Comments on: Adaptive immune defenses: Antibodies

By: Reinfection with 2009 influenza H1N1

Reinfection with 2009 influenza H1N1 — Mon, 28 Dec 2009 21:09:50 +0000

[...] a similar virus, a rapid antibody response occurs that is called the secondary antibody response. Antibodies are critical for preventing many viral infections, including influenza. But reinfection may occur if we encounter the same virus before the primary [...]

By: rau

rau — Tue, 01 Dec 2009 23:29:26 +0000

The minimum time for the H1N1 booster is 21 days, the recommended time by the CDC is 28 days but is there a maximum time when the booster would no longer trigger adaptive antibody response? I ask because my 1 year olds pediatrician is not scheduling boosters at this time due to vaccine shortages.

By: profvrr

profvrr — Mon, 09 Nov 2009 15:37:30 +0000

If you are already immune to H1N1 influenza, immunization with
inactivated vaccine will simply act as a 'booster'. The immunization
may be accompanied by typical reactions such as fever and soreness;
but these would happen even in the absence of prior immunity. If the
infectious vaccine is used (Flumist) the pre-existing antibodies would
likely render immunization ineffective.

By: concerned_parent

concerned_parent — Thu, 05 Nov 2009 01:47:00 +0000

I am just wondering what can happen if a person is already immune to H1N1 influenza an receives a H1N1 flu shot? Is it possible to have an adverse reaction to the vaccine for that reason?

By: profvrr

profvrr — Tue, 27 Oct 2009 19:33:48 +0000

How do you know you had H1N1 influenza? Was it diagnosed in a laboratory? If you did not have laboratory confirmed influenza, you should receive the H1N1 vaccine.

By: jan07121950

jan07121950 — Tue, 27 Oct 2009 14:38:39 +0000

if I have already had H1N1 this year can I have it again or do I need a vaccine

By: profvrr

profvrr — Wed, 05 Aug 2009 20:02:58 +0000

MBM and swhiting are both correct – the diagram is mislabeled. The constant region of the light chain should be labeled CL not CH. Thanks for picking that up.

By: swhiting

swhiting — Wed, 05 Aug 2009 07:42:19 +0000

A small point, but looking at your first antibody picture: should the “CH” in lower part of the left-hand light chain actually be labelled “CL”?

By: MBM

MBM — Sat, 25 Jul 2009 14:47:29 +0000

As ever, many thanks for all the effort you are putting in to educate us all.
I think there is possibly a typo on your first diagram: in the top left branch of the ‘Y’ there are two labels inside the blue (light-chain) loops, these labels read VL and CH, but I think the second of these labels should perhaps read CL rather than CH (since it is part of the light chain)?

By: Matt Dubuque

Matt Dubuque — Fri, 24 Jul 2009 03:01:58 +0000

Thanks, I get it now. I was reading the schematic incorrectly.

I do very much appreciate having the lessons in short chunks. I just found those two terms intruiging, as I tried to imagine what they might do.

By: profvrr

profvrr — Thu, 23 Jul 2009 23:38:23 +0000

There are two red lines, in the shape of a Y - those are the two heavy
chains. There are two shorter blue lines; those are the light chains.
Of course the antibody is three-dimensional, but the diagram is a
simple schematic of the four chains. Hope that helps. An explanation
of 'biological mediation' and 'complement binding regions' will
follow. I try to keep the posts short to encourage reading; longer
ones tend to be daunting. I'm trying to be understandable to as many
people as possible.

By: mdubuque

mdubuque — Thu, 23 Jul 2009 23:32:07 +0000

I'm having a little trouble interpreting the first chart of an antibody.

The text states that an antibody is composed of two heavy chains and two light chains.

However, on the diagram I can only find one of each. Is that because the graph is actually a cross-section of the 3-dimensional antibody?

Pretty basic question I know, but I wanted to be sure.

Also, I'm curious what the "biological mediation" and "complement binding regions" do. I imagine that discussion follows.

By: profvrr

profvrr — Thu, 23 Jul 2009 20:21:29 +0000

Adults had immunity to the 1977 H1N1 because a nearly identical virus
circulated in 1950 (http://bit.ly/LbPv4). Pre-1957, those adults who
had been infected with H1N1 in 1950 were only partially immune due to
antigenic drift. Adults have cross-reactive antibodies to 2009 SOI-V
because they are old enough to have encountered an antigenically
similar (not identical) H1N1 virus between 1918-1957.

By: profvrr

profvrr — Thu, 23 Jul 2009 20:11:33 +0000

Do you mean the drop in antibody levels after ~5 weeks? That would not
explain flu waves because memory should provide even more robust
antibody responses. The waves probably relate to exhaustion of
susceptibles.

By: gsgs

gsgs — Thu, 23 Jul 2009 07:03:05 +0000

why were adults immune against semi-pandemic H1N1 in 1977 (only children caught it)
but not against seasonal H1N1 in the years before 1957 ?
Why do some adults have antibodies against mexflu and children not ?
Does it come from the 1976 vaccine ? I can't believe it comes from
pre-1957 H1N1 which is similar to past-1977 H1N1

By: gsgs

gsgs — Thu, 23 Jul 2009 07:02:42 +0000

does this explain the duration of typical flu-waves, which go up ~5 weeks
and then go down ~5weeks ?