Booster Effect Even At Six Months, Don’t Worry: Experts On Covishield Dose Gap

Booster Effect Even At Six Months, Don’t Worry: Experts On Covishield Dose Gap

According to expert, vaccine doses will be safe no matter when they are taken but will not provide any great boosting if given within less than a month or so of the previous dose
Coronavirus Outbreak, Coronavirus Vaccine, News
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Booster Effect Even At Six Months, Don't Worry: Experts On Covishield Dose GapThe government last week extended the gap between two doses of the Covishield COVID-19 vaccine to 12-16 weeks
Highlights
  • The increased window will enable more people to be vaccinated: Expert
  • Vaccine supply is likely to be limited, at least in the short term: Expert
  • India has approved 3 COVID vaccines: Covishield, Covaxin and Sputnik V

New Delhi: Four to six weeks, six to eight or eight to 12? The increasing gap between two Covishield doses in India while the UK reduces its window has laypersons confused, but several experts say there is little reason to worry and second jabs anytime before six months can still be effective boosters. The government last week extended the gap between two doses of the Covishield COVID-19 vaccine to 12-16 weeks, up from the previous maximum of eight weeks, on the recommendation of the National Technical Advisory Group on Immunisation (NTAGI). A day later, UK cut the gap from 12 weeks to eight weeks in view of the spread of the B.1.617 variant that originated in India.

Also Read: Vaccinating As Many People As Possible Should Be The Top Priority, Says Ebola Virus’s Co-Discoverer On India’s COVID-19 Crisis

Responding to concerns that India increased the gap primarily because vaccines were in short supply and many states had complained of acute shortage in supplies, immunologist Satyajit Rath said vaccine dosing is “quite flexible and forgiving”. Once four weeks have passed, the next dose can be taken whenever practicable, until six months. According to the scientist, vaccine doses will be safe no matter when they are taken but will not provide any great “boosting” if given within less than a month or so of the previous dose.

So vaccine doses can be taken any time after at least four weeks have passed from either the first dose or after an actual episode of COVID-19. Secondly, vaccine doses will give perfectly good boosting if given any time up to as much as six months or so after a previous dose. So a second dose, or the first dose after a COVID-19 episode, does not have to be taken after four weeks, Mr. Rath, from New Delhi’s National Institute of Immunology (NII), told PTI.

The NTAGI, Mr. Rath added, is making these new recommendations based on evidence, and trying to provide support for practical steps. Referring to the UK reducing its Covishield doses gap just as India increased its, immunologist Vineeta Bal said these decisions are taken based on ground realities and “there is no yes or no answer” to whether they will have any consequence on tackling the variant better.

Also Read: Dr Reddy’s Labs, Apollo Hospitals Launch Pilot Programme For Administering Russian COVID Vaccine Sputnik V

In one country, the increased window will enable more people to be vaccinated, in the other, a decreased gap will accelerate the pace of inoculation.

If there are enough doses available, the second shot should be given at the optimal time as it will provide the best possible immunity in the present circumstances, Ms. Bal, guest faculty at Pune’s Indian Institute of Science Education and Research, told PTI.

A vaccine triggered immune response, she admitted, will start declining with time.

However, at the end of 12-16 weeks it is unlikely to come to complete baseline level. “Hence a booster effect can still be obtained after a gap of 12-16 weeks,” Ms. Bal said.

There are also data from various clinical trials for Covishield which are suggestive that a booster after 12-16 weeks will be fine, she added.

According to Mr. Rath, there is emerging evidence, mostly from the UK for Covishield, that very good protection is seen with a dose gap of 12 odd weeks.

So I think that the committee is trying to provide evidence-based support for delaying the permissible interval between doses as much as possible to accommodate the realities of vaccine supply shortage, he added.

Ms. Bal added it is not a serious cause of concern as long as there is assurance that everyone will get the first and second dose in the near future. According to a peer-reviewed study published in The Lancet in February, the coronavirus vaccine developed by AstraZeneca and Oxford University is more effective when its second dose is given around three months after the first, instead of six weeks later.

Vaccine supply is likely to be limited, at least in the short term, and so policy-makers must decide how best to deliver doses to achieve the greatest public health benefit. Where there is a limited supply, policies of initially vaccinating more people with a single dose may provide greater immediate population protection than vaccinating half the number of people with 2 doses, Prof Andrew Pollard of the University of Oxford said in the study.

In India, the gap between two Covishield doses was four to six weeks, then increased to six to eight, and is now 12-16.

Based on the available real-life evidences, particularly from the UK, the COVID-19 Working Group agreed for increasing the dosing interval to 12-16 weeks between two doses of Covishield vaccine. No change in interval of Covaxin vaccine doses was recommended, the Health Ministry said last week.

The NTAGI has also stated that those having laboratory test proven SARS-CoV-2 illness should defer COVID-19 vaccination for six months after recovery. According to the Health Ministry’s current protocol, the vaccine is to be taken four to eight weeks after recovery from COVID-19.

