Skip to content

Travel restrictions are crazy now that we have COVID-19 vaccines

Canada is apparently a COVID nightmare these days:

The Centers for Disease Control and Prevention on Monday advised Americans to avoid travel to Canada, citing “very high” levels of the coronavirus. Canada was placed under a Level 4 travel health notice — the highest category.

....“Because of the current situation in Canada, even fully vaccinated travelers may be at risk for getting and spreading Covid-19 variants,” the C.D.C. said.

This makes no sense. It's true that COVID cases have soared in Canada, but by every possible measure they're still in better shape than us. They have a lower case rate, a lower hospitalization rate, a lower death rate, and a lower number of unvaccinated yahoos. Visiting Canada is safer—substantially safer—than staying in the United States. Here's what it looks like in numbers, with Canada scaled to 100% in each category:

So why advise people not to visit? It's nuts.

For that matter, travel restrictions in general are nuts. If you accept only fully vaccinated visitors—and every country does—then the visitors you're getting are safer than your own populace. They're 100% vaccinated! You should welcome them and their money.

So why don't we? Why doesn't everyone?

82 thoughts on “Travel restrictions are crazy now that we have COVID-19 vaccines

      1. MontyTheClipArtMongoose

        Which your side would fully support, correct?

        Of course, your pre-screened offer to attend CPAC Budapest 2022 says otherwise. (Specifically, it says you must be unvaxxxed against the intentionally lableaked Chinese military bioweapon plandemic flu-like nothingburger to get priority admission to the Viktor Orban Events Center.)

  1. rick_jones

    But Kevin, shirley the advisories from the CDC as based solely on the best available science?

    The NYT blurb you cite does not saw, but is there any chance the rate of change in Canada might take them to worse than the US in the not too distant future? Elsewhere you refer to nowcasts out of models. Something similar here?

      1. kaleberg

        I didn't even notice that, but since you called it out, I reread your original comment and noticed "shirley the advisories". It's impressive how the human brain automatically undoes auto-correct.

  2. jte21

    On a related note, here's a fun data-oriented question that Kevin might want to tackle at some point: has the vaccine mandate for businesses, especially bars and restaurants, harmed business? The New York State Restaurant association says yes! The evidence? a poll they did of 125 restaurants in NYC showed some 3/4 had lost businesses due to the mandates, with over half claiming those losses were "significant". (article here: https://www.restaurantbusinessonline.com/operations/nycs-vaccine-mandate-has-been-disaster-restaurants-study-finds)

    They don't say if this was an actual random poll, or some kind of self-reported one, in which case the results don't tell us much. Second, it's estimated that there are roughly 25,000 eateries of various kinds in NYC. Finally, NYC is well over 80% vaccinated (adults, at least), with the lowest rates found in the heavily orthodox Jewish sections of Brooklyn and parts of Staten Island, a well-known conservative redoubt in the otherwise dark blue city. And those are still something like 75%. Some neighborhoods of Manhattan are close to 100% vaccinated. So how likely is it in a city with that level of vaccination that the vast majority of restaurants are seeing business crater because unvaccinated people are refusing to patronize them? I'm highly suspicious. I wish restaurants in my part of the state had a vaccine requirement. I would eat out a lot more, especially nowdays.

        1. Crissa

          That seems to be wrong.

          Our fan-convention was just canceled because we lost a quarter of our staff and artists who canceled and stayed home.

    1. KinersKorner

      In NYC If there were no mandate no one would eat out. They are idiots. They should ask their customers. Manhattan just about everyone is vaxxed. You need to work and go out.

  3. Krowe

    Canada cannot possibly be safer than the US because the US is the bestest best at everything. Plus they're socialist, dont'cha know.

    1. J. Frank Parnell

      Not only socialists. They don't own handguns and they use the metric system. Talk about a lack of personal freedom.

    2. Jasper_in_Boston

      No open carry. How could Canadians possibly be safe without open carry to intimidate immigrants and other suspicious-looking people?

  4. J. Frank Parnell

    Vacationed in Belize in early summer. It was good, the locals were good about masking (better than the locals back home) and everyone employed in the tourist industry was vaccinated. Never felt safer than on the flight back home knowing everyone on the plane was fully vaccinated and had just passed a Covid test at the airport.

  5. rational thought

    Anyone know if this sounds like omicron.

