The Minnesota briefing was thankfully brief on Friday. The most notable messaging was more guilting and shaming of people about going to Sturgis or somehow being responsible for staff who work in long-term care facilities becoming infected and bringing the infection to residents. It was amusing to watch them try to explain why Sturgis=Bad, while large Protest (riots) Gatherings=Just Fine. They are just desperate to come up with anything to terrify people. I just want to yell–“What happened to all the cases from the rodeo? What happened in Worthington? What happened in St. Cloud? What happened everywhere else you tried to scare us about?” They were asked about Sweden and just avoided the question with some mealy-mouthed meanderings. It is apparent to anyone with a brain, and that may be the problem with this group, that Sweden took the right approach. Far less damaging to their economy and society and leaving them free to live relatively normal lives, without, horror of horrors, wearing masks everywhere. Technical difficulties cut the briefing short, the several minutes of silence was as enlightening as hearing staff dance around the truth.
The research today includes a piece on just about every topic of current interest. First up, researchers in Germany discover that the lockdown had little to do with the tailing off of the epidemic in that country, because it had already begun to slow by the time those measures were put in place, due to voluntary behavior changes by citizens. (SSRN Paper) They also discuss the difficulty of assessing the effect of mitigation of spread measures given variation in testing strategies and levels and missing information on actual infection numbers.
One interesting piece of research was the European Center for Disease Control putting out an evidence review on children and coronavirus designed to help provide guidance for schools, among other things. (EC Review) Everybody is reviewing the same research, so they should come to the same conclusions. The background to the report notes that as in the US, many European countries closed schools in response to the epidemic, although most are open now. The background also recites all the known harms to children from not being in school. The key messages of the report include: children are much less likely to become infected than adults are; they are more likely to have mild or asymptomatic illness, which could be viewed as bad if they are infectious and undetected; they are much more likely to become infected at home and unlikely to cause child-to-child or child to adult transmission in school settings and that outbreaks appeared uncommon in re-opened schools. It isn’t that there is zero risk; it is that on the balance of harms and benefits, children are far better off in school. But our political leaders have shown themselves to be incapable of even the most basic risk/benefit analysis.
And here is a story from the Wall Street Journal about why it is safe to open schools. (WSJ Article) Again, a restating of the harm to children from missing school, with the disproportionate impact on minority and low-income children. A balanced presentation of evidence and experience from places where schools are open. I will shortly do a bigger post on the all the long-term harms identified in the Journal of the American Medical Association editorial I referenced earlier in the week. Teacher unions and politicians who keep kids out of school should be held personally responsible for this damage.
Another current hot topic is use of face masks. Here is the UK’s public health service’s review of the evidence. (UK Review) Same story, weak evidence at best for an effect on transmission. The review notes that other reviews relying on modeling or observational studies are not using as rigorous a body of evidence as those relying on actual trials.
The hundredth paper on antibody responses. (Medrxiv Paper) These authors focussed on 49 patients with mild or asymptomatic infection. They found a wide variation in antibody response, in six cases none, and an inconsistent neutralizing effect. They also found evidence of cross-reactive responses from prior seasonal coronavirus infection. The weakness of failing to also examine T cell memory is apparent, and I now am always wondering about the adequacy of the assays used.
And another antibody prevalence study, this time from Connecticut, which like many Northeastern states had a pretty good epidemic in the spring. (Medrxiv Paper) This was an attempted randomized sample of around 500 residents. While around 32% said they had at least one symptom of coronavirus, the prevalence was only 3%. As a side note, an extremely high 97% percent said they wore masks at least some of the time, and most took other precautions. What is the point of a mandate when people appear capable of making their own decisions about risk control.
More research on the physical nature of transmission in this study. (Medrxiv Paper) The authors attempted to simulate exhalation and track the path of droplets of all sizes, including aerosols. They found a particular effect of relative humidity on how far a particle could travel and suggested relatively long lifetimes under certain conditions.