Wikipedia:Reference desk/Archives/Science/2019 October 16

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October 16

Flu Jab

When getting the flu jab, there is a form that needs to be filled out. One of the questions asks, how do you feel at the moment. Hypothetically if one were to fill this in and say you were healthy but actually you already had the flu, what would the outcome be? Would you end up with pneumonia Also, what is the difference between pneumonia and simply having the winter flu? How would one tell the difference between really bad flu and pneumonia? This just a hypothetical, its not a request for medical advice. I am more curious in the science behind it. Thanks Anton 81.131.40.58 (talk) 10:53, 16 October 2019 (UTC)

See https://immunisationhandbook.health.gov.au/vaccine-preventable-diseases/influenza-flu for some government information. I will leave you to read this and figure out whether immunization is recommended when you are already sick. Graeme Bartlett (talk) 11:06, 16 October 2019 (UTC)

To the final question, pneumonia, which you linked, is an inflammatory condition of the lungs, which is caused by various infections as well as non-infectious conditions (though infection is vastly more common). Pneumonia is not itself an infection. The flu is generally experienced as an upper respiratory tract infection, well clear of the lungs themselves. Someguy1221 (talk) 11:13, 16 October 2019 (UTC)

Yes, but the influenza article says that bad cases can lead to pneumonia, so my question is, how would one known when the trasition has happened? Thanks Anton 81.131.40.58 (talk) 11:37, 16 October 2019 (UTC)

The Wikipedia article titled Pneumonia has an entire section labeled diagnosis, that should tell you how one would know when one has pneumonia. --Jayron32 12:17, 16 October 2019 (UTC)

Exactly. But just to emphasize Someguy's point, pneumonia is not what you "catch", it's what you sometimes experience depending on how what you've "caught" has progressed. You could substitute conditions like "persistent cough" or "post nasal drip" - you don't "catch" those; you "caught" the cold or flu or whatever and it has infected you successfully enough to induce those responses. It may seem like a technicality, but it's an extremely important one. Matt Deres (talk) 20:26, 16 October 2019 (UTC)

Note also per the article, bacteria are more common causative agents than viral ones in most situations, although causative agents cannot always be identified. So if you just know someone has pneumonia it's not generally wise to jump to influenza without further information. Nil Einne (talk) 07:53, 17 October 2019 (UTC)

Also, also important is the notion of secondary infection, which means that, strictly speaking, the pneumonia may not be caused directly by the influenza virus, however the flu may make one susceptible to other infections, and those OTHER infections may be what causes the pneumonia. --Jayron32 12:14, 17 October 2019 (UTC)

@ Someguy - According to the Mayo Clinic the signs and symptoms of flu are:- fever over 100.4 F (38 C), acheing muscles, chills and sweats, headache, dry, persistent cough, fatigue and weakness, nasal congestion and sore throat. That list seems a bit more than an upper respiratory tract infection and that is probably because influenza is a body-wide infection. (Anecdote warning) Having had flu 3 times in my life it is well beyond a URTI in my experience. Richard Avery (talk) 22:28, 17 October 2019 (UTC)

Hi Richard. That is a very crucial observation, but it might not mean what you think it does. Or "upper respiratory infection" might not mean what you think it does. Or maybe your statement doesn't mean what I think it does. Anyway, the cells that are infected by a virus do not necessarily coincide with the organs that develop symptoms. Because the immune response to an infection includes the release of systemic signalling molecules, the entire body can feel the effects. I'm not sure of a single article that goes over this in good detail, but I'd direct you to cytokine, chemokine, interferon, and the woefully short immune response. Someguy1221 (talk) 08:14, 18 October 2019 (UTC)

I got a flu jab a couple days ago and didn't have to fill anything out. They asked if I had any allergies to them and I said no and I had a jab 2 years ago with no noticible side effects. I didn't fill anything out that time either, iirc, and it was at a different facility. 173.228.123.207 (talk) 23:27, 17 October 2019 (UTC)

I take it "jab" is a Britishism? ←Baseball Bugs ^{What's up, Doc?} carrots→ 00:54, 18 October 2019 (UTC)

Indeed, equivalent to 'jag', which is a Scottishism. Richard Avery (talk) 07:24, 18 October 2019 (UTC)

Jab would be an injection and as far as filling out form, I assume that different countries do it differently. Anton 81.131.40.58 (talk) 15:27, 18 October 2019 (UTC)

