Coronavirus Vaccine: Will COVID vaccine be a two-dose shot or will need a booster shot every year? Here’s what we know

Getting a COVID shot does not ensure complete protection against the new strain of coronavirus. The vaccination simply protects us from developing severe symptoms and that too for a fixed time. None of the vaccinations available at this point are 100 per cent effective in real-world conditions. So, after a set period, you may need another dose to protect yourself from getting infected. As per experts in the field of medical science, getting the shot may become a regular event till the time a new vaccine is introduced.

The greatest challenge at this time is the effectiveness of the current vaccine against the mutation of the virus. A vaccine's effectiveness and efficacy may not be the same. A high efficacy rate does not always mean a high level of effectiveness in the real world and vice versa. Most of the time, the effectiveness of the vaccine varies due to variables happening in the real world. Secondly, the strain of coronavirus is continuously mutating and the same vaccine may not be effective on all the mutant variants.

According to Pfizer CEO Albert Bourla, the COVID vaccine available right now may not offer the kind of protection that keeps you safe forever. In an interview with an American broadcast television network, he clarified that an individual may need to take Pfizer COVID shots every year to stay safe. Pfizer vaccine was proven to be 95 per cent in the clinical trial, but in the real world, things work differently. Bourla revealed that they are conducting trials for a potential third dose of the Pfizer vaccine to make the current vaccine more effective against mutated versions of the virus. He pointed out that just like flu shot, one needs to get the Pfizer COVID shot annually to deal with the changing nature of the virus.

Even in the case of the Moderna vaccine, one may need to get the shot regularly to tone down the effects of the virus. Moderna CEO Stéphane Bancel in January had also stated that we need to learn to live with the virus as it is not going anywhere. He stated that the virus would become endemic and affect people at low levels, rarely causing severe illness. He also made it clear that one may need to take a booster shot after every one or two years just like is the case with many other vaccines.

In the clinical trial, AstraZeneca's Covishield vaccine has 81.3 per cent, while Covaxin has 81 per cent rate of efficacy (as per the Lancet). Both these vaccines are being provided in India to provide immunity against the virus. India has launched the third phase of vaccination drive with everyone above the age of 45 now eligible for the jab. But till now it has not been confirmed how long these vaccines can protect against the virus. The experts in the field are yet to be established if both the vaccines can provide life-long immunity to a person.

As per a study carried out by the People’s Vaccine Alliance, a coalition of international organizations that includes Amnesty International, UNAIDS, and Oxfam, about two-thirds of scientists surveyed agree that the current vaccines will need to be modified within a year.

Of the 77 epidemiologists, virologists, and infectious disease specialists surveyed by the organisation from 28 countries, two-thirds felt the need to upgrade the vaccine within a year, while one-third believed that it needs to be done as soon as nine months from now. As per these scientists, the slow vaccine coverage in some countries may lead to mutation of the virus, which may not be controlled by the current shot.