FAQ: What Happens if I Miss My Second Dose of COVID Vaccine?

Thanks to vaccine shortage across the country, many Indians are missing their date for the booster dose.

A file phot of a private security guard standing outside an empty COVID-19 vaccination in Mumbai. Image used for representation.

(PTI Photo/Kunal Patil)

As lakhs of adults between 18 and 44 years are trying to win the ‘fastest-finger-first’ challenge on CoWIN, hoping to get their first dose of coronavirus vaccine, countless Indians are missing their timeline for a second jab.

Although shortage of vaccines across the country is the primary reason, lockdowns, lack of access, and coronavirus itself have made Indians miss their timeline for the booster dose.

What happens when you miss your second dose? How long can you wait before you take your second dose of Covaxin or Covishield? Here’s what you need to know.

I have got the first dose of COVID-19 vaccine. But I am not able to find slots for the second dose. Can I miss my second shot?

No, if you miss your second shot, you will be less protected — and if exposed to COVID-19, you may not only get infected but also have chances of getting infected severely.

Dr Jacob John, virologist and former head of the Indian Council for Medical Research, explains that in most cases, the first dose only does ‘priming’.

To break it down, a live virus vaccine like that of measles multiplies in your body to give you immunity. But a non-replicating vaccine like the coronavirus vaccine, only readies your immune system.

“The second dose boosts the immune system that is already primed. This concept is called prime-boost immunisation. While you might get some protection from first dose, full-potential efficiency is possible only if boosted.”

Dr Jacob John

The partial immunity from the first dose, Dr Jacob says, will diminish over time — if not boosted. While a slight delay of few weeks will not impact the efficacy, taking the second shot is most important, he adds.

What is the stipulated time period to take the second dose of vaccine?

According to the Ministry of Health and Family Welfare (MoHFW), the second dose of:

• Covishield is to be taken between 12-16 weeks
• Covaxin is to be taken after 28 days since first dose

I got a slot for Covishield vaccine 10 weeks after my first shot. Is that okay? Can I take it?

India on Thursday, 13 May, increased the gap between the two doses of Serum Institute's COVID-19 vaccine, Covishield, to 12-16 weeks, based on the recommendation by a government panel from the National Technical Advisory Group on Immunisation (NTAGI).

Data from the UK for AstraZeneca aka Covishield shows that it can be safely delayed up to three months. Dr Gagandeep Kang, in an interview with FIT, suggested that India should consider delaying the second shot for Covishield vaccine. This will not only help deal with vaccine shortage but also provide better efficacy in the longer run.

“The UK decided early on that for both Pfizer and Covishield vaccines, they will delay the second dose by three months. Now we have real-world-use data of what single dose of AstraZeneca vaccine can achieve. The single dose provides very good protection against hospitalisation and death. So, it can offer protection for at least three months. If there is an issue with the supply, the AstraZeneca vaccine, you can safely delay up to three months.”

Dr Gagandeep Kang

“In the longer run too, we might find that the three-month gap is better than the one-month gap. Immunologically, in the long run, extending the gap between two doses will give you longer protection and we don’t want to be running around to get booster dose,” she added.

What about Covaxin? Can I delay it by 12 weeks as well?

For Covaxin, the variation between doses was not tested in human trials.

“The makers had uniformly tested at the end of four weeks. That’s why everybody is recommending booster for Covaxin at the end of 28 days. Theoretically, if there is enough response that lasted for four weeks, maybe it will last up to the fifth week too. But we don’t know that since there is no data,” Dr Vineeta Bal from the Indian Institute of Science Education and Research told The Times of India.

In case I miss the government stipulated time, should I take the first dose again and follow it with a booster shot?

Dr NK Arora, member of the National Committee on Adverse Events Following Immunisation, said recipients need not repeat the vaccine schedule due to delayed second dose. However, he stresses that the second shot must be taken as soon as one can get it.

Speaking to The Times of India, Dr Arora said:

“We know there are many single-dosers whose second shots have been delayed. They need not be worried. Even if gap between two doses increases to 8-10 weeks, in case of any of the two vaccines, beneficiaries can take the second shot and it will still be effective. There is no need to repeat the vaccine schedule due to a delayed second dose.”

I got a slot for my second dose but was infected with COVID-19. When should I take my second shot?

You should take your second shot three months after complete recovery from COVID-19, as per the latest guidelines issued by the health ministry.

I caught COVID-19 after first dose and took eight weeks to recover. Should I still take the second dose of Covaxin?

Yes, you should. A person who has recovered from coronavirus should complete their vaccination schedule after their recovery period. This holds true for both vaccines.

If I do not get a slot for Covishield for second dose, should I get Covaxin?

No. As of now, experts advise that you take the same vaccine for first and second dose.