1/ The second COVID-19 vaccine trial results have been released. 94.5% estimated efficacy! Outstanding news. These are Moderna vaccine results, independent of the Pfizer results a week ago. So there are now two independent successes!
It is the same general type of vaccine as the Pfizer vaccine. Both are RNA.
There were 90 cases of COVID-19 in the placebo group, and only 5 in the vaccinated group. That gives an ~95% efficacy calculation.
3/ There were 11 severe cases of COVID-19. Severe cases are defined as hospitalized cases that require oxygen, and frequently are ICU patients. All 11 severe cases were in the placebo group, indicated the Moderna vaccine works very well at preventing severe COVID-19.
4/ No serious safety concerns, and there is a lot of data now on safety, because over 15,000 people have received the Moderna vaccine. And another 20,000 people have received the Pfizer vaccine.
5/ As I noted when the Pfizer results were released, there was no specific reason not to expect multiple other candidate COVID-19 vaccines to do well in humans now, based on the data. And, indeed, the Moderna vaccine results look extremely good also.
6/ The biggest unknown now is probably durability of the vaccine-induced immunity. There is no licensed RNA vaccine, so there is no clear reference point for how durable immunity will be for this vaccine. However, for now, the vaccine clinical interim results are a great success!
7/ More details:
Some observers have been surprised that 90% vaccine efficacy was possible, but many vaccines are close to 100% effective, including vaccines against respiratory pathogens such as smallpox and measles.
8/ The Moderna vaccine was developed in close collaboration with the USA National Institutes of Health (NIH). Specifically, the Vaccine Research Center (VRC), which Tony Fauci has strongly supported for many years.
9/ Vaccine protection was reported based symptomatic cases, not number of infections. This endpoint was decided on because preventing systemic disease is the primary goal of COVID-19 vaccines, and...
10/ it would be extraordinarily challenging to check 40,000 people for SARS2 infections continuously for months. This clinical trial (and others) tracked self-reported symptoms, and subjects with symptoms were then tested to confirm SARS-CoV-2 infection.
11/ Specific data on success in older adults (65+) was not stated, but the phrase ‘ broadly consistent... across all subgroups” was used. It has already been published that...
12/ the Moderna vaccine does elicit immune responses in older adults (age 71+) similar to younger adults. Both neutralizing antibodies and CD4 T cells. So, very good news again for protecting older adults. bit.ly/3pt1unv
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2/ We assessed immune memory of all three branches of adaptive immunity (CD4+ T cell, CD8+ T cell, and humoral immunity—both antibodies and memory B cells) in a mixed cross-sectional and longitudinal study of 185 recovered COVID-19 cases, including 41 cases > 6 months post-COVID.
3/ Sources of protective immunity against SARS-CoV-2 may be multifaceted. Therefore, understanding immune memory in a coordinated manner is needed to see the potential complexities and gain insights into the likelihood of durability of protective immunity.
1/ This is a truly excellent and important outcome. Greater than 90% efficacy at preventing disease, with 94 COVID-19 cases to evaluate, is an excellent outcome! It would be good to see more of the data, but those are very convincing numbers.
2/ It is also encouraging that the 90% efficacy is for all cases, not just a subset of cases. Finally, I find it very encouraging for the other COVID-19 candidate vaccines also!
3/ Multiple candidate vaccines had similar immunogenicity profiles in humans, and multiple candidate vaccines had efficacy in pre-clinical models, so there is not specific reason not to expect multiple other candidate vaccines to do well in humans nows.
2/ Given the amount of discussion in scientific, public, and political spheres, it is useful to undertake a thought experiment examining crossreactive T cell effects on COVID-19 disease severity and herd immunity, should crossreactive memory T cells confer some form of protection
3/ We consider immunological and epidemiological aspects and implications of pre-existing crossreactive immune memory to SARS-CoV-2, largely originating from previous exposure to circulating common cold coronaviruses.
2) There is no direct evidence that pre-existing T cell immunity affects COVID-19 infections. LJI researchers and other have proven that such T cells exist, but neither we nor anyone else have shown that the pre-existing T cells make COVID-19 better, worse, or no difference.
3) To say it another way, There is no direct evidence that crossreactive memory T cells to common cold viruses affects COVID-19.
Crotty lab member of the week is Carolyn Rydyznski Moderbacher, PhD! 1. Carolyn is the lead author of our new COVID-19 immunology paper studying T cell and antibody responses in acute COVID-19 cases. cell.com/cell/fulltext/… @ljiresearch
2. Carolyn wasn’t planning on working on COVID-19, but she had developed excellent multi parameter flow cytometry panels for other human T cell studies, and AIM assays, and I needed her to take the lead on COVID-19 T cell work,
3. so she dropped her other project and has worked full time on COVID-19 for the past 6 months, trying to understand immunity to COVID-19. Culminating in the new paper.
2/ We aimed to better understand hospitalized COVID-19 cases by examining virus-specific immune responses all in the same people. SARS2-specific Helper T cells, killer T cells, and neutralizing antibodies.
3/ (I.e., measure the adaptive immune response in acute COVID-19 cases with virus-specific tools.)