Connect with us

Coronavirus Outbreak

Pfizer, AstraZeneca Vaccine Antibody Levels May Decline After 2-3 Months: Lancet Study

The UCL Virus Watch study found that antibody levels are substantially higher following two doses of the Pfizer vaccine than after two shots of the AstraZeneca preventive, known as Covishield in India

Even when measurable antibody levels are low, there is likely to be continuing immune memory that could offer long-term protection against COVID-19: Study
Highlights
  • Antibody levels were higher in vaccinated people than those with COVID
  • The study was conducted by researchers from University College London (UCL)
  • The findings based on data from over 600 people aged 18 and above

London: Total antibody levels start to wane six weeks after complete immunisation with Pfizer and AstraZeneca vaccines, and can reduce by more than 50 per cent over 10 weeks, according to study published in The Lancet journal. The researchers from University College London (UCL) in the UK noted that if the antibody levels carry on dropping at this rate, there are concerns that the protective effects of the vaccines may also begin to wear off, particularly against new variants. However, they said, how soon that might happen cannot be predicted yet.

The UCL Virus Watch study also found that antibody levels are substantially higher following two doses of the Pfizer vaccine than after two shots of the AstraZeneca preventive, known as Covishield in India. Antibody levels were also much higher in vaccinated people than those with prior SARS-CoV-2 infection, they said.

Also Read: Covid Vaccines For Children: Experts Speak On The Options Available For India

The levels of antibody following both doses of either the AstraZeneca or Pfizer vaccine were initially very high, which is likely to be an important part of why they are so protective against severe COVID-19, said Madhumita Shrotri from UCL Institute of Health Informatics. However, we found these levels dropped substantially over the course of two to three months, Dr Shrotri said in a statement.

The findings based on data from over 600 people aged 18 and above were consistent across all groups of people regardless of age, chronic illnesses or sex, according to the researchers.

The authors highlight that although the clinical implications of waning antibody levels are not yet clear, some decline was expected and current research shows that vaccines remain effective against severe disease.

For Pfizer, antibody levels reduced from a median of 7506 Units per millilitre (U/mL) at 2141 days, to 3320 U/mL at 70 or more days. For AstraZeneca vaccine, antibody levels reduced from a median of 1201 U/mL at 020 days to 190 U/mL at 70 or more days, over five-fold reduction.

When we are thinking about who should be prioritised for booster doses our data suggests that those vaccinated earliest, particularly with the AstraZeneca vaccine, are likely to now have the lowest antibody levels, said Professor Rob Aldridge from UCL Institute of Health Informatics.

Also Read: Made In India Sputnik V To Be Available During September- October: Dr Reddy’s

The findings support recommendations that adults who are clinically vulnerable, those aged 70 years or over, and all residents of care homes for older adults should be prioritised for booster doses, the researchers said. In addition, those who were vaccinated with the AstraZeneca vaccine are likely to have much lower antibody levels than those vaccinated with the Pfizer vaccine, they noted.

This may also need to be considered when deciding who should be prioritised when boosters are rolled out, Prof. Aldridge said in the statement. The team acknowledged certain limitations in the data, including a small sample size for some groups.

The researchers noted that that each individual only contributed one sample, so they cannot yet confirm how quickly antibody levels drop for each individual, or whether these would continue to drop or reach a stable level over the next few months. They also noted that different people will have different levels of immunity depending on the virus neutralising ability of their antibodies as well as their T-cell responses.

Even when measurable antibody levels are low, there is likely to be continuing immune memory that could offer long-term protection, the authors of the study noted.

They said further research will be important to establish if there is an antibody level threshold needed for protection against severe disease.

(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 (WaterSanitation 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 pollutionwaste managementplastic banmanual scavenging and sanitation workers and menstrual hygiene

World

24,50,12,529Cases
20,64,25,824Active
3,36,14,434Recovered
49,72,271Deaths
Coronavirus has spread to 195 countries. The total confirmed cases worldwide are 24,50,12,529 and 49,72,271 have died; 20,64,25,824 are active cases and 3,36,14,434 have recovered as on October 28, 2021 at 4:00 am.

India

3,42,31,809 16,156Cases
1,60,9891,672Active
3,36,14,434 17,095Recovered
4,56,386 733Deaths
In India, there are 3,42,31,809 confirmed cases including 4,56,386 deaths. The number of active cases is 1,60,989 and 3,36,14,434 have recovered as on October 28, 2021 at 2:30 am.

State Details

State Cases Active Recovered Deaths
Maharashtra

66,06,536 1,485

23,096 3,500

64,43,342 4,947

1,40,098 38

Kerala

49,38,603 9,445

77,158 2,100

48,31,468 6,723

29,977 622

Karnataka

29,86,835 282

8,459 80

29,40,339 349

38,037 13

Tamil Nadu

26,98,493 1,075

12,288 252

26,50,145 1,315

36,060 12

Andhra Pradesh

20,64,854 567

4,777 122

20,45,713 437

14,364 8

Uttar Pradesh

17,10,114 13

100 6

16,87,115 7

22,899

West Bengal

15,89,042 976

7,973 124

15,61,973 837

19,096 15

Delhi

14,39,709 38

348 25

14,14,270 13

25,091

Odisha

10,39,818 549

4,392 213

10,27,108 334

8,318 2

Chhattisgarh

10,05,926 28

263 14

9,92,088 12

13,575 2

Rajasthan

9,54,411 4

20 0

9,45,437 4

8,954

Gujarat

8,26,481 17

173 2

8,16,220 15

10,088

Madhya Pradesh

7,92,804 20

108 9

7,82,172 10

10,524 1

Haryana

7,71,204 15

133 5

7,61,022 10

10,049

Bihar

7,26,073 5

41 1

7,16,371 4

9,661

Telangana

6,70,829 186

4,164 63

6,62,714 122

3,951 1

Assam

6,09,506 244

3,838 153

5,99,681 391

5,987 6

Punjab

6,02,289 38

246 20

5,85,487 16

16,556 2

Jharkhand

3,48,705 28

160 30

3,43,408 56

5,137 2

Uttarakhand

3,43,861 17

150 6

3,36,312 23

7,399

Jammu And Kashmir

3,31,865 70

838 16

3,26,596 86

4,431

Himachal Pradesh

2,23,406 261

1,972 211

2,17,693 48

3,741 2

Goa

1,77,969 23

454 29

1,74,152 51

3,363 1

Puducherry

1,27,846 40

443 10

1,25,546 50

1,857

Manipur

1,23,473 70

844 29

1,20,712 97

1,917 2

Mizoram

1,19,496 547

7,320 446

1,11,752 991

424 2

Tripura

84,438 15

123 1

83,499 14

816

Meghalaya

83,466 51

507 22

81,511 71

1,448 2

Chandigarh

65,331 5

29 2

64,482 3

820

Arunachal Pradesh

55,120 6

115 22

54,725 28

280

Sikkim

31,925 13

177 1

31,353 12

395

Nagaland

31,759 12

222 3

30,856 15

681

Ladakh

20,925 8

47 6

20,670 2

208

Dadra And Nagar Haveli

10,682 1

6 0

10,672 1

4

Lakshadweep

10,365

0 0

10,314

51

Andaman And Nicobar Islands

7,650 2

5 1

7,516 1

129

Coronavirus Outbreak: Full CoverageTesting CentresFAQs

Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Highlights From The 12-Hour Telethon

Leaving No One Behind

Mental Health

Environment

Join Us