2021.02.04 07:35
Viral mutations may naturally occur anywhere in the SARS-CoV-2 genome. Unlike the human DNA genome, which is slow to mutate, RNA viruses are able to readily, and quickly, mutate. A mutation may alter the viral function (eg, enhance receptor binding), or may have no discernable function.
The CDC predicts the B.1.1.7 variant (first detected in the United Kingdom) will be the major circulating variant in the United States by March 2021. [20]
Enhanced genomic surveillance in some countries have detected other variants of concern (VOCs) including B.1.351 (501Y.V2) first detected in South Africa and the B.1.1.28 (renamed P.1) (501Y.V3) which was detected in 4 travelers from Brazil during routine screening at the Tokyo airport. [20]
As of January 2021, researchers are studying how variants may or may not alter the extent of protection by available vaccines.
The immune response provoked by vaccines includes protection from the antigen by eliciting antibodies, T-cells, and interferons.
Variants that have emerged in the United Kingdom and South Africa in late 2020 have multiple mutations in their S glycoproteins (ie, the spike protein), which are key targets of currently available vaccines. [21]
In vitro studies comparing sera of neutralizing antibody titers from participants in vaccine studies describe use of sera from BNT162b2 SARS-CoV-2 vaccine showing no reduction in neutralization of pseudoviruses bearing the B.1.1.7 variant (ie, UK variant) and the B.1.351 variant (ie, South African variant). [21, 22] Similarly, the mRNA-1273 vaccine neutralizing capabilities were assessed against these variants. No significant impact on neutralization against the B.1.1.7 variant was detected in either case. A reduced, but still significant neutralization was measured against the mutations present in B.1.351. [23]
A slight decreased neutralization is not considered to be clinically significant regarding vaccine efficacy, owing to the very high efficacy of each mRNA vaccine (ie, approximately 95%). Continued variant surveillance will allow foresight for any needed changes to vaccine development or future booster doses that may be warranted.
Moderna announced its clinical strategy to proactively address the pandemic as the virus continues to evolve. The company will test an additional booster dose (ie, third dos) of its mRNA-1273 vaccine to study the ability to further increase neutralizing titers against emerging strains beyond the existing primary vaccination series. Additionally, the company is advancing mRNA-1273.351 into preclinical studies and a Phase 1 study in the United States to evaluate the immunological benefit of boosting with strain-specific spike proteins. [24]
Novavax reported preliminary efficacy results for NVX-CoV2373 vaccine from the phase 3 trial in the UK (n > 15,000). Estimated vaccine efficacy was 89.3%. The UK variant was detected in over 50% of PCR-confirmed symptomatic cases (32 UK variant, 24 nonvariant, 6 unknown). The calculated efficacy was 85.6% for the UK strain and 95.6% for the original strain. [13]
Preliminary data from the Phase 2b trial (n > 4,400) conducted in South Africa for NVX-CoV2373 reported 60% efficacy in the 94% of the study population that was HIV-negative. Among the 44 individuals testing positive for COVID-19, the South African escape variant was detected in 92.6% cases analyzed (25 out of 27 cases). [13]
Johnson & Johnson reported phase 3 trial results (EMSEMBLE; n= 43,783) for their single-dose Ad26.COV2.S viral vector vaccine in late January 2021. The trial was conducted in geographical regions and during the time when several variants emerged. At Day 28, the vaccine was 72% effective in the US, 66% in Latin America, and 57% in South Africa at preventing moderate-to-severe COVID-19 infection. Importantly, the vaccine was 85% effective in preventing severe disease and provided complete protection against COVID-related hospitalization and death in all geographic regions. Additionally, it showed consistent protection across all variants and regions studied, including South Africa where nearly all cases of COVID-19 (95%) were due to infection with a SARS-CoV-2 variant from the B.1.351 lineage. [12]
2021.02.04 07:44
2021.02.04 08:52
2021.02.06 14:12
Most substantial and of course reliable information we have lately, thanks to Dr.HJ!
It does give a bird eye view on this vaccine issue as a whole.
We learn every day, doc!
BB Lee
2021.02.06 08:17
A few years ago, someone predicted that a virus (or a germ) might lead humanity
into total extermination. He said nuclear proliferation is hardly anything to worry about
when compared to the biological tragedy.
2021.02.06 14:00
I read the same thing though can't remember exactly from where but these many people on the surface of the earth to ruin every bit of nature would get the proper punishment to be fair (?), who knows!!
