Thread by @DrJayVarma

Having now read the one study on intra-dermal #monkeypox vax & spoken with a few folks more knowledgeable than me about immunology, some thoughts below on @FDAgov @CDCgov approach

/1

https://twitter.com/US_FDA/status/1557088599727800322

Level of neutralizing antibodies from intra-dermal should be equivalent to subcutaneous. This switch should both expand vax supply & increase protection in those most at risk - critical goals right now.

/2

We still do not know for sure:
-how much protection comes from antibody response vs. other forms of immunity
-whether the total immune response varies by subcutaneous or intra-dermal

/3

As with standard subq vax administration, we *really* need real-world effectiveness studies: how much does vax prevent infection &, in those infected, reduce severe disease?

These will take months, but need to be in place now for both for post-exposure & pre-exposure use.

/4

Ideally, these real-world studies would also involve use of ACAM (smallpox vaccine).

Is it possible for @CDCgov to evaluate SQ Jynneos vs. ID Jynneos vs. ACAM as both pre- and post-exposure prophylaxis?

/5

Given totality of evidence & acute vax shortage & urgency, I support the intra-dermal approach as long as we proceed with getting the best quality evidence we can as above.

Next big concern is implementation.

/6

Mass vax campaigns are like industrial manufacturing: every step in the process needs to go perfectly for it to work & even small error rates at one step can result in big problems.

/7

Staff in TB clinics give intra-dermal injections (PPD) all the time. Most other vaccinators do not. They need to build confidence so, when they do 50 in a day, they do it right every time, especially since not much room for error with lower dose vaccination.

/8

The syringes need to be in sufficient supply and able to withdraw vax from bottle accurately. From folks I’ve talked to, seems this should be easy with #Jynneos. (Was not so easy with #COVID19 vaccine).

/9

Itching & redness at site of injection will be a big issue. BUT with vax targeted to those at highest risk & other interventions for prevention possible, I’m not too concerned about vax acceptance. I’d be more concerned if we were encouraging entire US population to get it.

/10

Note that I support current intra-dermal approach based on assumptions:
-It’s not possible to increase Jynneos supply dramatically
-Other approaches (behavior change; testing & tracing) will not stem this outbreak alone

/11

Many others, such as @PrEP4AllNow, can speak more to increasing vax supply. Per their research, there is more administration can & should be doing.

/12

Mass screening & outreach could also drive incidence down, but depends on tests that use alternative specimen types (OP, saliva) or provide rapid results from skin. Until those available, mass testing not practical for outbreak control.

/13

In sum, I recommend those at risk get vaccinated with either intra-dermal or subcutaneous.

But really hope we get the data comparing effectiveness & develop tools to supplement vaccination.

/end