Also Read: Bleeding, Clotting Cases After Covishield Jab “Minuscule”: Centre’s Panel

Mr. Rath said the basis for this step seems to be based on the fact that there are good antibody levels in most people who have had COVID-19 and that they last for at least six months. So they are likely to be well protected for that period, and therefore there is no pressing need to vaccinate them before that, the scientist said.

This reduces the burden on the stuttering vaccine supply and distribution system. I am not in disagreement with the recommendations based on such a rationale, he added.

However, the immunologist hoped that the rationale will be clearly explained. If there is no explanation, it will add to confusion. Most viral infections, Bal noted, generate enough immunity to provide protection for a few months post-recovery. Based on that knowledge, this recommendation is not unreasonable.

RT-PCR positive patients post-recovery do not remain as vulnerable as those who are neither vaccinated nor infected. They have enough immunity in them, generally. Just because of this recommendation, the situation is not likely to worsen in India. Other things like unavailability of vaccine for a large section of people is more of a problem, she explained.

On NTAGI suggesting no changed in the protocol for Covaxin, the other vaccine being administered in India, Rath said this is likely because the recommendations are based on UK-based evidence with Covishield. There is no such evidence for Covaxin.

I am glad since this suggests that the committee, as I keep saying, is trying very hard to stay carefully on evidence while trying to help with the current unhappy realities, he said.

Also Read: COVID-19 Vaccine Passports: Why These Are Good For Society

(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

19,89,21,889Cases
6,44,02,340Active
13,02,83,678Recovered
42,35,871Deaths
Coronavirus has spread to 194 countries. The total confirmed cases worldwide are 19,89,21,889 and 42,35,871 have died; 6,44,02,340 are active cases and 13,02,83,678 have recovered as on August 3, 2021 at 3:55 am.

India

3,17,26,507 30,549Cases
4,04,9588,760Active
3,08,96,354 38,887Recovered
4,25,195 422Deaths
In India, there are 3,17,26,507 confirmed cases including 4,25,195 deaths. The number of active cases is 4,04,958 and 3,08,96,354 have recovered as on August 3, 2021 at 2:30 am.

State Details

State Cases Active Recovered Deaths
Maharashtra

63,15,063 4,869

78,700 3,650

61,03,325 8,429

1,33,038 90

Kerala

34,25,473 13,984

1,65,834 2,057

32,42,684 15,923

16,955 118

Karnataka

29,08,284 1,285

24,045 123

28,47,627 1,383

36,612 25

Tamil Nadu

25,63,544 1,957

20,385 139

25,09,029 2,068

34,130 28

Andhra Pradesh

19,70,008 1,546

20,582 437

19,36,016 1,968

13,410 15

Uttar Pradesh

17,08,500 24

646 18

16,85,091 42

22,763

West Bengal

15,29,295 575

10,803 171

15,00,331 734

18,161 12

Delhi

14,36,401 51

538 44

14,10,809 95

25,054

Chhattisgarh

10,02,458 236

1,918 1

9,87,012 234

13,528 3

Odisha

9,79,737 1,032

13,318 820

9,60,386 1,785

6,033 67

Rajasthan

9,53,704 16

241 9

9,44,509 25

8,954

Gujarat

8,24,922 22

251 3

8,14,595 25

10,076

Madhya Pradesh

7,91,862 17

132 7

7,81,217 10

10,513

Haryana

7,69,956 14

703 12

7,59,614 25

9,639 1

Bihar

7,24,917 37

401 34

7,14,872 71

9,644

Telangana

6,45,997 591

8,819 54

6,33,371 643

3,807 2

Punjab

5,99,162 32

473 31

5,82,395 63

16,294

Assam

5,68,257 1,275

12,429 213

5,50,534 1,469

5,294 19

Jharkhand

3,47,223 23

239 15

3,41,855 38

5,129

Uttarakhand

3,42,198 37

574 35

3,34,261 71

7,363 1

Jammu And Kashmir

3,21,725 118

1,254 43

3,16,090 73

4,381 2

Himachal Pradesh

2,06,369 208

1,304 75

2,01,543 132

3,522 1

Goa

1,71,295 90

1,027 16

1,67,118 72

3,150 2

Puducherry

1,21,059 54

944 38

1,18,320 92

1,795

Manipur

99,872 541

9,814 591

88,480 1,120

1,578 12

Tripura

79,026 304

3,104 12

75,167 292

755

Meghalaya

65,939 350

5,843 200

58,987 537

1,109 13

Chandigarh

61,960 6

33 3

61,116 3

811

Arunachal Pradesh

48,565 305

3,508 167

44,823 469

234 3

Mizoram

40,111 748

12,316 127

27,642 618

153 3

Nagaland

28,004 59

1,300 44

26,130 99

574 4

Sikkim

26,880 126

3,323 131

23,211 256

346 1

Ladakh

20,345 5

57 0

20,081 5

207

Dadra And Nagar Haveli

10,650

15 9

10,631 9

4

Lakshadweep

10,207 12

79 4

10,078 8

50

Andaman And Nicobar Islands

7,539

6 1

7,404 1

129

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