FAQ: Do You Need Third Booster Dose of COVID-19 Vaccine?

The question over a third vaccine dose is emerging amid the deadly new wave and the increasing number of variants.

(Photo: PTI)

Currently, the only solution to fight coronavirus around the world is with vaccination. Those who have received both the doses of the COVID vaccine have some assurance that they can protect themselves by adopting other safety measures.

But are two doses of vaccine enough to fight coronavirus? FIT breaks it down for you.

Will we need a third dose for better protection?

In India, there is a gap between two doses of the vaccine. Together, these two doses are called the ‘prime doses’ of the vaccine. Any dose given post this is called a ‘booster dose’.

On 27 May, Dr VK Paul, Chairman of the Central Government's Task Force on COVID Vaccine and Member of the NITI Aayog, said in a press conference, “Information is being collected about the need and timing of booster doses of different vaccines. If it is needed, protocols and guidelines will be made available.”

In a conversation with FIT, Virologist Dr Shahid Jameel explains: “Right now, the COVID vaccine has been tested in a two-dose trial. Further doses may be needed, but a study should be done to prove this. However, booster dose is not required so soon. Immunology also does not say that. It is of no use to take booster doses so soon.”

“The third dose does not affect the memory response or secondary response. But, after 2-5 years, it can consolidate the decreasing memory response.”

Virologist Dr Shahid Jameel to FIT

COVID is a new disease and we don’t have enough data to ascertain when the memory response degrades. We need further studies for that, he further adds.

Is there risk of infection even after vaccination?

“Among the available vaccines, no company has said there will not be any reinfection. After taking the vaccine, you will not have serious illness. This difference should be understood. Both infection and disease are different things,” Dr Jameel says.

AstraZeneca's website claims, "the results of the Phase-3 trial of the vaccine have found that the vaccine provides 100 percent protection from serious infections, hospitalizations, and deaths due to Covid-19."

However, many vaccine manufacturers in the world are saying the third dose is important.

What are vaccine companies and experts saying?

India's indigenous vaccine Covaxin has begun trials for the booster dose.

The trial is being held at the All India Institute of Medical Sciences, Delhi. In the trial, the booster dose will be taken at an interval of 6 months after taking the second dose. Therefore, this trial will be done only on those who are part of the Phase-2 trial of Covaxin.

Pfizer CEO Albert Bourla and BioNTech CEO Ugur Sahin have emphasised the potential need for a third shot within 12 months after the initial vaccination.

Moderna CEO Stephane Bancel, in an interview on 23 May, said that more people need to take a third dose as a booster shot to avoid the risk of a new variant of the virus.

“We believe that our vaccine will be effective for a comparable period, except that the arrival of variants increases the threat level. This is why we must anticipate and vaccinate all people at risk with a third dose by the end of the summer, in particular the residents of nursing homes who received their first dose at the beginning of the year.”

Stephane Bancel, Moderna CEO

US Top Infectious Disease Expert Dr Anthony Fauci has also said that the booster dose will prove to be very important in the fight against COVID.

He added that “people who have been vaccinated against coronaviruses will need a booster shot to stay safe. However, when the shot should be given is still unclear.”

Are other countries doing trials for booster dose?

According to the BBC report, the UK government is urging the working age group and people over 75 years to participate in the third dose trial to study its efficacy in defending new COVID variants.

COV-Boost vaccine trial is studying the use of seven different COVID-19 vaccines when given as a third dose.

According to the report, Professor Saul Faust, Chief Investigator at Southampton University, says that it is possible that some age groups may not need boosters and some may.

He also said, "We are not trying to say that one vaccine is better than the other. Its purpose is to find out what should be a booster campaign and which vaccine should be used.”

What are the benefits of booster shots?

Research has shown that booster shots train your body to detect and protect viruses or bacteria. Depending on the type and manufacturer of the vaccine, you may get booster shots, weeks, months or even years after your first shot.

The booster dose can activate the immune system immediately. It works on the basis of 'immunological memory' where the immune system remembers the vaccine that the body has already used. In such a situation, the booster dose activates the immune system immediately, whose effect is seen more.

In an interview to ET , Dr Giridhar R Babu, Professor and Head of Life Course Epidemiology at the Public Health Foundation of India, stated that "depending on how long the vaccine protection lasts, one needs to decide when to give the booster. But it still needs to be seen and studied whether the boosters will help in fighting the disease more effectively".

Another expert says that the third dose might play a significant role in the future, but at present, there is not enough data to support this claim. Like flu shots, one may need booster shots every year, but it is too early to make that assumption because the disease is very new in itself and the vaccine has not been exposed for even a year. We need more data and study.

(This was first published on FIT.)