2021-08-04 General


This preprint says that injecting REGEN-COV (a monoclonal antibody treatment that you might know by the name of the company, Regeneron) into people who have been exposed to COVID-19 prevents developing a symptomatic infection with efficacy of 92.6%.

This is a BFD. Before, they had to give it as an infusion i.e. the patients had to be set up with an IV drip and sit there for like an hour. Hospitals generally had infusion clinics, but they were usually set up in the cancer wards. You really don’t want immunocompromised cancer patients sitting next to COVID-positive patients for an hour.

This study says that, instead of an IV drip, injecting the drug works just fine. This is awesome: now, if someone is known to be exposed, they can be given an injection of REGEN-COV, breaking the chain of transmission!

It might be cost-prohibitive: as far as I can tell, it costs a few thousand dollars per treatment in the USA. It might be cheaper in Canada.

It is true that hospitalization costs in the tens of thousands of dollars, but only 7.8% of the placebo group developed COVID-19. Still, it will be really useful in some cases.

This article says one study shows that heparin — a blood thinner — can help moderately sick COVID-19 patients. However, a second study shows that you have to be careful not to give full-strength heparin to patients who are already on life support: it can make them worse.


This preprint out of England describes the latest round of a national swab survey. It says that the vaccine effectiveness was:

  • 64% against asymptomatic infection, 83% against symptomatic infection between 20 May 2021 to 7 June 2021, where 78.3% of sequenced tests were Delta;
  • 49% against asymptomatic infection, 59% against symptomatic infection between 24 June to 5 July 2021, where 100% of sequenced tests were Delta.

Note, however, that this was not a randomized study, so the method they used to calculate the effectiveness was a bit more hand-wavy. In fact, they did a secondary analysis of the latter group and came up with a revised value of 75% against asymptomatic infection in the later period when they could look at the medical records for vaccination status (instead of self-reported). That doesn’t sound nearly as bad as 59%.

Also note that not everybody invited to send in a swab did so, and that participation has been declining. At the beginning of the multi-period study, in May 2020, 30.5% responded. In the most recent period, only 11.7% participated.

Also note that the “unvaxxed” bucket included people who had already had an infection.

The paper did not break down the effectiveness by vaccine brand.

The study also found that vaccinated people had lower viral loads, which is good.

Here’s a mass media article on the study.


This large study of children age 5 to 17 in England found that only 0.67% of them tested positive between Sep 2021 and Jan 2021. Of those, only 1.8% had symptoms lasting longer than 56 days.

Recommended Reading

This article debunks a lot of the misinformation about COVID-19 vaccines and women’s health and fertility.

If you want to travel and have mixed vaccines, this article gives information about who recognizes yours and who doesn’t.