Will COVID-19 survivors develop immunity from future infections?

Question

For this question, assume that the virus does not mutate.

Can survivors be expected to develop immunity? Why or why not (what is the thought process)?

The CDC FAQ indicates that they do not know:

Q: Can people who recover from COVID-19 be infected again?

A: The immune response to COVID-19 is not yet understood. Patients with MERS-CoV infection are unlikely to be re-infected shortly after they recover, but it is not yet known whether similar immune protection will be observed for patients with COVID-19.

As good as CDC is, I would expect that there are other excellent institutions and individuals that have insight.

CLARIFICATION: a survivor for this discussion is an COVID 19 infected patient that survives the infection. My understanding is that there is no reason to believe that the uninfected would develop immunity.

UPDATE: COVID 19 mutant strains have been detected in the UK.

Answer 1

There is a study from Chinese scientists from Bejing on this question:
Reinfection could not occur in SARS-CoV-2 infected rhesus macaques

Combined with the follow-up virologic, radiological and pathological findings, the monkeys with re-exposure showed no recurrence of COVID-19, similarly to the infected monkey without rechallenge. Taken together, our results indicated that the primary SARS-CoV-2 infection could protect from subsequent exposures, which have the reference of prognosis of the disease and vital implications for vaccine design.

One has to state that with four monkeys the statistics is very low, though.

There is, however, also a risk for relapse and further mutations of the virus as already pointed out by brasscup and Alexei.

Answer 2

This article from the UK Independent is a fair round-up of differing opinions on whether contracting the virus conveys immunity: https://www.independent.co.uk/life-style/health-and-families/coronavirus-immunity-reinfection-get-covid-19-twice-sick-spread-relapse-a9400691.html There have been reports of patients getting reinfected following recovery. The most discussed occured this month. In Osaka, a tour bus operator in her 40s tested positive for COVID-19 for a second time. She was first diagnosed with coronavirus in late January and was discharged from hospital on February 1. But there is disagreement as to whether it is an entirely new infection or a relapse.

Answer 3

As of May 2020, data are very limited on whether infection confers immunity, let alone long term immunity.

While COVID-19 related coronavirus is still being studied, a similar SARS coronavirus from 2003 has been studied.

In a 2011 research study, scientists found that certain types of immunity called T cell memory did persist, while others (B cell related) did not. This immune memory response was more marked in severe infections as well. While this is promising that the human immune system can “remember” and potentially defend against repeat infection, the authors were careful to note that even T cell memory immunity did not necessarily mean the individuals were immune from reinfection.

Source: https://www.jimmunol.org/content/jimmunol/186/12/7264.full.pdf

Answer 4

I would take a bold personal statement (AFAIK as of now there are no accepted scientific knowledge of that matter) that they will be immune from specific mutation, but there are already more than one, see my question I just asked:

How virus is distinguished by PCR test (different mutations of sars-cov-2)?.

Link to news article:

https://www.cnbc.com/2020/03/04/coronavirus-chinese-scientists-identify-two-types-covid-19.html

So these reported re-infections could be infections by other mutation of the virus.

Answer 5

Blood samples for antibodies against the novel corona virus are tested in several Swiss laboratories.

The Inselspital Bern is currently not doing so because the quality of the results has not yet been adequately investigated, says the director of the University Clinic for Infectious Diseases. The problem is that detection of antibodies in the blood does not necessarily mean that someone is also immune.

Another problem in the use of blood tests as part of an exit strategy arises in terms of capacity: there is currently a shortage of test material in large quantities. This is confirmed by the Laboratory Medical Center Dr. Risch, where the first blood tests have recently been carried out in the laboratories in Buchs SG. The hospital staff, nursing staff and law enforcement officers have priority there, says Lorenz Risch, Chairman of the Board of Directors and Medical Director, towards SRF. Theoretically, you would have the capacity for around 1000 tests per day, but you can currently only make around a hundred in one or two days because the suppliers from Germany and the United States could no longer supply the so-called reagents.

https://www.srf.ch/news/schweiz/antikoerpertest-bei-corona-der-qualitaetsnachweis-ist-fuer-uns-noch-nicht-gegeben

The chief of the hospital says:

Antibody test at corona: the proof of quality is not yet given.

Answer 6

There is one report i am aware of, this has not been entirely confirmed. Information changes rapidly in a situation like this. The best we can do is take precautions, and wait for the experts to speak on a position of authority. Weather its possible that a virus in general can do this? Yes. It is also possible for it to hide in reservoirs that the immune system cant get at easily.

https://qz.com/1837798/why-some-covid-19-patients-might-have-tested-positive-twice/