Explained: Is There Any Need For COVID-19 Vaccine Booster Shots?
Scientists are arguing against Covid-19 booster shots for the entire population and emphasising the need for achieving vaccine equity.
A group of researchers from the US Food and Drug Administration, the World Health Organisation, and universities spread across the world believe that we are still not at that stage of the pandemic where COVID-19 vaccine booster shots are required. They have written a brief in the medical journal Lancet arguing against booster shots for the entire adult population.
The Biden administration in the US intends to start booster shots for the Pfizer vaccine from September 20 for those who are immunocompromised and are older than 65. They have plans to give booster shots to adults if the breakthrough infections by the Delta variant increase. The US is reporting over 1,500 deaths daily but predominantly among the unvaccinated. Israel, meanwhile, has started booster shots for its adult population after the country saw a surge in breakthrough infections post full vaccination.
This is not the first time that Dr. Soumya Swaminathan, Chief Scientist of WHO, and Mike Ryan, the executive director of the WHO Health Emergencies Program, are voicing against the need of booster shots. Earlier, in many interviews to media publications, both these researchers have emphasised the need of vaccinating those who have received no doses over giving booster shots to people who already have some immunity against the SARS-CoV-2.
Is There A Need For COVID-19 Vaccine Booster?
In the medical journal Lancet, a viewpoint titled "Considerations in boosting COVID-19 vaccine immune responses" notes that there is a need for achieving vaccine equity wherein those who have no access to even one dose of the vaccine should be able to get partially vaccinated. All the authors also believe that there is no substantial evidence suggesting the need for booster shots for the entire adult proportion. Currently, we are not even sure of the time it takes for antibody responses generated by the available vaccines to wane.
To further drive their point home against the conversation around booster shots, the researchers write that the available vaccines are all significantly effective against the original virus and even the variants that have subsequently emerged. Even though the impact of the vaccines is lesser on the delta variant as compared to an alpha variant, the vaccines even protect from causing severe disease that the delta variant is capable of.
The current variants do not escape from being targeted by the intended immune responses by the available vaccines. The need for boosters would arise if any new variant arises that is not identified by the vaccines. Variants will only arise if the existing variants are not acted upon, the scientists add.
The researchers agree that there has been an increase in the number of breakthrough infections, but they consider it to be an inevitable part of vaccine science. The main motive of the vaccines, they write is to prevent severe disease, hospitalisation, and deaths. The vaccines, so far, do not protect against transmission or mild disease.
So, What Should Be The Focus In Covid-19 Vaccination?
BOOM spoke to virologist Shahid Jameel, director of the Trivedi School of Biosciences, Ashoka University to understand his take on COVID-19 vaccine booster shots.
"Science does not support booster shots. At least not yet. All Covid vaccines are designed to prevent severe disease and mortality and they are doing this well despite the highly infectious Delta variant. Our focus should remain on vaccinating as many people as possible instead of wasting doses on boosters at this time, " Jameel stated.
According to Our World In Data, only 1.9 percent of people in low-income countries have received at least one dose from the 5.76 billion doses administered globally. While UAE is leading with at least 90 percent of its population having received at least one dose, countries such as Tanzania and Nigeria have only covered 0.57 and 1.9 percent of their population with at least one vaccine dose, respectively.
BOOM also spoke to Dr. Prabhat Jha, epidemiologist, founding director of the Centre for Global Health Research in Toronto and professor of disease control at the University of Toronto for the need of booster doses.
"Booster doses in India are not a good idea. The challenge are the unvaccinated in India- they are the source of new variants. The vaccines work well against serious disease well over time. India lags behind on coverage of vaccines. The singular focus should be to ensure all adult Indians have the 2 doses of the vaccines.
Boosters are a western distraction and might well be harmful to public health if they reduce coverage with 2 doses or persuade people that the vaccines don't work (They do!), " said Dr. Jha in an emailed response.
Do Vaccine Booster Shots Provide More Immunity?
Antibody response is not the only kind of immunity offered by all the vaccines, the authors note in the Lancet report. Even if the antibody wanes after a certain period of time, there is cell-mediated immunity, given by T and B cells to act against the virus.
While highlighting that the studies promoting booster shots are observational in nature, the scientists also pinpoint that neither do boosters so far offer additional immunity nor is there any evidence suggesting that they protect from possible side effects. There are no findings on the intensity of plausible side effects such as myocarditis associated to the second dose of mRNA vaccines and Guillain Barre syndrome associated with the adenoviral vaccines that could arise post the third dose.
The authors concluded by stating that the message that boosting might be needed could create vaccine hesitancy among people and undermine the primary message that vaccines are safe and effective. With several anti-vaccination voices arising across the world, without any robust data or analysis supporting this need for booster shots, it would be too early to promote their use.