As India gears up to battle the third wave of the COVID-19 pandemic and the vaccination drive intensifies to innoculate the entire country by the end of the year, questions are being asked will we need a booster shot/dose for the COVID-19 vaccine as well in the future? The query emerges from the speculations that it might take years to wipe out the coronavirus pandemic completely. The mutations in the SARS COV-2 virus leading to various variants across the globe are only adding to the worries of the people.
The need for booster shots depends on the answer to the most pertinent question: how long do the current vaccines protect human beings from the coronavirus? We don’t know that yet. The COVID vaccines are new and the trials to study the longevity of their protection has just begun. Though many believe that the vaccines may shield people from the coronavirus for up to a year, but that too is not yet established with thorough research. We also don’t know if these vaccines will continue to beat the emerging variants of the virus.
What is a booster dose/shot? Why do we need it?
In reality, we don’t need a booster shot/dose in all cases. For example, one measles shot is enough to protect human beings from the disease for their entire life, while a tetanus vaccine loses its steam over the years requiring a booster shot once a decade. But in the case of flu, we need a vaccine every year to protect ourselves from its virus.
Thus the requirement for the booster dose depends entirely on the pathogens and how they affect our immunity system. It may depend on the mutative capability of the virus. Because the faster the virus may mutate, the greater could be the need to update the vaccine to protect us.
How variants affect the protection from vaccines?
With the emergence of various COVID-19 variants, studies with the help of genome sequencing are underway in many countries to know if the vaccines continue to be effective on the new mutants. And some of the studies are quite revealing.
For example, the analyses of Public Health England (PHE) in England and Scotland showed that the vaccines are less effective on the Delta variant as compared to the Alpha one. Similarly, another study in Qatar showed that the Alpha variant decreased the effectiveness of a particular vaccine to 89.5 percent while the Beta variant lowered the effectiveness to 75 percent. However, the capability of the vaccine to prevent the severity of the disease was unaffected.
Will booster dose/shot be made variant-specific?
While the research is still in progress, so far it is clear that the emergence of new variants is not necessarily posing an immediate threat to human beings, as the available vaccines are equally effective in blunting their severity. But there are chances that stronger mutants in the future may require the need for a booster dose/shot.
That’s why pharma company like Pfizer has begun working in that direction also keeping in view the requirement of a booster shot/dose of the COVID vaccine. The booster dose evidently will be specifically targeting the new variants and it will be administered to those who have already received the first two doses of the vaccine.
Research on the durability of vaccine protection
During the vaccine trials, researchers have witnessed a gradual drop in the levels of antibodies and immune cells targeting the coronavirus. But the rate is slow, which means the vaccines continue to be potent enough for a very long time. Those who received the jabs after recovering from the COVID-19 may have even greater protection from the reinfection.
So early signs are encouraging, but the research is on to find the durability of the vaccine protection. Nothing is confirmed yet, but as of now, the possibility is that a booster shot/dose may not be required for over a year or maybe years.