You seem to be worrying that having the jab will make things worse. You do realise that the flu innoculation is dead and you cannot get flu from having it?[[1]] --Ykraps (talk) 18:29, 21 October 2019 (UTC)

Not a single person, not even the OP, said that. You were the first person to bring it up. It's a good thing to mention, but literally no one here mentioned anything about it before you. --Jayron32 18:32, 21 October 2019 (UTC)

The OP asked what the outcome would be if he put down that he was healthy when he wasn't. That seems an odd thing to ask if you're not worried that the inoculation will make your health issue worse.--Ykraps (talk) 19:47, 21 October 2019 (UTC)

In the States at least, it is definitely not recommended to get a flu vaccination if you're already sick. I don't really know exactly why, but it's what they always tell you. Presumably it's for some reason other than a worry that the vaccination might give you the flu. --Trovatore (talk) 20:27, 21 October 2019 (UTC)

Although you're not injected with a live virus, your immune system will attack it, and if you're already ill, you could further compromise your system. Plus (and maybe more likely), this could be kind of a disclaimer in case someone lies about being sick and then tries to sue the makers of the vaccine. ←Baseball Bugs ^{What's up, Doc?} carrots→ 22:28, 21 October 2019 (UTC)

I suppose contention for immune resources is one possibility, though I have never really heard of that. Another I can think of is that the vaccination might provoke an immune overreaction, such as a cytokine storm. But both of these are speculation; someone should be able to find out the true rationale. --Trovatore (talk) 02:25, 22 October 2019 (UTC)

I was on the right track. Here's a detailed explanation.https:// www. verywellhealth .com/ what-will-happen-if-i-get-a-flu-shot-while-im-sick-770545 ←Baseball Bugs ^{What's up, Doc?} carrots→ 03:59, 22 October 2019 (UTC)

The NHS says it's a good idea to delay the jab if you have a fever (although it doesn't say you have to) but for minor illnesses with no fever, there's no problem.[[2]] The website User:Baseball Bugs has provided recommends the same but talks about a significant fever with a temperature of over 101f. The possible outcomes are also given so the OP can extract his answer from that.--Ykraps (talk) 07:54, 22 October 2019 (UTC)

I have to say I also wondered if the OP was confused on the issue and thought of replying when I first saw this so Ykraps is not the only one.

As a point of clarification Live attenuated influenza vaccine does exist but it's a nasal spray not a jab. The risk if getting an infection from that is very low. Still as per the source from the manufacturer, such vaccines as I think with all live attenuated vaccines, are not recommended for immunocompromised patients. In fact, that vaccine isn't even recommended for those who care for severely immunocompromised patients (i.e. "boy in the bubble" type), or if they receive it they need to avoid contact for 7 days. See also the CDC [3]

As for the original question, when I first read it I had a look but could only find crappy sources like the one BB provided so didn't link to them. Looking again I found [4] which is very slightly better but it's still a blog. Although these are not great sources, they do tally with what I would expect. The primary concerns is there could be confusion over whether you are having a reaction to the vaccine as well as the possibility your immune response won't be as strong leading to lower level of immunity.

I would note that that blog is from the US and specifically says there's nothing wrong if you simply have a mild sickness, it's particularly if you have a fever it isn't recommended. (To be fair, a flu is not likely a mild sickness unless in the early stages.) I'd also note it's written by a MD at the student health services of a university, and the way it's written it seems likely that this is based on how they handle things there so it's not simply abstract. It also mentions some health care providers are starting to think it may be better to do it anyway with fevers because people may not get the vaccine if asked to delay.

The CDC also mentions that only moderate to severe illness with or without a fever are a barrier [5].

Nil Einne (talk) 15:48, 22 October 2019 (UTC)

Seto Inland Sea land reclamation

Were there any plans in the past to drain part or all of the Seto inland sea, reclaiming the area for farming and housing? Thanks. --2.37.200.57 (talk) 14:33, 16 October 2019 (UTC)

The notion of draining Setouchi may have arisen but been left to languish like that of Atlantropa because investors in such a project would be deterred by a geologist's risk assessment of the area prone to subducting sea plates, recurring tsunami-producing earthquakes and volcanos on the Pacific Ring of Fire. DroneB (talk) 15:03, 16 October 2019 (UTC)

Yes, some for industry and rice production, see Figure 35 here [6] (it's unlabeled). Some of the reclamation was under the 1962 plan of the Comprehensive National Land Development Act of 1950.—eric 18:41, 16 October 2019 (UTC)