    I have only one symptoms. Sweated and was hot all last night but otherwise felt fine . No cough aches etc . Maybe just a slight scratchy throat. And I am almost never hot . Turned temp down to 65 and still hot and sweaty which is very abnormal for me.

    Feel fine now except still a bit hot.

    If anyone read my prior posts still struggling with whether to try to fly to see my mom who is not doing that good. If I have covid , cannot go. If I do not , seems a huge chance of getting it traveling now as , if 10% of people in plane and airport have it , how easy is it to catch? And infecting my mom is not something I want to do.

    But also a chance that , if I do not go soon, she just might pass on before I can go . And other medical issues make any travel now quite difficult for me anyway.

    I just do not know what to do.

    1. Jerry O'Brien

      I don't know about those symptoms. But I think if you've been vaccinated and got a booster shot, and you get a negative result from a quick test, you should grab some good N95 or KN95 masks and go.

    2. golack

      If you are fully vaccinated, then wait a few days (5?) if you can. If you feel better, than it's cleared, and you're safe to go. If you feel worse, than you wouldn't get to see your mother anyway. Get a Covid test too--but you might not hear back for more than a few days. If a home test is available, get a pack (or two). You might need to make plans to isolate yourself when visiting too.
      When traveling, best to use a N95 mask, or equivalent (without a vent for exhalation). Yea, a bit of a pain, but the tight seal means you'll be protected more as will others around you. Have a your regular masks handy too.
      I wish you and yours well.

    3. iamr4man

      We canceled our trip to New Jersey based on having the same trepidations regarding traveling right now. We were going to visit family we had seen in September so not as urgent. In your case I guess I mostly agree with Jerry O’Brian but I would also take into account the airport you are traveling from and to. In our case it would have meant being in the Newark airport and that place is a hot mess. If I didn’t get it there I’d be surprised.
      Do you have a fever? If so, you might have the regular flu and you should still not go.

    4. Krowe

      Night sweats are an Omicron-specific symptom. Get tested ASAP.

      (I always worry about that particular symptom for other reasons, so it really caught my attention when docs associated it w/ Omicron)

      1. rational thought

        Get tested asap is what I would like to do but seems impossible.

        Just spent nearly an hour trying to get an appointment that is reasonable and no dice.

        Saw one place that was convenient near me and Google says available. After half an hour of navigating their website and registering and putting in a bunch of personal info and creating user name and password , I get to end and find no appointments actually available there at all. And only thing available is over a half hour drive away and you have to sit in car in a long line over an hour which would be real difficult for me medically. And not available until the 16th! What good does that do me? And why can't they tell you nothing available until after you spend half an hour registering?

        This is just like trying to get my first vaccine appt which took me over a week and over 1000 tries. Such a messed up system.

        Funny thing . When I put in a password I typed Thiswholesystemstinks×1000. But that was already taken!

        1. KinersKorner

          The scratchy throat and fever sounds like The O. See if you can find a rapid test. Take it when your symptoms clear. Best bet for neg which would mean you may still have the virus in you ( a PCR would pick that up) but the rapid won’t. To pass your viral load would be down were you are no longer contagious. Listen to Andy Slavits latest in the bubble podcast. He has a Dr on that explains it very well.

      1. rational thought

        As I explained in my post yesterday , other medical problems make it very difficult and painful for me to sit much ( although finally improving after 2 years ) so driving anywhere of any distance is out.

        And this is from ca to fla so no way. There is a small chance I might not be able to make it all the way to fla flying and get stuck at connecting city if I cannot take sitting any more . But trying to drive myself all the way - 100% could not make it if my life depended on it.

        And another concern I have is the messy airline situation with cancelations and delays. Looking at schedules , I think I can barely handle a trip with a connecting stop midway ( giving me a sitting break ) if both trips are on schedule and the sitting time is only the schedule. If something caused a delay where you had to sit on plane an extra 2 hours, I would be in trouble.

          1. rational thought

            I have checked out amtrak years ago for travel from California to fla . Ridiculous options requiring going through out of way cities and a very long trip.

            It would clearly be possible to have a reasonable alternative train option for cross country travel but usa does not have one .

            In terms of avoiding covid , I could

            A) fly out of small airport after half hour taxi ride and then sit in a plane for 8 hours or so fully masked with a real good ventilation system

            B) have to get to downtown LA and crowded poorly ventilated union Station. To take a train trip lasting days where, even if I have my own compartment, with a window open ( in winter?) cannot mask all the time and have to leave to go to the bathroom and have to eat meals . And train does not have great ventilation system .

