Every day we come to know about new variants and dreadful news about virus mutating more than our preparation to fight it. Hence many governments and pharmaceutical companies are contemplating the requirement of the Covid Booster shot so that more variants are covered. At the same time, WHO and health authorities are saying it is too early to confirm the requirement of such a vaccine shot. Various studies are going on in this regard. Let us understand the basics of the study and the outcome till now.
How our immunity works
Our immune system has a two-stage response to any antigen attack, namely humoral immunity and cellular immunity. Humoral immunity is anti-body mediated immunity. With assistance from helper T-cells, B-cells will differentiate into plasma cells to produce antibodies against a specific antigen. Cellular immunity on the other hand occurs inside infected cells and is mediated by T lymphocytes.
When a person gets infected or gets vaccinated, our humoral immune system comes into action and produces the B-cells. These B-cells have receptors on their surface that bind to those pathogens. These memory B-cells remain with us even after the infection is cured or once vaccinated. So if the same antigen attacks us, the immune system remembers the antigen and quickly comes into response.
Why take the vaccine if had Covid-19 infection
We need to understand that Covid-19 is different than few other infections in this immunity lasts for a long time. This is so because of mainly two reasons. Firstly, the response the body showed in developing the memory B-cells. This is independent of the severity of the infection you had. Hence a mild symptom case can have a higher number of antibodies than a severe case. Secondly, the variants are making the antibodies less useful because the body’s response to the antigen is more specific.
There have been cases of re-infection. Such cases may not be too many but are a challenge to achieve herd immunity. This is because if a person can get infected again, it means that the individual can spread the infection again. Hence we can never reach a safe area.
The vaccines developed especially mRNA-based produce antibodies which are different than those produced when you are infected. The measurable response in terms of antibodies, humoral and cellular immunity of both is different.
Need of booster shots
Many studies are happening worldwide to find out the response of the human immune system in many different cases. Let us understand case by case
Case 1: You never got infected. However, you have taken two doses as per the protocol. In such a scenario, you will require a booster dose. This is simply to ensure that you have enough strength in your immune system to respond quickly. Also, future booster shots might cover more variants.
Case 2: You got infected and then you took your regular vaccination shots as per protocol. In these cases, a booster shot may not be required. However, to ascertain the fact a small blood test might be required to gauge the strength of the immune system.
Case 3: You took the vaccine as per protocol but were infected either between two doses or after completing the protocol. This case is very similar to case 2. Hence one may not require a booster shot.
Do not shy away from vaccination
It is believed that for those who got infected, their antibodies may last up to a year in good strength. However, due to the mutating virus, there are chances of reinfection. Completing vaccination protocol remains important as it can significantly boost immunity. Infected and vaccinated individuals may avoid booster shots as the combined response is powerful enough to cover a broader group. However, before you take such a call, it is important to discuss with your doctor and undergo any tests as recommended. Also, those who didn’t get infected must take a booster shot as and when it comes.