Is one vaccine dose enough if you’ve had Covid? What the science says | Hacker News Reader

Is one vaccine dose enough if you’ve had Covid? What the science says

nature.com

32 pointsdsr1242 comments

> Research shows that a previous coronavirus infection plus one dose of vaccine provides powerful protection — but concerns linger

This is one thing that’s been incredibly frustrating throughout this whole pandemic. Studies and research will show B, with no sign of A, however inertia/politics/fear/ignorance will continue to push A to the point of harm.

An example - a local store was insisting on wiping down the entire checkout conveyor with alcohol between every single customer until very recently, when we’ve know for a long time that you won’t get COVID from that.

Security theatre.

It’s about feeling safe, not about being safe.

> a local store was insisting on wiping down the entire checkout conveyor with alcohol between every single customer until very recently, when we’ve know for a long time that you won’t get COVID from that.

As someone from a country where running orders are still to disinfect often-touched surfaces (switches, door handles, office desks, etc.) I was surprised by this.

I went to check what CDC from US recommends. It turns out it's pretty much the same:

> Clean high touch surfaces daily. This includes tables, doorknobs, light switches, countertops, handles, desks, phones, keyboards, toilets, faucets, and sinks.

(from https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-si...)

So maybe wiping down the belt between every customer is a bit excessive, but it seems my sources don't agree with the "you don't get COVID from that" part.

https://www.nature.com/articles/d41586-021-00251-4

Cleaning for an airborne illness is just theater. Upgrading air handlers, increasing airflow, and spacing people further apart matter. Cleaning stuff randomly just makes people feel better (but can make good business sense because of this!)

yes, cleaning surfaces regularly (but not excessively) is good for a variety of reasons, but not for covid. the airflow concern is also overblown though. you really just need modest distancing indoors (or masks, absent modest distancing). no need for fancy airflow handling. covid isn't a robust virus that, as it's tiny water-bubble craft rapidly evaporates, quickly falls apart outside the body (similar to why surfaces aren't a concern).

Yes it can make good business sense, but for those who know it's just theatre it certainly won't work.

But it's really hard to stop it when the mantra is "Better safe than sorry".

As vaccines grow in numbers and we have solid information like the one linked here, i have faith that we can return to doing things we know work.

> Clean high touch surfaces daily.

A checkout belt isn't even close to a 'high-touch' surface - I don't think I've ever touched one, and neither do the checkers. And the difference between 'daily' and 4-500x daily is dramatic.

> France, Germany and Italy, among other countries, now advise only one dose of vaccine for people with a healthy immune system and a confirmed previous diagnosis. Many scientists who have studied immune responses to vaccination say such policies are a sensible way to make the most of limited supplies in countries that are racing to inoculate their populations.

At least for France, their Infectious Disease professionals go further. They're of the opinion that a second dose in someone that's been infected (within a certain range of time) is subjecting them to unnecessary treatment, wasted time and side effects for no/limited benefit.

It's not to make the most of limited supplies.

Auto-translation (with some readability tweaks):

> If the second dose of vaccine has already been administered to people with a history of infection with SARS-Cov-2, the data available to date do not show any difference in the safety profile apart from the occurrence of more common systemic reactions.

https://www.has-sante.fr/jcms/p_3237271/en/strategie-de-vacc...

But questioning the value of a vaccine under any circumstances is ban-worthy in a lot of places.

Why doesn't getting Covid and then allowing your body to produce your own immunity not protect you from getting it again?

As I understand the variants are not like the flu or the cold (yet!)

iirc for some reason the amount of antibodies you have falls sharply after 1-3 months and you're vulnerable again. anecdotally, a friend of a friend (EMT) had covid like 4 times before vaccines were available.

Can someone explain why this would not be the case for vaccines?

If antibodies fall off quickly from an actual infection, why would this not also happen for the antibodies produced because of taking the vaccine?

Antibody count falls at first, but relevant antibody-producing cells were found[0] to remain in the bone marrow. I suppose it is not the only determining factor in susceptibility to symptomatic infection, though.

I’d be curious if currently available vaccines stimulate such preexisting antibody-producing bone marrow cells of past COVID patients (which sounds more optimal on the face of it), or they trigger yet another variety of antibodies to be produced in addition to the “native” one.

[0] https://www.nature.com/articles/d41586-021-01442-9#ref-CR1 “Had COVID? You’ll probably make antibodies for a lifetime”

It probably does.

We just haven't had enough time to prove it yet, or to investigate the differences between variants.

According to this (preprint) paper(n=52000), recovering from covid-19 protects just as well (or even slightly better) than getting vaccinated.

Also note that vaccines focus on the Spike protein only, and you're immunesystem takes the entire virus into account, which might offer better protection against variants.

https://www.medrxiv.org/content/10.1101/2021.06.01.21258176v...

PHE are doing one too:-

https://www.gov.uk/government/news/past-covid-19-infection-p...

>>PHE scientists working on the study have concluded naturally acquired immunity as a result of past infections provide 83% protection against reinfection, compared to people who have not had the disease before. This appears to last at least for 5 months from first becoming sick.

seems like there's some consensus on two "exposures" worth of immunity being valuable.

any data on second shots for folks who took the J&J?

