Thread by @MonicaGandhi9

These days in U.S., asked what end of epidemic would look like & I wanted to explain why COVID - once controlled- will be more like measles (where public doesn't think about every day) than influenza (where public does think about in winter). COVID has highly effective vaccine

like measles does - the effectiveness of the measles vaccine is high like the effectiveness of the COVID-19 vaccine - one dose 93% effective and two doses 97% effective per original studies. We give measles vax
fda.gov/consumers/cons…).

two doses in childhood & then high exposure populations like healthcare workers/international travelers often given booster - schedule is here. We have already discussed that T cells from measles vaccination last a long time -remember paper
cdc.gov/vaccines/vpd/m….

showing the 34 years of CD4 cells (T cells) and counting from getting the measles vaccine years earlier? Okay, so what do we mean by "control" of an infection. Control means that the vaccine is so effective that cases are kept to very low levels so no
academic.oup.com/jid/article/19…

more disruption of normal life. As Dr. Fauci told us, we will get to "control" of this virus: seems hard to believe, but someday public will not be aware of cases/hospitalizations from this virus but, like measles, ID doctors will be aware & treat.
washingtonpost.com/health/coronav…

What I mean by that is that we (ID doctors) see measles in this country but they are in small outbreaks of unvaccinated people or among unvaccinated person who travels to place where measles at higher rates (more vax hesitancy in Europe for instance). But public aware of flu

every winter because 1) vaccines required yearly for now since not a global nor highly effective vaccine; 2) importantly, influenza is a MUCH MORE MUTABLE virus than coronavirus. Influenza, measles, coronavirus all what we call "RNA viruses" which means the genetic material

they carry is RNA instead of DNA (DNA viruses are like herpes virus or varicella zoster virus causing chickenpox, shingles). RNA viruses mutate more than DNA viruses but influenza is extremely mutable (mutates very quickly). Measles actually more mutable than coronaviruses but

once you get it to low levels, it simply doesn't have chance to mutate: that is where we are with measles in the world which is why we don't adapt vaccines (nor worry about variants). Coronaviruses are so stable, don't like to make mutated copies, they have been called

"DNA virus wannabees" (which is something that would make an ID person giggle knowingly). More technical read on this here. So, when is last time you worried about measles? Not much but I think about it a lot & have seen sporadic cases. COVID control
journals.plos.org/plospathogens/…

achievable, US nearing. Remember, we don't screen people's noses for measles if vax & asymptomatic; won't do this in future for COVID. If someone sick must assess for vax breakthrough on COVID as CDC indicates. Measles (&eventually COVID): Unvax'd protected by vax'd.

Vaccine and natural infection both produce long lasting memory B and T cells which is also helpful for imagining life without need for boosters for long time:
leaps.org/booster-shot/

Someone asked me after thread if measles vax updated for mutations- no, it is not updated. Same vaccine! And yes, the more people who get vaccinated the better for COVID including children when safety data out (can still have normal school for kids in fall with low cases though)

One more ID fact to explain why COVID more like measles: Influenza has massive animal reservoir (swine, pigs, duck, birds, waterfowl where mutations are ongoing) in close contact with humans. Once COVID controlled, will become rare like other vaccine-preventable diseases *measles

See frustration about setbacks (e.g. Israel) & variants (delta). We have never tested for a virus like this before; few hospitalizations in Israel (in past) is all that would have signaled minor outbreak before. Will do thread re; eradication vs elimination vs control on weekend

When I do thread, we will discuss how we won't eradicate (smallpox only one) & likely won't eliminate in region, but that control achievable & Israel/US/UK are not out of control by long shot & living with a control is possible without disruption; let's take long view of ID!

Wrote this thread a long time ago to tell us about what a controlled infectious disease looks like (not yet there with delta, obviously), specifically measles. Measles was first described in 9th century and was even more contagious than delta SARS-CoV-2
cdc.gov/measles/about/…

1st vax developed in 1963 but exposure prior to that (if not fatal) gave lifelong immunity; we even ask patients to this day if born before 1963 before deciding to give measles booster (because likely to have been exposed to measles naturally & immune)
historyofvaccines.org/timeline/measl…

So, this time we developed a vaccine for a terrible pandemic in just over 6 months. Described March 2020, first press release from Pfizer/BioNtech of highly effective vax Nov 9, 2020 so we have tool to get immunity up worldwide without natural infection if we choose to give out

vaccine with #globalvaxequity. In meantime, delta very transmissible, leaving much immunity in its wake, sometimes with tragic preventable suffering/death, sometimes boosting immune response of those with prior infection or vax; immunity controls a virus
nature.com/articles/s4146…