First look at the only randomized trial of a booster vaccine data (Pfizer) today cdc.gov/vaccines/acip/…
95% efficacy vs symptomatic infections, consistent across all age, sex, race, ethnicity and comorbid condition subgroups
Benefit seen very early
Side by side event curves for the original Pfizer vaccine trial vs the Booster trial
You can see the curves diverge about a week earlier with a booster, ~14 vs 7 days, which aligns with much faster induction of neutralizing antibodies
Take a look at the data for people age 18- 55 in this, the only randomized trial (and N>10,000) of a booster vs placebo. Let's make believe @CDCgov that only people >age 50 "should" derive benefit vs symptomatic infections. The primary efficacy endpoint of all vaccine trials.
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The problem with vaccine waning 4-6 months later was 1st recognized in Israel in July, confirmed by more than 10 reports, and occurs with all vaccines. Protection is fully restored (or even exceeded) by 3rd (booster) shots.
The >95% vaccine efficacy vs hospitalizations and deaths for mRNA vaccines in the Phase 3 randomized trials also waned. Protection is fully restored to this high level by 3rd (booster) shots.
How long will it last?
Nobody knows for sure yet.
But let's hope Israel is right again:
"By analyzing the antibody levels, researchers have concluded that the third shot could be effective for 9 – 10 months, or even longer." timesofisrael.com/pfizer-booster…
Addressing the anti-vaxxer BS about vaccines not preventing transmission. It's not 0|1. 1. Recent Dutch study during Delta
"Effectiveness of full vaccination of the index against transmission to unvaccinated household contacts was 63% (95%CI 46-75%)." medrxiv.org/content/10.110…
2. UK study with Delta by genome sequencing, household transmission reduced from 38% (via unvaxxed) to 25% (vaxxed), a 35% reduction thelancet.com/journals/lanin…
3. A 2nd UK study with sequencing of Delta showed a 27% reduction of transmission for vaccinated vs unvaccinated thelancet.com/action/showPdf…
Why should every adult get a 3rd shot (booster) when eligible (6 months after 1°💉)? 1. A randomized, placebo-controlled trial, the gold standard for assessing efficacy, showed restoration of efficacy to 95.6%, in >10,000 participants across all age groups
2. Prevention of hospitalizations and deaths in a study of >728,000 people w/ 3-shots vs >728,000 matched controls (2-shots) thelancet.com/journals/lance…@TheLancet
3. We have no US National data by vaxx status but hospitalizations are starting to increase again and several states are reporting an increasing proportion of breakthroughs accounting for them
The @nytimes published "What We Know So Far About
Waning Vaccine Effectiveness" today
It is misleading and missing key reports from New York State, Veterans Affairs, Puerto Rico, Israel, Qatar, the UK, and several others nytimes.com/interactive/20…
Exemplifies bad messaging, skewed, incomplete data.
No, it's not true that "vaccines still offer strong protection against severe Covid-19" which is why the majority of at-risk US people (such as age 60+, past 6 months from 💉💉) have not gotten boosters yet
For months the media & many experts insisted the vaccines were fully protective vs severe disease while the evidence was pointing against that assertion. Still today @nytimes! No wonder the public is confused and booster uptake is low. Only 32% in the highest risk age group, 65+
Important new study on immunity (anti-spike Ab) waning and breakthrough infections after AZ & Pfizer vaccines in >5500 people 1. AZ far more pronounced and earlier waning than Pfizer & more breakthroughs
2.Anti-S correlated w/ risk of breakthroughs medrxiv.org/content/10.110…
"Our data demonstrate the importance of booster doses to maintain protection in the elderly and clinically vulnerable and suggest that these should be prioritized to those who received ChAdOx1 [AZ vaccine] as their primary course."
About timing:
"Our results show waning to levels associated with breakthrough infections before this 6 month period for those vaccinated with ChAdOx1 but not for BNT162b2."
My summary table comparing the new and highly effective anti-Covid pills, a vital step forward for prevailing over the pandemic
No head-to-head trial to know about true comparative efficacy, but key differences in mechanism and other features