            Option A still clearly seems better.

            1. cld

              Probably is, but I think you can get your own bathroom on some Amtrak trains.

              And in the south it's tornado weather, natural ventilation!

    5. D_Ohrk_E1

      Just a fever isn't much of a symptom to make a diagnosis of Omicron. Any infection causes fever. What is the positivity rate in your area? Do you wear N95/KN95/KF94 masks regularly? Did you meet with a group of people w/o masks because everyone had been vaccinated and boosted, giving you a false sense of security?

      As for flying, it depends on what airlines you're flying and where you're flying from/to. You can use TSA airport workers as a proxy to the level of infections by airport -- https://www.tsa.gov/coronavirus -- and Flightaware -- https://flightaware.com/live/cancelled/ -- to check for level of cancellations at airports you're flying out of and into, giving you a sense of routes that are, ahem, plagued by infections.

      1. rational thought

        I am in Los Angeles. High number of cases and positivity rate high but not as high as other places as schools here test a lot . Both airports are smaller and hopefully as low risk as possible.

        But really high risk now everywhere. I

        And I have always worn kn94 masks. Most comfortable to me even more than cloth. And I have been very careful , partially because my medical condition limits how much I can do anyway. Only way I got it is maybe at drugstore picking up prescriptions or a brief stop at my office , both times fully masked.

        But , if prevalence really is 15% and 10% of people on plane and in airport are infectious, hard to believe any mask is really going to protect you effectively.

        1. D_Ohrk_E1

          Considering how hospital workers all wear masks and do relatively well in escaping infections in general, I'd feel really good about wearing an N95/KN95/KF94 mask on a flight less than 8 hours long.

          But it seems like you have a very low personal risk tolerance, so, I think you've generally answered your question.

          I imagine there are few things would make a parent more miserable than to see their child die while they're still alive. Zoom meetings.

          1. rational thought

            My concern at this point really is not getting covid myself . In a way I almost want to get it now while my booster is less than 3 months old . I expect that if I somehow do not get it now in this wave, I will get it next few months or next winter at least. So maybe now is the best time for the inevitable. I did not feel that way before omicron.

            But I really do not want to be THE ONE who gives covid to my mom , even if it probably is inevitable there too. And we are wondering if maybe what she is having now is covid , even though she has tested negative.

            Too many reports of clear or strong suspicion of false negative on tests, including pcr, with omicron. Just an hour ago , my brother, who we thought was sure to have covid , got back a negative test result. He traveled in a car for hours with others , unmasked, who all ended up testing positive and all but one are sick. He is sick with mild covid like symptoms at same time and yet he tests negative for covid? Just seems hard to believe that he coincidentally got the flu at same time everyone he was in the car with got covid .

            Not sure we can trust the pcr tests as much with omicron. And no shock if a test designed to find original misses a different variant sometimes.

            1. D_Ohrk_E1

              Well, there are two problems w/ Omicron, with regards to testing.

              1. Viral replication and shedding is not in the same area as previous variants and original strain, early on. Swabbing of nose is less reliable than of the throat, for Omicron. See preprint from South Africa: https://bityl.co/ASfg
              2. Some molecular and antigen tests may be ineffective at finding Omicron b/c the target they were checking has mutated. FDA has a rundown of this: https://bityl.co/ASfW

              But, if you think you have Omicron, think a week ahead. In one week, you won't be infectious. Plan accordingly.

    6. Atticus

      I've had night sweats several days in a row last week into the weekend. (Along with mild cold-like symptoms.) Pretty sure it was covid but never got tested because I couldn't find a test. I actually have an appointment this morning, now that I feel back to 100%. Many of my friends and about half of my kids' friends have had it just over the last few weeks. Everyone had very mild symptoms, if any at all.

  6. rational thought

    On Kevin's point, travel restrictions are pointless now , in or out and whether that nation has a lot of covid or not.

    With the number of omicron cases already now in the USA, if we allowed unvaccinated untested travel from the nation with highest covid cases, still changes almost nothing.

    Travel restrictions might have a point when you are trying to prevent a wave from starting. Once it is in fill swing and the virus is prevalent, they are pointless.

