Highlights
- Current antibodies may work against some but not all variants: Expert
- The virus will likely continue to evolve over time and space: Expert
- Coronavirus uses a protein called spike to attach to and invade cells
Washington: Researchers have identified an antibody that is highly protective at low doses against a wide range of variants of the SARS-CoV-2 virus which causes COVID-19. The findings, posted as a pre-proof in the journal Immunity, could help develop new antibody-based therapies that are less likely to lose their potency as the virus mutates.
Also Read: India Does Not Have Sufficient Data To Decide On COVID-19 Booster Dose: Experts
The new antibody attaches to a part of the virus that differs little across the variants, meaning that it is unlikely for resistance to arise at this spot, the researchers said.
Current antibodies may work against some but not all variants. The virus will likely continue to evolve over time and space. Having broadly neutralising, effective antibodies that work individually and can be paired to make new combinations will likely prevent resistance, said study senior author Michael S Diamond, a professor at Washington University School of Medicine in St Louis, US.
The SARS-CoV-2 virus uses a protein called spike to attach to and invade cells in the body’s respiratory tract. Antibodies that prevent the spike protein from attaching to cells neutralise the virus and prevent disease.
Many variants have acquired mutations in their spike genes that allow them to evade some antibodies generated against the original strain, undermining the effectiveness of antibody-based therapeutics.
To find neutralising antibodies that work against a wide range of variants, the researchers immunised mice with a key part of the spike protein known as the receptor-binding domain (RBD). They then extracted antibody-producing cells and obtained 43 antibodies from them that recognise RBD.
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The team screened the 43 antibodies by measuring how well they prevented the original variant of SARS-CoV-2, that emerged in 2019, from infecting cells in a dish. Nine of the most potent neutralising antibodies were then tested in mice to see whether they could protect animals infected with the original virus from disease.
Multiple antibodies passed both tests, with varying degrees of potency, according to the researchers. They selected the two antibodies that were most effective at protecting mice from disease and tested them against a panel of viral variants.
The panel comprised viruses with spike proteins representing all four variants of concern — Alpha, Beta, Gamma and Delta — two variants of interest (Kappa and Iota), and several unnamed variants that are being monitored as potential threats.
The researchers found that one antibody, SARS2-38, easily neutralised all the variants, a humanised version of SARS2-38 protected mice against disease caused by two variants: Kappa and a virus containing the spike protein from the Beta variant, they said. The Beta variant is notoriously resistant to antibodies, so its inability to resist SARS2-38 is particularly remarkable, the researchers noted.
Further experiments pinpointed the precise spot on the spike protein recognised by the antibody, and identified two mutations at that spot that could, in principle, prevent the antibody from working. However, these mutations are rare in the real world, the researchers said. They searched a database of nearly 800,000 SARS-CoV-2 sequences and found escape mutations in only 0.04 per cent of them.
This antibody is both highly neutralising (meaning it works very well at low concentrations) and broadly neutralising (meaning it works against all variants). That’s an unusual and very desirable combination for an antibody. Also, it binds to a unique spot on the spike protein that isn’t targeted by other antibodies under development. That’s great for combination therapy, the scientist explained.
The researchers said this antibody can be combined with another one that binds somewhere else to create a combination therapy that would be very difficult for the virus to resist.
Also Read: US Food And Drug Administration Gives Full Approval To Pfizer-BioNTech COVID-19 Vaccine
(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)
NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene.
World
21,25,27,888Cases
17,63,66,490Active
3,17,20,112Recovered
44,41,286Deaths
Coronavirus has spread to 195 countries. The total confirmed cases worldwide are 21,25,27,888 and 44,41,286 have died; 17,63,66,490 are active cases and 3,17,20,112 have recovered as on August 24, 2021 at 3:51 am.
India
3,24,74,773 25,467Cases
3,19,55114,373Active
3,17,20,112 39,486Recovered
4,35,110 354Deaths
In India, there are 3,24,74,773 confirmed cases including 4,35,110 deaths. The number of active cases is 3,19,551 and 3,17,20,112 have recovered as on August 24, 2021 at 2:30 am.
