How many people are Covid-19 immune? Diamond Princess case study
Diamond Princess was the first quarantined cruise ship due to the corona COVID-19 virus. All of 3710 people on board were trapped at Diamond Princess for at least 20 days. Virus was spreading rapidly due to the low hygiene and defective coronavirus counter-measures on the ship. At some point, virus stopped spreading exponentially. Only 19% of people onboard were infected. The rest may have shown no symptoms or have been totally immune.
This study compares real cases vs. exponential models (24% and 33% new cases daily).

We expect that a significant share of the population may be immune to coronavirus and even do not spread the disease at all.

New Strategy with New Hope
We expect that a significant share of the population may be immune to coronavirus and even do not spread the disease at all. These immune people are precious asset on how to stop and cure coronavirus.
The main questions are:
- What’s the rate of the population which will show no symptoms, however, will or may spread a disease?
- What’s the rate of population, which is immune and do not spread disease?
- What are the methods for testing and how to find the immune population?
This case study with data is freely available as open data on
Statistics:
Name of statistics | Value |
Start of quarantine | 1.2.2020 |
End of quarantine | 20.2.2020 |
Ship empty on | 27.2.2020 |
Last data | 29.2.2020 |
People quarantined onboard | 3710 |
Guests onboard | 2666 |
Crew onboard | 1045 |
People infected | 705 |
Share of infected people | 19,00% |
Share of uninfected / No symptoms / Immune | 81,00% |
Number of deceased people | 6 |
Death rate during the period of monitoring | 0,85% |
Case study length (days) (All people onboard) | 20 |
Case study length (days) (Ship empty with no new data) | 27 |

Cruise ship timetable
Diamond Princess cruise ship sailing from Yokohama (Tokyo) to Hong Kong and back
Yokohama – Tokyo 20.1.2020
Hong Kong 25.1.2020
Again in Yokohama (Tokyo) – 4.2.2020
Quarantined ship after 1.2.2020
End of quarantine on 20.2.2020
Ship empty on 27.2.2020
Start
Princess Cruises confirms that a guest from Hong Kong who traveled for five days on Diamond Princess from Yokohama (Tokyo) on January 20, and disembarked in Hong Kong on January 25, tested positive for coronavirus on February 1, six days after leaving the ship. He was not seen in the ship’s medical center for any reported illnesses during the voyage. The guest is currently admitted to a local hospital and reported to be in a stable condition.
End
Approximately six hundred guests onboard Diamond Princess were the first to be cleared by the Japanese Ministry of Health and released to disembark the ship yesterday. These guests — all being cleared after a COVID-19 test by the Japanese Ministry of Health — were met in the Yokohama cruise terminal by Jan Swartz, President of Princess Cruises. Several hundred other guests are expected to be cleared today by health officials.
Princess Cruises can confirm that the disembarkation of all the guests aboard Diamond Princess is complete. Specialists from the Princess Care Team and Family Assistance programs remain available to both guests and team members.
Question for you:
How you can quarantine people on the ship? You can lock them in their cabins. All 2666 guests onboard. How many viruses can be transferred via air, climatization, food, water, or even via coronavirus testing?
How many viruses may spread, when 1045 crew people are together in same place? The crew needs to care for all the guests on the ship. The crew was not quarantined and divided into sick, possibly sick and healthy.
Are you still sure, that all the people in Cruise Ship were really quarantined? What is your estimate? How many of 2666 guests and 1045 crew were in contact with COVID-19 coronavirus? The official share of infected people onboard was just 19%. Where is the rest?
About Failed Diamond Princess Cruise Ship quarantine
page with video:
https://edition.cnn.com/2020/03/24/us/diamond-princess-cruise-ship-asymptomatic-tests/index.html
Sources
Source of Data:
WHO Official reports & News
https://www.who.int/emergencies/diseases/novel-coronavirus-2019/situation-reports
Source of news:
https://www.princess.com/news/notices_and_advisories/notices/diamond-princess-update.html
This study available on link:
This study is free to share and use in Press & Media with publishing original link to study.
Comment (1)
About Failed Diamond Princess Cruise Ship quarantine
https://www.businessinsider.com/how-diamond-princess-cruise-ship-coronavirus-quarantine-went-wrong-2020-2
Question for you:
How you can quarantine people on the ship? You can lock them in their cabins. All 2666 guests onboard. How many viruses can be transferred via air, climatization, food, water, or even via coronavirus testing?
How many viruses may spread, when 1045 crew people are together in same place? The crew needs to care for all the guests on the ship. The crew was not quarantined and divided into sick, possibly sick and healthy.
Are you still sure, that all the people in Cruise Ship were really quarantined? What is your estimate? How many of 2666 guests and 1045 crew were in contact with COVID-19 coronavirus? The official share of infected people onboard was just 19%. Where is the rest?
Comments are closed.