    From a personal risk standpoint, if you are trying to be one of the lucky few not getting infected before herd immunity, it is simply TRAVEL itself that is risky , not travel to Canada per se.

  7. BriPet

    I remember two years ago, I had a medical appointment, they called the day before, and was asked, “have you traveled to a high transmission area?” I looked at the phone and said, “We LIVE in a high transmission county!”

    1. Spadesofgrey

      Lol, like masks are relevant. Many "non-conservatives" complained about masks during the Spanish flu. Finger snaps would do you well.

        1. rational thought

          Cld,

          Actually, spades is correct here. You want one. OK. The most prominent anti-masking organization was in San Francisco and was headed by Mrs. E.C. Harrington . Who also headed the women's progressive non partisan organization. And was a prominent labor and women's rights activist. Self described as a member of the union labor party when registered to vote, of which she was the first on sf ( also first to pass the bar and practice law).

          Not hard to confirm. I just Googled oppenents of masking in Spanish flu and first hit.

          But, as usual, have no clue what spades is saying with " finger snaps ".

          Spades,

          Am I just out of touch with some hip references you make that others get? Or are you being deliberately obscure and not expecting us to understand ? Or are you just occasionally throwing nonsense words in just to play with us?

          1. Joel

            It's a troll. It doesn't have to make sense. It just leaves its droppings to get attention. Please don't feed the semi-literate anti-semitic troll.

  8. Justin

    I disagree with Mr. Drum. Our current dose of suffering and illness is due to some damn fool traveling from somewhere in probably South Africa to Europe and beyond. What’s wrong with asking people to slow down in the midst of this outbreak?

    1. rational thought

      I think Kevin's point is that it has no purpose TODAY . Not that it would not ever had any purpose. If you could institute a hard travel ban before that virus gets here, and thus stop it getting here, maybe that could have worked.

      But I doubt it anyway . First , you have to be aware of the existence of that variant before it can get to the USA in order to stop travel. But very likely some cases had already traveled from south Africa to usa before we even had first reports of the variant to know about it. And note if we immediately ban travel from any nation that reports any possible concerning variant, we give them an incentive to not be honest. And we are not even positive it actually originated in South Africa. It is even possible it first arose in usa but , by random chance, in a group where it spread slowly. But managed to travel from usa to s Africa and was noticed there first .

      And , if you want to even have a chance, it has to be a true hard sudden travel ban. No announcement in advance. No exception for us citizens. And you must also ban travel from any nation that does not also ban travel from the affected nation too. So ban on most of the world .

      And how long? For something like omicron which clearly is way too contagious to ever stop and will become endemic at lower but still significant levels , anything other than a permanent ban just delays your eventual wave.

      1. Justin

        Nothing is worth doing today. It's always too late to take preventive effective action. No use closing the barn door after the horse is gone. I get that. And I get that no one really wants to ever have travel restrictions since they affect tourism.

        Advising people to skip travel is not the same as cancelling flights and locking down. These travel bans / restrictions are constantly misrepresented as bans when they are really advisory. Except for China, of course.

        BEIJING, Jan 12 (Reuters) - China ordered on Wednesday the suspension of six more U.S. flights in coming weeks after a surge in passengers testing positive for COVID-19, taking to 70 its cancellations this year in a schedule that had already been cut back drastically.

    2. rick_jones

      What’s wrong with asking people to slow down in the midst of this outbreak?

      It might make Kevin look bad when he takes his next on-a-whim trip.

      1. Justin

        Perhaps Mr. Drum is working off his bucket list. If I had a serious illness I might do that too. He can ignore the advice and take that risk just like everyone else.

  9. D_Ohrk_E1

    It's like watching a coughing man shrink in horror, struggling between coughing fits to call out a stranger who coughs, "You sir, are infectious! Stop coughing this instant!"

  10. Special Newb

    Maybe they we said that to try to keep people from going to Canada and maling it worse.

    IMO travel restrictions are not crazy. We should limit international travel sharply forever. This won't be the last pandemic, and with the internet and VR it's becoming ever less important to do face to face. Certainly folks 100 years ago could stand it.

    1. rational thought

      The idea to restrict international travel permanently is more arguable. I doubt anything will really stop any contagious virus as not going to stop travel completely and it will eventually get here.

