Another week, another impressive milestone. This week the US crossed the line for less than 10 cases / 100,000 people per day on the seven-day average. Beyond cases, the positive test rate is down, as are hospitalizations. Week over week, we continue to see the effects of the vaccination campaign.

SF General announced for the first time since the start of the pandemic they didn't have a single Covid-19 patient in house.

In the first week of vaccinations for 12-15-year-olds, over 600,000 got their first shot. There are only 16 million people in that cohort, so that's a great start. As a country, we've vaccinated over 40,000 people per hour since January 20th.

On top of that, over 60% of adults and 85% of seniors have had their first shots.

This week we got results from the first mix and match vaccination study. In this trial, recipients received one dose of the AstraZeneca vaccine and one dose of the Pfizer. The patients ended up with higher antibody levels than if they had just received two doses of the AstraZeneca by itself.

Overall there have been some concerns about the efficacy of the AZ vaccine against some of the newer variants, so this is essential data showing that a single shot of a different type would bring it up to par.

On the topic of boosters, the first real-world data was shown for the newest variant of concern, 1617.2. The results of that study showed a slight decrease in overall effectiveness against the vaccines but not much. More concerning was that if you only had 1 of the 2 shots for the two-dose vaccines, it had a pretty significant drop-off. Make sure you get both your shots.

In surveys of those who haven't been vaccinated yet, many said that they want to get vaccinated but can't get time off work / are confused about how to get one or cost. Overall we will continue to need to improve education and access to get the remaining over the line.

The US is also starting to focus on how we can help the rest of the world. The Biden administration will be exporting 20 million doses of an FDA-approved vaccine by the end of June. This is on top of the 60 million doses of AZ they are sending abroad.

We will continue to send more and more supplies abroad. We are already helping to set up more factories in other counties.

Booster shots have been in the news lately. The short answer is we don't know when / if we'll need booster shots. To date, we haven't seen any actual drop-off in the antibodies in the original cohorts from the Phase I studies nearly a year ago. The Phase III studies from last summer involved tens of thousands of people, and they will be our best early indication.

Also, we have more and more data that even though some variants have some immune evasion, it doesn't look like any have enough to really matter. Israel and the UK have had breakouts of 351, 117, and 1617.2 and haven't seen their case counts jump.

I've been getting questions about what to do if you have kids under 12. Unfortunately, there isn't great consistent guidance right now. From what we've seen to date, kids under 12, even when they do get Covid, tend to not have particularly bad infections. There are some exceptions.

Vaccines for under 12 won't be available until the fall, so the summer is an open question. Given what I see in terms of the trajectory of the overall epidemic, I think that the overall case count will be low enough that it's a bit of a moot point. In some parts of the US, we're close to 1 case per 100,000 people per day and continuing to drop.

As I said last week, Covid is ending, and we should start acting like it. Case counts have been on a steady decline for six straight weeks. Of the top 50 metro areas by population, only 1 has an R over 1 [New Orleans]. California reaffirmed that it will lift all restrictions on June 15th.

Barring some colossal spike or complete immune escape, I'll probably be ending these updates sooner rather than later. As always, please reach out if you have any questions or concerns; I'm happy to chat.