Covid-19 FAQs: Which vaccine, how to time your doses, and ways to manage delays

The photo is for representational purpose only

Amid the gloom of the coronavirus pandemic, the development of vaccines raised hopes of overcoming this disease. The immunisation drive started in 2021 but soon, jab shortages were declared in some states. Simultaneously, India was hit hard by an extremely difficult second wave of Covid-19.

The situation is improving in parts of the country and a few people are being vaccinated, however, there are still questions that need to be cleared. Dr. Sameep Sehgal, a pulmonologist at Temple University Hospital, Philadelphia, has been treating Covid-19 patients in intensive care since March 2020. Talking about his personal experience, he says the knowledge around treatments and benefits has been changing a lot in the last 12 months. "In my opinion, sometimes ‘less is more' and adding medications indiscriminately with no proven benefit can do more harm than good. We will continue to learn a lot in the next few months about this disease and we should be ready to adapt our medical practices."

In this, the concluding part of a two-part series, Sehgal talks to Mid-Day.com and answers some questions that are frequently asked about vaccine efficacy, herd immunity, and the gap between doses. Here are the excerpts:

Dr. Sameep Sehgal

What is known about the variant B.1.617? Can vaccines provide herd immunity against it?

There is a lot unknown about vaccine efficiency against this variant. Small studies have reported that the antibodies developed from vaccines are less efficacious against this variant but a lot is unknown. Each vaccine will need to be individually evaluated against this variant. Based on reports and experiences from physicians in India, the vaccines do seem to offer protection from severe infection even if you develop Covid.

Can pregnant women and lactating mothers take the vaccine?

Yes. Based on CDC and WHO recommendations, pregnant and lactating women can get the vaccines.

Separately, can a Covid positive mother breastfeed her child?

Yes.

Why aren't children being vaccinated yet?

Vaccine trials in children are ongoing and vaccines will probably be available by the end of the year for all children over 2 years age if the trial results are positive.

What are the chances of one getting infected even after taking both doses of the vaccine?

That is difficult to estimate since data against this specific variant is not yet available. However, based on what doctors are seeing in India, even if infected, vaccines seem to be protecting against severe disease.

If you have already had Covid-19, do you still need both doses of the vaccine?

Yes. While one dose may offer higher immunity if you had Covid, to obtain full benefit, both doses are recommended.

There is widespread shortage of vaccines in India. What if one misses their second dose?

While one dose may offer significant immunity, to obtain full benefit, both doses are recommended. If unable to get the second dose due to lack of availability at this time, I would suggest getting it when available. Depending on the vaccine and the circulating strains, one dose may also offer significant protection from severe disease.

How far apart should the two doses of the vaccine be? What if there is a delay?

The World Health Organization (WHO) recommends that the University of Oxford, AstraZeneca, and the Serum Institute of India vaccine be given in two doses eight to 12 weeks apart. I don't believe there is any adverse effect if there is a delay and can be taken when able to get access to the vaccine.

Other vaccines have different schedules and vary from single dose (JnJ vaccine), three weeks apart for Pfizer and four weeks apart for Moderna. Depending on availability locally the schedule should be followed.

Can one get two doses from two different manufacturers?

No. At this time all the trials are done with two doses from the same manufacturer. We will gain more information in the future from studies evaluating this question.

Also Read: Covid-19 FAQs: Which test, when to hospitalise, which drugs are recommended and when