Perhaps I'm missing something, but I keep seeing info like this posted, so I'm going to say it again. The assumption of "antibody titers = immunity" is just FLAT OUT WRONG. "Antibody titers = immunity" is ONLY a valid maxim during the few months immediately after either infection, or vaccination. Example, If you had your MMR series as a kid, say 10 years ago, I 99.9% guarantee you that you do NOT have measurable or significant antibody titers against measles, but you ARE immune. The entire point of vaccines is to induce production of MEMORY B and T cells. These cells, when re-exposed to the pathogen, RAPIDLY divide and differentiate (B cells - the T cells "assist" the process) to produce antibodies and Helper T cells again for immediate pathogen destruction. This is a remarkably efficient and effective strategy used by nature. Having millions of antibody-producing cells cranking out antibodies simply NOT how the immune system works. Never has been.
A friend of mine got his second vaccine dose yesterday morning (firefighter in his 40s). Was quite feverish with a headache overnight and ended up making the considered choice to take some Benadryl which worked wonders. Wonder if there have been any studies on whether this appreciably mutes the end point of the immune response. I personally doubt it but who knows...don’t know whether anyone here knows from a theoretical (or historical) perspective whether that would be expected from an anti-histamine. Anyway seems like having some Benadryl on hand might be helpful when it comes time for the second dose.
Seems like the CDC is being cautious here (basing their recommendation on known longevity of the high antibody levels - they may extend this window as time goes on). Is it possible that someone who had low antibody titers (say a year from now) might be briefly more contagious if they have an incipient infection, yet antibodies have not been rallied by the memory B cells and helper T cells, yet? Whereas someone with high antibody levels would immediately neutralize virus and prevent replication, with basically zero chance of transmission. Some idea of the time scale of the ramp up of antibody production would be interesting to know.
I agree with the guidelines, except this point: "Are within 3 months following receipt of the last dose in the series" That is a "we don't have data beyond a few months, so we cannot make a prediction" if you ask me. Like all things with the CDC and this pandemic, it is a moving target that I expect will be revised once we have more data.
I could be wrong now after reading your post. But, I thought the medical labs test IgG tigers of MMR and varicella. I swear I remember getting a varicella test as an adult (not that I was infected with it but was curious because I don’t recall whether I was ever sick from it as a child) and, if I’m not wrong, the blood draw tested IgG levels.
The CDC's bullet point that I listed doesn't jive with everything we know about viral immunity. Hence my assumption that whomever wrote it is erring on the side of caution.
Most likely that's a higher-end lab-based test, likely an ELISA or even flow-cytometry (yep, I just showed my age with that one). Level of detection should be much better on a test like that. For COVID-19, these rapid tests circulating around for point-of-care testing won't pick up levels that low, usually, although that kind of QA analysis on the tests is on-going as the pandemic continues. They were not designed for that level of sensitivity. Then on top of it, we have multiple variants of the virus to consider (i.e. different antibodies), and it is expected that the more the virus mutates, the less sensitive these antibody tests would be (since they were "built" against the original strain). Again, more QA that the test makers should be actively performing, but will be a considerable time before we have that data.
Anecdotal evidence here about my personal reaction to second dose of Moderna. No reaction, not even sore injection site, to the first dose on January 12. Second shot came on February 9 at 1:30 p.m. All fine when I went to sleep at 10 p.m. Bathroom wake up call at 3:30 a.m. and arm was very sore at the site and sore muscles around it. Also had a hint of a headache. Got up at 6 a.m. with a solid headache and a temperature at 99.1 (my normal is 97.6). At 7 a.m. chills began and headache was very uncomfortable, but I did not take pain reliever. Back in bed to get warm. By 2:30 p.m. temp had hit 100.6 and headache bad enough to go for the ibuprofen bottle! I took 400 mg and returned to bed with chills subsiding. At 5:00 pm I returned to normal on all counts! My wife had only a bit of soreness in her arm and a few muscle aches. My conclusion is that if you can laugh hard enough and long enough at your miserable husband, the second shot is no big deal.