Indeed, too many people, unbearably getting worse, I feel whenever I go to India every three years for almost the last three decades - similar feeling while visiting China practically every year!!!-, but at the same time, they remind me that I am not much different from them either! So this crisis might be the alarming signal I worry about.
Seriously,
BB Lee
No. | Subject | Date | Author | Last Update | Views |
---|---|---|---|---|---|
Notice | How to write your comments onto a webpage [2] | 2016.07.06 | 운영자 | 2016.11.20 | 17769 |
Notice | How to Upload Pictures in webpages | 2016.07.06 | 운영자 | 2018.10.19 | 31852 |
Notice | How to use Rich Text Editor [3] | 2016.06.28 | 운영자 | 2018.10.19 | 5494 |
Notice | How to Write a Webpage | 2016.06.28 | 운영자 | 2020.12.23 | 43427 |
8832 | 돌아오는 기러기 [1] | 2024.03.27 | 정관호*63 | 2024.03.28 | 13 |
8831 | 이강인-손흥민 ‘골 합작’ 한국, 태국 3-0 완승…월드컵 최종 예선 진출 성큼 [2] | 2024.03.26 | 황규정*65 | 2024.03.27 | 9 |
8830 | 1945년 8월 15일 오후 강릉 홍제정 안마을에서 [2] | 2024.03.19 | 정관호*63 | 2024.03.24 | 55 |
8829 | 이승만은 왜 김구를 제거 했을까? [1] | 2024.03.17 | 온기철*71 | 2024.03.18 | 34 |
8828 | My Grandson [1] | 2024.03.15 | 노영일*68 | 2024.03.18 | 77 |
8827 | 蜀相(촉상): 촉한 승상 제갈량 [1] | 2024.03.15 | 정관호*63 | 2024.03.15 | 34 |
8826 | 1945년 8월15일에는 서울에 아무일도 없었다. [1] | 2024.03.13 | 온기철*71 | 2024.03.14 | 34 |
8825 | 왕소군 고향에서 [1] | 2024.03.08 | 정관호*63 | 2024.03.20 | 37 |
8824 | 정약용; 늙어가면 친구가 점점 없어진다. [5] | 2024.03.06 | 온기철*71 | 2024.03.08 | 65 |
8823 | Trump is OK to be a candidate. | 2024.03.04 | 온기철*71 | 2024.03.17 | 46 |
8822 | AMAZING GRACE [1] | 2024.03.01 | 정관호*63 | 2024.03.08 | 50 |
8821 | 한국에의 복수국적 - 이중국적이 더 불리한 경우를 알려 드립니다 [1] | 2024.02.24 | 운영자 | 2024.02.24 | 67 |
8820 | 신진서, 농심배 16연승... 중국 기사 올킬로 한국 4연속 우승 [1] | 2024.02.23 | 황규정*65 | 2024.02.23 | 39 |
8819 | 古朝鮮:고조선 [1] | 2024.02.23 | 정관호*63 | 2024.02.26 | 41 |
8818 | 한국진공작전; Eagle Project and Napko Project [2] | 2024.02.22 | 온기철*71 | 2024.02.28 | 87 |
8817 | 일제의 김구 암살 공작과 밀정 [2] | 2024.02.19 | 온기철*71 | 2024.02.22 | 73 |
8816 | 장개석은 한국에 친중정부가 수립 되게 하려고 임정을 도왔다. [1] | 2024.02.17 | 온기철*71 | 2024.02.24 | 80 |
8815 | 봄날의 원망 [1] | 2024.02.16 | 정관호*63 | 2024.02.16 | 36 |
8814 | 내 마음은 가을 달 [1] | 2024.02.08 | 정관호*63 | 2024.02.14 | 470 |
8813 | 1945년8월15일은 과연 해방이었을까? [2] | 2024.02.06 | 온기철*71 | 2024.02.07 | 62 |
Anyhow, it sounds like we old folks might need an additional, third, boost shot down the road since the antibody would not sustain the same level after the first 6 months even for young people- wonder over 65, further 75 age group could produce even half of it to start with!- to make me feel a bit embarrassed to accept the fact - yesterday, I happened to bump to one young infectious specialist guy on the corridor and he speculated at least one of not two more booster shots through the year, hard to swallow! Embarrassing!
BB Lee