occur in the participants).
- We can measure how many of the population will be infected at all.
- We can see what symptoms will occur under which preconditions.
- We can evaluate which natural measures work best to minimize symptoms.
- We can measure antibodies/immunity created in the end of the time of group isolation.
- There is a possibility to contact the participants again after a given time to re-assess their immunity.
The floating research center
To simulate real life which is typical for the age group 20 – 60 years, a setting with close social contact is needed, as in a village, while all relevant factors for infection can be controlled.
From a scientific point of view, a ship offers ideal conditions for infectiological and epidemiological studies:
- A ship is a self-sufficient unit, which is easily separable and can sustain its inhabitants for the duration of the study.
- On a ship, epidemiological investigations can be carried out on groups of several hundred people.
- Due to its mobility, a ship can be positioned in such a way that environmental influences such as air pollution do not affect the quality of data collected in the study.
- For risk management purposes, a ship offers the possibility of being transferred to an isolated port in case of an emergency.
- Based on the current quarantine regulations for Covid-19, a two to three week research trip should be sufficient to achieve the study’s aims.
This is where cooperation with the cruise lines, which are currently forced to let their ships lie unused due to the shutdown of tourism activities worldwide, would come in handy. In view of the advanced age of the typical guests on board, cruise ships in particular already have good medical equipment available.
Example: MS HANSEATIC nature
These expedition cruise ship for max. 230 passengers represents for us a suitable type of study environment, framing the Corona studies as joyful retreats which promote resilience and well-being, while offering the safety of a modern, well-equipped ship’s hospital [5]:
Image by Gerd Fahrenhorst via Wikipedia
MS HANSEATIC nature and the sister vessel MS HANSEATIC inspiration are currently berthed in Hamburg (AIS per 2020-05-06) [6].
The method
The study is based on the concept of Controlled Human Infections, used in the development of vaccines [7].
“Controlled Human Infections give a unique insight in the development of infections in people. We will be able to better combat infections with this know-how.”
Prof. Leo Visser, Leiden University Medical Center [8]
Risk management
In view of the fact that large parts of the population will be naturally exposed to SARS-CoV-2 as a result of the current pandemic, well designed studies would not approve misgivings about their ethical responsibility [9].
“We can learn so much from controlled infections in people. As long as we keep on being cautious, the safety of the volunteers is being guaranteed.”
Dr. Meta Roestenberg, Leiden University Medical Center [8]
For risk estimation we use the extensive data from Iceland [4]. Regarding their life conditions Iceland’s population can be assumed as healthy [10] so that these data seem suitable for reliable calculations of the studies’ risk.
Per 2020-04-24 on Iceland only 1 person under 60 years died of totally 1,311 infected persons in the age of 18 – 59 – i.e. a lethality of 0.076%.
Medical per-examination of the volunteers could further minimize the risk of underlying conditions causing severe courses of disease. New findings, such as the accumulation of thromboses and pulmonary embolisms in severe cases of Covid-19 [11] and their prophylactic treatment with heparin [12], will of course be incorporated into our safety measures for study participants.
References:
[1] WHO 17.3.2020: Q&A: Similarities and differences – COVID-19 and influenza
https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/q-a-similarities-and-differences-covid-19-and-influenza
[2] Universität Bonn 4.5.2020: Ergebnisse der „Heinsberg-Studie“ veröffentlicht
https://www.uni-bonn.de/neues/111-2020
[3] Täglicher Lagebericht des RKI zur Coronavirus-Krankheit-2019 vom 29.4.2020:
https://www.rki.de/DE/Content/InfAZ/N/Neuartiges_Coronavirus/Situationsberichte/2020-04-29-de.pdf
[4] COVID-19 in Iceland – Statistics:
https://covid.is/data
[5] Hapag Lloyd Cruises – The new expedition class – On board:
https://www.hl-cruises.de/schiffe/hanseatic-nature-hanseatic-inspiration-hanseatic-spirit/an-bord
[6] MarineTraffic – leading provider of ship tracking: https://marinetraffic.com
[7] Christopher Chiu: The role of Controlled Human Infection Models in licensure of vaccines:
https://www.who.int/immunization/research/meetings_workshops/10_Chiu_MacLennan_CHIMsLicensure.pdf
[8] Leiden University Medical Center – Controlled Human Infections
https://campagne.lumc.nl/controlled-human-infections1
[9] Shah et. al 2020-05-07: Ethics of controlled human infection to study COVID-19
https://science.sciencemag.org/content/early/2020/05/06/science.abc1076
[10] OECD Better Life Index
http://www.oecdbetterlifeindex.org/countries/iceland/
[11] Wichmann et al 2020-05-06: Autopsy Findings and Venous Thromboembolism in Patients With COVID-19
https://annals.org/aim/fullarticle/2765934/autopsy-findings-venous-thromboembolism-patients-covid-19-prospective-cohort-study
[12] Pilatus Today 2020-04-23: Forscher macht Hoffnung im Kampf gegen Covid-19
https://www.pilatustoday.ch/schweiz/forscher-macht-hoffnung-im-kampf-gegen-covid-19-137703683
