as of this year, we <can><have been able to> detect antibodies

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Senior Member
Hello to all,

Thanks for reading my post.


Do You Get Immunity After Recovering From A Case Of Coronavirus?

Sample sentence:

"We've gone back and gotten samples from patients who had SARS in 2003 and 2004, and as of this year, we <can><have been able to> detect antibodies," says Stanley Perlman of the University of Iowa. "We think antibodies may be longer lasting than we first thought, but not in everybody."


"Can" is used in the original. Would the sentence also be correct with "have been able to"? I'm wondering whether the present perfect can be used here because they acquired that ability in the past (some time ago within the current year) and have had it since (up to the present moment).

Thanks a lot for any comments, corrections or suggestions!

  • Edinburgher

    Senior Member
    German/English bilingual
    How do you mean "they acquired that ability in the past"? Who acquired what ability?
    The statement is not about acquiring an ability to detect antibodies. The main message here is that those patients still have antibodies from 16/17 years ago, because we can still detect them now.

    If you want to paraphrase "can" using "able", it should be "are able to".

    It's not about technological ability, it's about tests for the antibodies actually being positive.


    Senior Member
    English - U.S.
    They have probably been taking those samples every year. What he is saying is that, even this many years later, they can still detect antibodies in the most recent blood samples. The antibodies have not disappeared over time. It would be new news if they detected that those antibodies no longer exist in those people's blood.

    and as of this year,
    This is him saying that the most recent tests took place just this year (perhaps spurred by this crisis, perhaps regularly scheduled) and the results haven't changed. As of this year, those results are the same. What he can't promise is that those results will be the same next year or the year after. He can only tell you what's true as of this year.

    As Edinburgher says, a suitable replacement in this sentence for this context would be "are (still) able to".
    Last edited:


    Senior Member
    English - U.S.
    Long-Term Persistence of IgG Antibodies in SARS-CoV Infected Healthcare Workers

    This is a link to a study by a group that is doing something similar.

    Here's an excerpt:
    A long-term prospective cohort study followed 34 SARS-CoV-infected healthcare workers from a hospital with clustered infected cases during the 2002-2003 SARS outbreak in Guangzhou, China, with a 13-year follow-up. Serum (i.e. blood) samples were collected annually from 2003-2015. All sera were tested for IgG antibodies.... RESULTS: Anti SARS-CoV IgG was found to persist for up to 12 years. IgG titers typically peaked in 2004, declining rapidly from 2004-2006, and then continued to decline at a slower rate. IgG titers in SARS-CoV-infected healthcare workers remained at a significantly high level until 2015
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