State Details
State | Cases | Active | Recovered | Deaths |
---|---|---|---|---|
Maharashtra |
64,28,294 3,643 |
53,433 3,257 |
62,38,794 6,795 |
1,36,067 105 |
Kerala |
38,27,688 13,383 |
1,55,096 8,649 |
36,53,008 21,942 |
19,584 90 |
Karnataka |
29,39,767 1,151 |
20,281 301 |
28,82,331 1,442 |
37,155 10 |
Tamil Nadu |
26,02,489 1,604 |
18,887 284 |
25,48,868 1,863 |
34,734 25 |
Andhra Pradesh |
20,03,342 1,002 |
14,159 518 |
19,75,448 1,508 |
13,735 12 |
Uttar Pradesh |
17,09,126 7 |
362 11 |
16,85,972 18 |
22,792 |
West Bengal |
15,43,496 510 |
9,336 125 |
15,15,789 628 |
18,371 7 |
Delhi |
14,37,334 17 |
374 24 |
14,11,881 41 |
25,079 |
Chhattisgarh |
10,04,183 39 |
709 154 |
9,89,920 192 |
13,554 1 |
Odisha |
10,01,698 761 |
7,938 339 |
9,86,334 1,032 |
7,426 68 |
Rajasthan |
9,54,030 7 |
159 7 |
9,44,917 |
8,954 |
Gujarat |
8,25,316 14 |
171 11 |
8,15,066 25 |
10,079 |
Madhya Pradesh |
7,92,104 3 |
84 2 |
7,81,504 5 |
10,516 |
Haryana |
7,70,362 15 |
668 8 |
7,60,026 22 |
9,668 1 |
Bihar |
7,25,596 8 |
112 29 |
7,15,834 36 |
9,650 1 |
Telangana |
6,55,343 354 |
6,308 76 |
6,45,174 427 |
3,861 3 |
Punjab |
6,00,292 26 |
421 67 |
5,83,518 92 |
16,353 1 |
Assam |
5,85,134 700 |
7,995 16 |
5,71,552 705 |
5,587 11 |
Jharkhand |
3,47,748 18 |
165 12 |
3,42,451 30 |
5,132 |
Uttarakhand |
3,42,771 22 |
313 4 |
3,35,081 26 |
7,377 |
Jammu And Kashmir |
3,24,295 93 |
1,054 111 |
3,18,838 203 |
4,403 1 |
Himachal Pradesh |
2,11,979 233 |
2,030 44 |
2,06,375 272 |
3,574 5 |
Goa |
1,73,221 57 |
875 24 |
1,69,160 80 |
3,186 1 |
Puducherry |
1,22,934 42 |
796 51 |
1,20,330 93 |
1,808 |
Manipur |
1,11,212 270 |
3,706 288 |
1,05,751 554 |
1,755 4 |
Tripura |
82,260 165 |
1,135 40 |
80,335 122 |
790 3 |
Meghalaya |
74,070 305 |
2,930 132 |
69,859 434 |
1,281 3 |
Chandigarh |
65,068 2 |
36 5 |
64,220 7 |
812 |
Mizoram |
53,317 845 |
6,328 346 |
46,789 499 |
200 |
Arunachal Pradesh |
52,308 94 |
1,162 98 |
50,887 192 |
259 |
Nagaland |
29,622 33 |
916 59 |
28,096 92 |
610 |
Sikkim |
29,340 26 |
1,507 76 |
27,466 100 |
367 2 |
Ladakh |
20,499 8 |
63 2 |
20,229 6 |
207 |
Dadra And Nagar Haveli |
10,659 |
4 0 |
10,651 |
4 |
Lakshadweep |
10,317 8 |
28 5 |
10,238 3 |
51 |
Andaman And Nicobar Islands |
7,559 2 |
10 2 |
7,420 |
129 |