So... Now that the COVID wave swept through my house and things are back to normal I am still pondering some things... How could I not catch it when I was living with 2 infected people? My wife is of the opinion that I did catch it, but was asymptomatic, and the antibody tests were wrong. (False negatives do happen.) I have this other thought... Way back at the start of COVID (Feb 2020), I did feel a bit sick some weeks before my office was shut down, and 6 months later had an antibody test that was also negative then. In Jan/Feb 2020 I was working in an area where the first case in California (and first death) from COVID had been reported, so it is possible that I had caught it really early (before people were even alerted to be watching for symptoms.) Maybe I have had B cells trained on this for nearly a year so I was able to quickly squash it this time without symptoms and getting another negative antibody test? Do they have any sort of test to check if you have B cells trained on this? So... Maybe my first antibody test was too late after infection to read any more short term antibodies, and my more recent antibody test was negative on re-infection because I had B cells leftover from before so my body cleared it out so quickly that I was already antibody free by the time I took the more recent antibody test? The (lack of) accuracy on these tests, and the importance of the timing when they are taken makes it hard to fill in all the dots on what may have happened. So... I had a negative antibody test ~6 months ago, a recent negative PCR 5 days after being exposed, and a very recent negative antibody test... How likely is it that I have never actually had it? I am not sure, maybe I just got tested at the wrong times to catch COVID "red handed" and I did already have it before? Also... None of my tests were "rapid test". All took days to get results. The most recent antibody tests were both IgG and IgM. (I am not sure exactly what that means, but they did both.) I guess eventually I can see how I react when I get first shot of vaccine.
^^^ By the way, back when I had felt sick (fever/chills/runny nose/mild cough) in Feb 2020, I had heard of COVID on the news but it was said to be only in China at that point, so I assumed I just had a bad cold. When timelines were rewritten months later to say it was in the SF bay area earlier than first thought is when I decided to get my first antibody test to see if I already had it. But enough time had elapsed that it was likely an inaccurate time to do that sort of test. (This person had lived very close to where I was working at the time: How the Nation's First COVID-19 Death Went Undetected in San Jose | KQED ) When my office finally shut down in March it was because known cases had started to show up in the area. What we know about the Bay Area's first COVID-19 deaths
Assuming you were living with your wife at that point in time, why didn't she catch it then? Just asking, another 'what-if' in a long list of them..
I guess many of us think we got it in Q1 last year. I had a month long cold/cough in March - so did my wife, though kids got over it soon. I even got a home test - but after a month. But still, most likely we didn’t get Covid at that time. Common cold was still much more common at that time
Yeah, it's hard to tell who's going to get it, and who's going to get lucky. My Mom and stepfather live in an assisted-living facility, which for months was in lockdown - no visitors in the building, no leaving the building except for doctor visits, and no wandering the building except for one reserved walking slot a day and one small distanced event a week. Despite that, my 85-year-old stepfather got COVID (they believe from the next-door neighbor who had a family member sneak in through the garage; my stepfather would sometimes talk to the neighbor in the hall despite the prohibition and my Mom nagging at him not to do so). My 77-year-old mother lived with him in a 2-bedroom apartment. Once he tested positive, he mostly stayed in his bedroom (although he has Alzheimer's and forgot a lot); the staff told my Mom she was almost definitely going to get it, but she wore KN95 pretty much except when sleeping in the other bedroom, and wiped down all surfaces constantly. They estimate he caught it about 3-4 days before their testing showed he had it; so they'd spent a fair amount of time eating at the same table, and sitting in the same living room (though their chairs are at opposite windows). My stepfather survived easily (his symptoms were fairly mild, except for one day), and my mom managed to avoid getting it (good thing as she's overdue for heart and lung surgery and I'm less certain she would have done well if she had caught it). She has type-O blood and takes vitamin D supplements; maybe one of those helped, maybe not.
When I started taking extra vitamins and supplements through all this, I figured they might help lessen symptoms slightly if I caught it, but not help avoid catching it. Also, back at the beginning I figured Zinc was going to be the most important thing, but is sounds like vitamin D is the best thing going. Not sure what to credit if I really didn't catch it ever. ( I do NOT have type O blood in case that matters... )
For ex-military, check with the VA for vaccination. One of my staff who is 50 years old received his first shot this week.
Can you test positive after being vaccinated for COVID? Yes, experts say, and it's an expected but rare event "Four people in Oregon tested positive for COVID-19 even though they’d been fully vaccinated and enough time had passed for their second doses to become fully effective, state public health officials announced Friday. The news makes Oregon one of the first states in the nation to identify so-called “breakthrough cases” where people who were considered immune have now been sickened with mild cases of the disease. ... “I anticipate that more states will be reporting more numbers of breakthrough cases as they have more people who are fully vaccinated,” ... He said they either had no symptoms or mild symptoms."