I don't think they've published any data relating to ENSEMBLE 2 yet.

The cynical part of me thinks that J&J is only 1 shot because your body develops strong immunity to it adenovirus-26 vector, so a 2nd shot would get immediately killed off before its spike protein payload could take any action. Until your immunity to it wanes anyway.

This is suspected to be a problem with the Oxford vaccine which also uses one virus vector for both doses.

Like Sputnik V, J&J's Janssen unit's Ebola vaccine uses two different virus vectors. And Janssen is doing an ENSEMBLE 2 Phase III clinical trial with two doses eight weeks apart that lol768 mentions. But their primary objective stated from the very beginning was to create the most effective single dose vaccine possible, and vaccinated a billion people in 2021.

They appear to have achieved the former, although Sputnik Lite with the same Ad26 based vector could be a competitor, the latter goal is failing due to inherent issues with using cell culturing to make something, a strained supply chain for that which is also required to make Oxford's Sputnik V, and Novavax's vaccine (bug cell grown protein plus adjuvant), and being forced to use the dangerously incompetent Emergent BioSolutions as a subcontractor.

Was J&J the most effective vaccine after 1 dose? Sure they don't have much competition if you only compare against 'approved' schedules, but mRNA vaccines seem better after 1 dose than J&J is. But yeah, there's just not a lot of trial data out there for 1dose mRNA or Oxford vaccine since they're (officially) pretty quick to get you to 2 doses.

Emergent BioSolutions was contamination between the J&J side of production with the Oxford/AstraZeneca vaccine side of production...

Natural immunity is way better than any vaccine. You don’t need a vaccine if you already have antibodies.

The study used 26 participants? Did I read that right?

What is the preferred sample size to back these sorts of claims?

Not sure why they'd focus on a study out this week, there have been several others, e.g. the first 5 references in this Letter published a month ago: https://www.thelancet.com/journals/ebiom/article/PIIS2352-39...

Thank you. Five studies referenced in there, with "limited participants" but complimentary results. Very cool.

I often hear from people that recovered from Covid that they don't need the vaccine, Rand Paul is one notable example, due to their natural antibodies.

I'm curious to know what the average antibody titer level of previously infected people is to start. Or how much more protection do they get once vaccinated?

If infection rates were double digit, the "think of what we could save" argument might perhaps deserve some consideration. But as it stands, I feel the only warranted concern is the well-being of Covid survivors.

I wish there was an easier way to figure out if you had COVID.

As someone who's only got one dose so far, I would gladly skip the second one if I knew for certain I had COVID before, so someone else could get my second dose.

Did you not get an antibody test at some point prior to the vaccine? That would have given you an answer with 99% certainty if you used a good one.

I think they are relatively expensive, ~$200. Probably worth it though.

We would need some form of official recognition of antibody tests though. Pretty sure most places that require vaccination don't accept antibody test results.

Antibody tests at the supermarket clinic here is $40. Unsure if that’s a crappy test or if any subsidy is provided. $40 vs $200 does seem like the usual EU vs US markup too I guess

Ah, not bad

I believe the Red Cross tests for the antibody when you give blood, as well.

Antibody tests have been widely made available for free across the developed world.

In NYC, for example, they've been available for free at a ton of different sites. It may always be as convenient or quick, but it's free.

Antibody tests were only widely available in July-August, so people who got COVID in Feb or March often didn't have high enough antibody counts by that point to flag positive on the tests.

That's not true.

The half-life of antibody levels has been estimated at 73 days. The antibody tests are quite sensitive, time has not been enough of a factor yet to produce false negatives. In a year or two it might be.

The only time concern is that you need to wait 2-3 weeks until after you recover from COVID to ensure you test positive.

Don't some antibody tests do this? I think antibody tests that detect antibodies to the nucleocapsid should be unaffected by the vaccines, which only spur resistance to the spike protein.

See the section called "Binding Antibody Tests" here:

https://creakyjoints.org/living-with-arthritis/coronavirus/c...

This is true of some - but not all - of the vaccines. The whole inactivated virus vaccines contain more than the spike, but the mRNA and vector vaccines only contain the spike.

[never mind]

The article is not advocating doing anything unsafe or otherwise endangering others. The scientific question is quite valid - do we have to use our limited vaccine supply to ensure all get two doses or can we save a dose on those who already had COVID and give it to someone who needs it?

First paragraph of the article: “Many people who’ve been infected with the coronavirus might be able to safely skip the second jab of any two-dose vaccine regimen, a growing number of studies suggest. These results could help to stretch scarce vaccine supplies and are already influencing vaccination policies in some countries.”

US might have enough for everyone, and wouldn’t it be also great if we didn’t need as many doses and could share with hard hit places like India? I see this as a net positive if true.

The US is in desperate need of people who are willing to take all the vaccines the government has purchased for us. What’s the shelf life on the mRNA products? Looks like Moderna’s lasts for six months in the freezer. Pfizer for 30 days on dry ice, another 30 days in a regular freezer?

Lots of doses are going to get tossed. Most the people who are going to get the shot have gotten it already.

A test for antibodies against N protein will tell you if you had COVID or not.

T-cell tests are available in some places now.

https://www.tspotcovid.com/

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