Connect with us

Coronavirus Outbreak

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

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

24,06,78,961Cases
20,23,40,977Active
3,34,39,331Recovered
48,98,653Deaths
Coronavirus has spread to 195 countries. The total confirmed cases worldwide are 24,06,78,961 and 48,98,653 have died; 20,23,40,977 are active cases and 3,34,39,331 have recovered as on October 18, 2021 at 4:17 am.

India

3,40,81,315 13,596Cases
1,89,6946,152Active
3,34,39,331 19,582Recovered
4,52,290 166Deaths
In India, there are 3,40,81,315 confirmed cases including 4,52,290 deaths. The number of active cases is 1,89,694 and 3,34,39,331 have recovered as on October 18, 2021 at 2:30 am.

State Details

State Cases Active Recovered Deaths
Maharashtra

65,91,697 1,715

32,230 994

64,19,678 2,680

1,39,789 29

Kerala

48,54,321 7,555

88,186 3,292

47,39,270 10,773

26,865 74

Karnataka

29,83,459 326

9,479 58

29,36,039 380

37,941 4

Tamil Nadu

26,87,092 1,218

14,814 208

26,36,379 1,411

35,899 15

Andhra Pradesh

20,60,472 432

6,034 159

20,40,131 586

14,307 5

Uttar Pradesh

17,10,028 9

119 10

16,87,011 19

22,898

West Bengal

15,80,530 624

7,421 24

15,54,132 634

18,977 14

Delhi

14,39,390 32

320 6

14,13,981 38

25,089

Odisha

10,35,077 443

4,542 68

10,22,250 508

8,285 3

Chhattisgarh

10,05,654 16

183 2

9,91,901 14

13,570

Rajasthan

9,54,390 2

42 2

9,45,394 4

8,954

Gujarat

8,26,290 10

207 6

8,15,997 16

10,086

Madhya Pradesh

7,92,684 5

84 12

7,82,077 17

10,523

Haryana

7,71,076 15

123 9

7,60,904 6

10,049

Bihar

7,26,026 5

48 4

7,16,317 1

9,661

Telangana

6,68,955 122

3,924 55

6,61,093 176

3,938 1

Assam

6,06,468 205

3,436 46

5,97,082 245

5,950 6

Punjab

6,02,035 27

227 8

5,85,264 16

16,544 3

Jharkhand

3,48,430 7

122 1

3,43,173 8

5,135

Uttarakhand

3,43,756 9

178 1

3,36,181 8

7,397

Jammu And Kashmir

3,31,062 95

843 12

3,25,793 107

4,426

Himachal Pradesh

2,21,437 131

1,303 5

2,16,414 125

3,720 1

Goa

1,77,522 60

604 6

1,73,572 62

3,346 4

Puducherry

1,27,396 52

585 13

1,24,961 64

1,850 1

Manipur

1,22,737 104

1,422 0

1,19,418 102

1,897 2

Mizoram

1,12,848 249

11,633 1,143

1,00,829 1,389

386 3

Tripura

84,321 16

104 4

83,401 12

816

Meghalaya

82,953 55

845 32

80,673 86

1,435 1

Chandigarh

65,302 3

25 3

64,457 6

820

Arunachal Pradesh

54,987 7

140 30

54,567 37

280

Sikkim

31,749 4

174 8

31,184 12

391

Nagaland

31,611 40

248 12

30,689 28

674

Ladakh

20,878 2

36 10

20,634 12

208

Dadra And Nagar Haveli

10,676 1

4 1

10,668

4

Lakshadweep

10,365

0 0

10,314

51

Andaman And Nicobar Islands

7,641

9 0

7,503

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