      But permanent limits may have a chance of avoiding a virus getting here before you have a chance to hear about it and institute a hard travel ban. Or at least allow it down some to buy time to figure out what to do or develop a vaccine . Or, if the new virus is less contagious than covid but more deadly , to maybe be able to set up a workable test and contact trace system and actually control it.

      Say some future virus is ten times deadlier than the flu but just equally as contagious as the flu . Well, unlike covid which was more contagious, has hard to detect asymptomatic cases , and is so easily aerosolized , this experience has shown we certainly damn well can stop something like the flu if we want to make the sacrifices.

      I think we need to stop worrying and thinking what we can do to stop covid, especially omicron. We simply cannot and , even if it was possible, all those things would have to been done in the past. Now the omicron story is over as to what we can do mostly.

      Time to plan for the next virus which might have different characteristics that both make it a bigger threat but give us a better chance to stop.

      That could be a new crazy covid mutation although I think highly unlikely.

      It could be a new virus actually developed in a lab and deliberately released to cause havoc by some nefarious country or terrorist organization.

      Or it could just be the flu. Say omicron really does turn out to be at level of a cold and, after this big wave , omicron natural immunity is good enough so that endemic level is high but not crazy high like now. So that is something just not worth instituting any restrictions over.

      But we are due for a real bad flu season because after last two years of almost no flu , our community flu immunity is at very low levels. And all the masking and covid restrictions seemed to have minimal success stopping covid but they destroyed the flu . And we really do not need that harsh measures to limit flu. If starting R is 1.3, not that hard to push it below 1.0.

      So stop arguing about what we need to do about covid. Old news at this time. And start talking about the future threats because clearly we are poorly prepared for something which really could threaten civilization which covid never was.

  11. rational thought

    I have checked out amtrak years ago for travel from California to fla . Ridiculous options requiring going through out of way cities and a very long trip.

    It would clearly be possible to have a reasonable alternative train option for cross country travel but usa does not have one .

    In terms of avoiding covid , I could

    A) fly out of small airport after half hour taxi ride and then sit in a plane for 8 hours or so fully masked with a real good ventilation system

    B) have to get to downtown LA and crowded poorly ventilated union Station. To take a train trip lasting days where, even if I have my own compartment, with a window open ( in winter?) cannot mask all the time and have to leave to go to the bathroom and have to eat meals . And train does not have great ventilation system .

    Option A still clearly seems better.

  12. rational thought

    Interesting data from la county today.

    For week ended 12/25, they report rate per 100,000 of 991 for unvaccinated, 588 for double vaccinated but not boosted, and 254 for vaccinated and boosted. First I have seen breaking out boosted.

    And report hospitalization rate is 9 times more for vaccinated and not boosted vs. unvaccinated and 38 times more as comparing boosted vs no vaccination. They also report death rate ratio of 22 times but not clear if that is relative to all vaccinated or just vaccinated and boosted. I think it is boosted which means being vaccinated and boosted INCREASES your chance of dying if you are hospitalized. And we have seen this result other places where vaccine effectiveness is less for death than for hospitalization. Will give my thoughts there in subsequent post.

    Now 12/25 is before omicron became a huge wave and delta was still a small part of the picture especially for deaths which lag. So full omicron picture might show less vaccine effectiveness.

    And have to factor in what seems clear is a major major issue. That vaccinated are simply healthier and less likely to catch covid and die simply because of who they are and not the vaccine . The choice of whether to get vaccinated itself seems to be a major screening factor in separating out the healthy and cautious from the unhealthy risk takers, even without vaccination itself . The evidence seems to be that is a big part and accounts for a lot of the difference.

    So that the disparity between 991 and 558 seems easily explainable just by that alone and maybe double dose vaccine has zero effectiveness by now in stopping infection.

    Plus , if vaccine is preventing sickness only, that should mean a lower % age of cases among vaccinated are confirmed and so true rates for vaccinated are a higher ratio than for unvaccinated.

    Even for 588 vs 254, the difference is not enough to be sure there is a real effect.

    But, for ratios of 9 and 38, just impossible to believe that is all those coincidental effects and cannot be mostly actual vaccine effectiveness.

    So my conclusion is that vaccine and even booster might have some effect in preparing infection by omicron but might have zero effect . But seems clear that it still limits how sick you get.

    And what might be hopeful is that might indicate that actual vaccine antibodies are crap against omicron . Otherwise it could stop infection better. Maybe at best they slow it down a little.

