A big question is how long it’ll last: if you got a yearly shot like the flu, that might be enough to prevent widespread outbreaks even if it doesn’t go away and people who are immune compromised still have to worry.

The other would be whether it helps with partial immunity: it doesn’t need to be lifelong immunity to be worth using if, say, it shifted the serious case rate down by a fair margin.

Given that Coronavirus mutation rates are orders of magnitude lower than influenza viruses, a yearly shot is unlikely.

How did you come to this conclusion? I’ve been curious about it for some time but haven’t seen anything concrete which could explain this at a level I understand.

I wasn’t referring to that but simply the concern that immunity might be relatively short lived: given how well this spreads even a vaccine which only gave, say, 10-12 months might be worthwhile if it meant that we could have schools, transit, restaurants, bars, churches, etc. able to operate normally.

Mutation is not the only factor determining how often a vaccine would be given. If antibodies only last a year from the vaccine dose, it should still be given yearly, even if the virus has not mutated.

It won’t be optimal, but if you stockpile enough and then administer it all at once, it effectively grants herd immunity for about two months, and the virus isn’t able to transmit during that time. Two months is longer than the incubation period of the virus. So you see where this is going.

Now if it isn’t close to 100% effective then you’ll probably still need people to quarantine, so, good luck with that.

I thought immunity wasn't a perfect correlation with presence of antibodies.

If enough people take the vaccine with that expected length of protection, it would certainly tamp down the spread at minimum. So it might still 'work' by collective standards.

The simple act of producing the vaccine and then administering it would take much longer than a few months.

I believe we are fast-tracking production of several vaccines on the assumption that they might work. So even though testing is still going on, currently producing them just in case.

They begin the manufacturing process of the vaccine well before it even finishes phase 3 testing.

The most significant safety issues with this vaccine specifically regard the 250ug dose, which was not used in Phase 2 and won't be used in Phase 3.

As long as it's not a Grade 3 fever, I don't see a problem: many vaccines can cause (transient) fevers. (Part of that is due to the adjuvants used to prime the immune system by causing a localized inflammation).

I got a shot for the yellow fever a few years ago and I felt quite bad for a couple of days. When I was asked for a booster shot for measles, I was warned of the possibility of developing fever for a couple of days as well.

Similarly, children very often get fevers after some of their first vaccines. It's no big deal.

Vaccines aren't completely harmless, but this would be expected. You can do a self test with a flu vaccine. Your doctor probably will recommend no exhausting activities for a few days after taking the shot. If you, for science, ignore that advice, you might feel quite horrible.

Every time I get the flu shot it feels like someone punched me hard on the shoulder where it was administered for a couple days, and I feel generally unwell (but not 'bad' per-se).

But the alternative is I could end up in the ICU with pneumonia without it (and have, in the past, from the flu), so the risk/annoyance is worth it.

My experience with DTP shots is that one of my arms is a useless-but-painful dead weight for a week or so. I'd still take that over getting tetanus.

Perhaps I should rephrase it, didn't want to make it sound like getting vaccinated is a bad idea. It does activate your immune system though and that can make you feel really unwell. Fever is not a disease, it is an immune response. But those can still induce complications. Doctors won't administer a shot if you already have pneumonia for these reasons.

I felt absolutely nothing.

I used to administer flu shots as an Army medic back in the day. I don't recall ever receiving or giving this warning.

Kids especially frequently get fever after vaccines. It's very common.

I'm a generally healthy 30-something and I always get a reaction from a flu shot - fever, swollen lymph node, pain

The worst I've gotten from a flu shot is mild muscle discomfort at the injection site for the first 24h.

Does that actually happen to people? I thought it wasn't too common. My family gets this warning every year when we get our shots, but we never experience any of those effects. My kids complain about the arm pain, but even I don't get that part of it. Nothing changes for me after getting the flu vaccine (other than the protection of course).

Just to be clear I do HIIT, strength training, and (my favorite) lots of yard work regularly and the flu vaccine doesn't interfere with any of that.

I've never heard the exhausting activities warning, but I do get mild flu-like symptoms for a few days (low grade fever, some fatigue, congestion) after the flu shot most years.

I don't know how common it is to experience this, as I would say I have a subpar immune system (frequently sick as a kid, history of food allergies, etc.). But when I've discussed it with doctors they do say my reaction is unsurprising, however the benefits outweigh the "costs".

Oh, yes, I have seen that very often. Symptoms are nearly the same as getting the flu. The type of vaccine, live or inactivated, is relevant though, but it can happen with both. Your immune system is weakened for a time until you have produced. Moderate training is no problem though, perhaps even helpful, but exhausting yourself can lead to problems.

I feel like the psychological element goes the other way, at least for me.

In January, this would have felt like a terrible deal. Right now, it feels like you're telling me that - should I socially isolate for a few weeks a year after vaccine shots - I can largely go back to living a normal life. That feels great.

Why would isolation be required after taking the vaccine? You should be able to resume normal life as soon as you’re well enough, right?

Fair. I think that the "sick with Covid == stay at home" link is strong enough in my brain I'm just assuming you'd want to stay home with even the vaccine, but that's not something really based in scientific fact.

Couldn't you have gotten the disease shortly before vaccination and potentially be contagious for some period afterwards?

That will partly depend on how it's rolled out. If we coordinate and get lots of people the vaccine in a short amount of time, then it will help a lot because we'll get the effect of herd immunity. If it only gets to a few people at a time, it will help less.

It also depends on the efficiency of the second round. If it works great the first time you get the shots, but when it wears off and you get a second round it doesn't work as well that is bad.

From the original article, it sounds like the first round is only minimally effective, and the major boost comes from the second round.

This is a confusing area. The two shots are part of round one. When that wears off and you get more (which might be 2 more shots) that is the next round.

If english has a good way to say this I'm not aware of it.