HETEROLOGOUS VACCINATION (means one dose of one type of vaccine & 2nd dose of another type of vaccine): Paper came out today (mix & match) that finally looked at J&J + mRNA vaccine together; 1st let me tell you about studies in past which examined this with AztraZeneca + mRNA
Study from the UK (Com-CoV) looked at an adenovirus DNA vaccine (examples are AztreZeneca (AZ) J&J, Sputnik V - in this case it was AZ) and the mRNA vaccine (only two examples are Moderna + Pfizer, in this case studied Pfizer) 28, 84 days (4,7 wks) apart
Did combination in the 4 ways (Pfizer/Pfizer, AZ/AZ, AZ/Pfizer, Pfizer/AZ) and found that the best combination in terms of both neutralizing antibody titers AND T cells was AZ then Pfizer (so adenovirus/DNA then mRNA). 2nd study from Spain, summary here
Looked at AZ vaccine followed at least 8 weeks later by a Pfizer vaccine (look at that nice spacing interval between doses) and this combination triggered higher antibody responses than AZ vaccine alone (don't see T cells measured). 3rd study from Germany
measured cellular immunity and antibody responses with different mix/match regimens of AZ, Pfizer and Moderna (duration between doses was shorter for two mRNA vaccines 4 weeks then those that used AZ ~ 11 weeks). Strongest antibody & T cell response with AZ then mRNA like in UK
Study today from NIH looked at combinations of J&J, Moderna and Pfizer (2 shots apiece, homologous or heterologous, doses >= 12 weeks apart). Seen before: 2 Moderna doses when evaluating homologous combos gave he highest neutralizing antibody response
Of heterologous combos, rise in neutralization antibodies greatest for those who got the J&J followed by an mRNA vax(compared to two J&J doses). Table below- important to note T cells not reported here but consistent with previous data that DNA followed by mRNA more immunogenic
Biggest limitation? T cell immunity not measured (although T cells needed to help B cells produce antibodies); clinical outcomes not measured; neutralizing antibodies don't tell whole story. All combos gave titers that are likely protective (>100) but J&J + mRNA strong combo

• • •

Missing some Tweet in this thread? You can try to force a refresh

Keep Current with Monica Gandhi MD, MPH

Monica Gandhi MD, MPH Profile picture

Stay in touch and get notified when new unrolls are available from this author!

Read all threads

This Thread may be Removed Anytime!


Twitter may remove this content at anytime! Save it as PDF for later use!

Try unrolling a thread yourself!

how to unroll video
  1. Follow @ThreadReaderApp to mention us!

  2. From a Twitter thread mention us with a keyword "unroll"
@threadreaderapp unroll

Practice here first or read more on our help page!

More from @MonicaGandhi9

10 Oct
"Dr. Gottlieb sees Covid’s ‘pandemic phase’ ending when antiviral pills, kids' vaccines available": wanted to explain from infectious diseases principles what @ScottGottliebMD means by this which makes sense to me
There was a time between alpha and delta when there was talk of herd immunity - where the vaccinated or immune would protect the non-immune. But delta is so transmissible, that it changed the equation & the dialogue
Now "control" and "endemicity" being discussed (as in article I wrote for @washingtonpost above) where control is a place where the virus is brought down to low circulating levels but outbreaks still seen among unvaccinated & ongoing vaccination of susceptible (kids) needed
Read 14 tweets
8 Oct
California's COVID cases are lower than in other states that are more vaccinated. Why? - Agree mix of natural immunity plus high vaccination sfchronicle.com/bayarea/articl… via @sfchronicle
Some of the statistics on our natural immunity (38% by end of winter surge) + vaccination rates are in this article I wrote yesterday:
Where are we with our rates of immunity overall? Dr. Rutherford at UCSF estimates 84% needed for delta & every state is different with rates of natural+vax before delta but delta led to more vax + many more cases
Read 5 tweets
7 Oct
San Francisco to lift some mask rules Oct. 15, other counties lay out criteria (metrics good for public health dictums; increases trust) sfchronicle.com/health/article… via @sfchronicle
Good article from @j_g_allen on why the CDC metrics probably not best criteria though...
Here are criteria for Bay Area
•Moderate (yellow) COVID-19 transmission tier >=3 wks
•COVID-19 hospitalizations low/ stable (health officer judgement)
•80% fully vax'd (boosters not needed)
OR 8 weeks since EUA for 5-11 year old vaccine.
Probably strictest criteria in US
Read 5 tweets
7 Oct
As FDA weighs decisions on boosters for Moderna and J&J this month, remember this comparison effectiveness study from CDC last month: Moderna 93%; Pfizer 88%; J&J 71% effective against hospitalization in delta era. Moderna is 100 micrograms (3 times dose
of Pfizer which is 30 micrograms) & also given at 4 weeks instead of 3 weeks apart. Vaccines usually given at least 1 month apart (& more) so 3 weeks very short for duration. Moderna dose of 100 micrograms may be too high for 12-17 years for toxicity
Dose for 5-11 year olds that Pfizer submitted to FDA for EUA today is 10 microgram dose so adjusted downwards for younger people (but still given 3 weeks apart- latter may be too short for maximal immunogenicity/safety). Would love vaccinologists' thoughts
Read 6 tweets
5 Oct
Written with @JVergales. Many ways to keep children safe in school, most notably high adult vaccination in 2021 but many mitigation procedures shown beneficial in 2020 (masks, ventilation, testing exposed, etc.). Quarantine without test-to-stay likely least effective
Quarantining is by no means a new tool to curb the spread of illness. Descriptions of periods of isolation for those who may have come into contact with a highly contagious disease date to the 14th century as various plagues ravaged parts of Europe.
Ships sat for 40 days at ports until all contagion was thought to be cleared and the name stems from the Italian words quaranta giorni which mean 40 days. US used quarantine throughout the 19th and 20th centuries when epidemics of polio, tuberculosis
Read 7 tweets
4 Oct
Were California county mask mandates effective against delta? Here's what the data says- analysis from @SFGate that tells us what most of already know: "Health experts largely agree that vaccines are a more effective intervention than masks". Agree
Most notable comparison is between Orange County (no mask mandate) & LA (yes mask mandate) but same rates of hospitalizations (OC had fewer cases). Masking & behavior are human variables but strong conclusion can be made "regarding vaccine efficacy against hospitalization"
Masks important tool to lower disease prior to vax but countries that messaged optimism in vaccines as way back to normal (Wrote this piece FEB '21) & did not have this much misinformation had much better vax rates; White House should message optimism now
Read 5 tweets

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just two indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member ($3/month or $30/year) and get exclusive features!

Become Premium

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!

Follow Us on Twitter!