    But the t cells and B cells still work. Maybe the b cells have to adjust the vaccine antibody to account for omicron changes as it sees them. And that takes a little time so you get infected and even mildly sick. But having the vaccine antibody template already, even if it itself does not work, gives those b cells a head start and so they produce the better omicron adjusted antibodies quicker. Quick enough to stop the virus before you get very sick .

    And that means worrying about our vaccine boosted antibodies or natural antibodies from prior variant infection waning or disappearing is not needed. They are not working anyway. It is the longer term immunity that is working for omicron anyway.

    So not sure if boosters for existing vaccine are really requires that often of long term immunity works well enough.

    1. rational thought

      Now why might vaccine effectiveness go down from hospitalization to death?

      Well i suspect there have to be some who have a damaged or very old or weakened immune system. So poor that it simply cannot fight off the virus even if trained by the vaccine. If your immune system is just not good enough to do the job even if it gets advance knowledge by the vaccine, nothing the vaccine can do. They are doomed anyway.

      So, if the vaccine buys extra time for the immune system to beat an infection and win, it weeds out most of those whose immune system is healthy- they do not get sick enough to be hospitalized . The only ones hospitalized with vaccine are those whose immune system is somewhat weak and some of those die.

      While, for those with no immunity, a good number will still get sick enough to be hospitalized briefly , because the lack of a " head start " for a novel virus meant that it took longer for the immune system to figure out . They never were going to die anyway - vaccine or not . But if vaccinated they would be recovering at home.

      Consider the analogy of a bulletproof vest covering the vital areas . A criminal is shooting at a cop. 50% of the time he hits nothing. 25% of the time he hits arms legs etc outside of vest and only 1 of 25 die. 25% of time hits

      1. rational thought

        Sorry posted too soon again and realized messed up the analogy

        So start over and assume a full body vest which covers everything except head as you need to see and breathe.

        The criminal shoots at the cop. 50 out of 100 misses . 40 of 100 hits vest and bruise no hospital. 10 of 100 hits unprotected head and 5 die and other 5 hospitalized.

        Without a vest , 40 hits on vest now hit body . Of those 30 are hospitalized and 10 die. Plus same 10 and 5 with head hit.

        So vest wearing cop has 10% chance of hospitalization and 5% chance of death. No vest 40% chance of hospitalization and 15% chance of death.

        Among those vest wearing cops who are hospitalized, 50% die. Among hospitalized without vest , 37.5% die.

        Did vest wearing cause those hospitalized to die? No.

        And , even if a higher % of hospitalized vaccinated die, that certainly does not mean the vaccine caused that death..

  13. cld

    Covid loses 90% of ability to infect within minutes in air,

    https://www.theguardian.com/world/2022/jan/11/covid-loses-90-of-ability-to-infect-within-five-minutes-in-air-study

    Coronavirus loses 90% of its ability to infect us within 20 minutes of becoming airborne – with most of the loss occurring within the first five minutes, the world’s first simulations of how the virus survives in exhaled air suggest.

    The findings re-emphasise the importance of short-range Covid transmission, with physical distancing and mask-wearing likely to be the most effective means of preventing infection. Ventilation, though still worthwhile, is likely to have a lesser impact.

    “People have been focused on poorly ventilated spaces and thinking about airborne transmission over metres or across a room. I’m not saying that doesn’t happen, but I think still the greatest risk of exposure is when you’re close to someone,” said Prof Jonathan Reid, director of the University of Bristol’s Aerosol Research Centre and the study’s lead author.

    “When you move further away, not only is the aerosol diluted down, there’s also less infectious virus because the virus has lost infectivity [as a result of time].”
    . . . .
    The study, which has not yet been peer-reviewed, suggested that as the viral particles leave the relatively moist and carbon dioxide-rich conditions of the lungs, they rapidly lose water and dry out, while the transition to lower levels of carbon dioxide is associated with a rapid increase in pH. Both of these factors disrupt the virus’s ability to infect human cells, but the speed at which the particles dry out varies according to the relative humidity of the surrounding air.

    When this was lower than 50% – similar to the relatively dry air found in many offices – the virus had lost around half of its infectivity within five seconds, after which the decline was slower and more steady, with a further 19% loss over the next five minutes. At 90% humidity – roughly equivalent to a steam or shower room – the decline in infectivity was more gradual, with 52% of particles remaining infectious after five minutes, dropping to about 10% after 20 minutes, after which these was no difference between the two conditions.

