The following article is a review article written by Keir Lewis. The views and opinions expressed in this article are those of the author and do not necessarily reflect the official position of the technology network. The world is in the middle of the largest vaccination program in history-an incredible feat achieved through a combination of cutting-cutting-edge science, international cooperation, innovation and highly complex logistics. So far, at least 199 countries have initiated vaccination programs. Some people are moving forward—for example, in Canada, nearly 65% of the population has received at least one dose of the vaccine, while in the UK, the proportion is close to 62%. Considering that the vaccination program started only seven months ago, this is a remarkable achievement and a big step towards returning to normal life. So, does this mean that most adult populations in these countries are exposed to SARS-CoV-2 (the virus) and therefore will not suffer from COVID-19 (the disease) and its potentially life-threatening symptoms? Well, not exactly. First of all, it should be noted that there are two types of immunity-natural immunity, that is, people produce antibodies after being infected with a virus; and vaccine-derived immunity, that is, people who produce antibodies after being vaccinated. The virus can last up to eight months. The problem is that we don’t know how many people infected with the virus have developed natural immunity. We don’t even know how many people have been infected with this virus-firstly because not all people with symptoms will be tested, and secondly because many people may be infected without showing any symptoms. In addition, not everyone who has been tested has recorded their results. As for vaccine-derived immunity, scientists don’t know how long this situation will last because they are still figuring out how our body is immune to SARS-CoV-2. Vaccine developers Pfizer, Oxford-AstraZeneca, and Moderna have conducted studies that show that their vaccines are still effective six months after the second vaccination. They are currently studying whether booster injections are needed this winter or later.
Post time: Jul-09-2021