Thread by @MonicaGandhi9

Pfizer CEO said boosters may be needed. Unlikely
1) T cell immunity from vax (and Abs) work against variants; 2) T cells last long time- 34 y & counting after measles vax; 3) 1st SARS recovered have T cells 17 yr later; 4) Covid Vax generate memory B cells (lymph node biopsy)

So, to back up each claim (I have longer thread on this)
1) T cell immunity from vax works against variants: I hope you have been persuaded
2) T cells last 34 years and counting after measles vaccine:
ncbi.nlm.nih.gov/pmc/articles/P…

3) First SARS pandemic was coronavirus like this one (called SARS-CoV) and it also called severe disease. Lasted 9 months late 2002-2003. Survivors of similar virus SARS have strong T cell immunity 17 years later and counting
nature.com/articles/s4158…

Here is another paper on that LONG-LASTING T cell immunity from SARS-CoV (first SARS) and also another coronavirus that caused severe disease in 2011 called MERS
sciencedirect.com/science/articl…

Remember long-lived memory B & T cells stored in germinal centers (like lymph nodes) in our body & generate responses to fight the virus if see again. 32 people who received 2 doses of mRNA vax had lymph nodes biopsied; found B cells against covid in all: researchsquare.com/article/rs-310…

And we all remember that memory B cells from survivors of 1918 flu pandemic were still there 90 years later and could fight the 1918 flu virus if they saw it again by producing antibodies! So, wouldn't worry too much Pfizer CEO announcement about boosters
nature.com/articles/natur…

Oh & why do we need annual flu vaccines? Influenza virus is an RNA virus with much higher mutation rate than coronavirus which actually has a lot of fidelity in replication; doesn't mutate that fast. Also current flu vax not great; need global flu vax
journals.plos.org/plospathogens/…

When I see this article that some are being dissuaded from taking the vaccine because the Pfizer CEO said he will have booster shots ready for us, this is upsetting given the above reasons boosters prob not needed. Could public health please message above? washingtonpost.com/health/2021/04…

In fact, when I see reason is that people are worried this will never end, I would ask public health to increase confidence in vaccines by 1) taking about likely durability of response; 2) come up with clear metrics of when masks/distancing will end to increase vax uptake

I see situation in India is making people question the effect of immunity on ending pandemics. I believe immunity to coronaviruses that are severe likely long-lived for above 5 reasons (T cells, memory B cells & coronavirus doesn't mutate as fast as influenza) but to address:

1) Immunity to pathogens does end pandemics: reason HIV, TB, malaria aren't done is because no/less effective vaccines (HIV actually infects T cells). Without vax, with a very mutable virus (influenza), 1918 flu pandemic sadly ended after 50 million deaths
npr.org/2020/04/02/826…

2) Influenza & coronavirus both RNA viruses (don't intercalate into human chromosome like retroviruses, example is HIV). Coronavirus "polymerase" (what makes it replicate) much less error-prone than influenza but lots of transmission allows mutations to occur (variants)

3) Mistake I, others made in India (I made huge error, so sorry) is assuming seroprevalence studies from slums in Mumbai showing ~60% exposure representative of immunity of 1.4 billion people. Lancet paper: 55·1% to 61·4% slums; 12·0% to 18·9% in non-slums
thelancet.com/journals/langl…

If you recall, same thing happened in July 2020 when this seroprevalence study came out from Queens. Seroprevalence from hard-hit community in major urban center does not represent immunity in a large city with more middle-class/wealthy able to shelter
nytimes.com/2020/07/09/nyr…

What is happening in India is tragic; we must do everything in our power to help surge vaccines and vaccine supply to this large country. But India is not emblematic that immunity to a pathogen doesn't end pandemics; high immunity in wealthy countries from rapid vax roll-out real