    However, the temperature of the air made no difference to viral infectivity, contradicting the widely held belief that viral transmission is lower at high temperatures.
    . . . .

    1. rational thought

      Everything you think there is a consensus on something covid related, some new study comes out and reverses the concept. Do we really know anything that we can have confidence will last? And this study is not peer reviewed yet and seems to go against what has been thought for a while in many respects, so I would still be cautious about it yet.

      And , if this is true and covid has little ability to spread lasting long in an aeroseloized form, that also implies it must be even more contagious in situations where it does not have to do that.

      So then shopping at the grocery store indoors which has 50 people in it unmasked is not as dangerous as we thought , as long as you make sure you avoid getting too close to anyone. But talking to someone outside from a few feet away , well that is riskier than we thought.

      Since we knew how fast it spread anyway , any change in knowledge of how it spreads which implies x activity is riskier than prior estimate must mean other activities are not as risky .

      Plus note this study was not including omicron. Is it possible one way omicron is so contagious is it evolved something that allows it to last longer? Any study that applies only to pre omicron variants is mostly only theoretical now and has little practical use.

      1. cld

        Shopping at the grocery store isn't as bad as thought, but then standing in line at the checkout may be worse, so it all balances out.

        What struck me was the point about it's sensitivity to humidity, and we don't hear much about it from North Africa or the Middle East.

        Indoors, broadly, is not as bad as feared as long people keep their distance, which is bad news for that guy at the office who just stands there blathering away all day. I always assumed he was a vector of something.

  14. kartoon111

    As a Canadian citizen, may I make a comment?

    When all is said and done, some of us are not terribly concerned when the USA closes the 49th parallel. The lessons of the War of 1812-14 remain: 'the Yankees are not to be trusted, ever again'. This I absorbed as a young child....

    That's the way it is. We are dealing with the pandemic reasonably well, as your histograms show. I do not know any adult who is not 3 shots in the clear.

    Something about stewing in your own juices down south of the 49th parallel occurs but best not said I think,

    Best of luck down there with your criminal anti-vaxxers and coup d'etat people. Its going to get rough and I sincerely hope your country survives this. Its even odds now I would think.

    But on the plus side, during the US civil war, Canadian farmers sold to both sides to their collective enrichment. Have at it if you wish but please, no mob scenes at the border. During Vietnam, refugees were arriving in Toronto at a hundred a day, and they all had their otherworld political spines out.... took years to calm them down and sort out their maleducation problems.

    1. cld

      The lessons of the War of 1812-14 remain: 'the Yankees are not to be trusted, ever again'. This I absorbed as a young child....

      I guarantee there are possibly three Americans alive who have any idea what you mean by that.

  15. rational thought

    Really! Don't they teach anything about the war of 1812 in schools anymore? Is it now an obscure topic.

    I know it is hotly debated on one history site where any 1812 post quickly degenerates into an argument in great detail as to who was to blame for the war and who really won..

    I am not sure if kartoon was being toung in cheek in saying they were taught in schools that the war taught Canadians that Americans were never to be trusted ever again. If your point was something re the ever again and trusted, then I guess maybe you have a point because that I do not really get . It would imply that there was a Canadian identity prior to the war that trusted the USA in some way and was betrayed. ??? I can understand some bad post war feelings by those who really only first came to think of themselves as Canadians because of the war. But what aspect did they trust the USA on prior to the war which was betrayed? Basically the USA and England were still enemies prior to that war anyway and did not trust each other .

    And interesting that he calls it the war of 1812 - 1814. Of course the cute fact is that war we call the war of 1812 did not end until 1815 with the most well known battle being after the peace treaty was signed ( New Orleans ). But , as that was a British defeat , most British want to contend that , as after peace signed ( although neither side knew that ) , it does not count as part of the war.

  16. damgo2

    CDC is recommending this because this group has a mandate to rate countries based on Covid risk. Obviously Do Not Travel makes no sense in context but that's outside the scope of their job, and giving realistic vs. ultra-cautious travel advice is not an institutional priority at a higher level.

    On travel restrictions it's all political fear. No politician wants to open themselves up to getting attacked for letting foreigners bring Covid into the country. And it's very low cost to impose restrictions on foreigners. It's no coincidence that these objectively-pointless border controls almost always exempt citizens.

Comments are closed.