According to researchers at the University of Yale, Moderna and Pfizer-BioNTech vaccines are the most commonly used vaccines against coronavirus. These vaccines are quite effective in combating multiple variants of SARS-CoV-2, that is, the virus that causes COVID-19. These findings were recently published in the noted medical journal Nature. Moreover, it was found that following vaccination, people infected with coronavirus showed an immune response that was more robust to all variants of coronavirus. The recent Delta variant of the virus has been reported in vaccinated people, raising doubts about the efficacy of the vaccine.
The research study found that vaccines helped the immune system fight back effectively against even new variants of the infection by inducing the production of a large number of antibodies against new variants, including the Delta. Moreover, the authors of the study urged individuals to take two doses of the vaccine. Furthermore, individuals were also requested to take booster shots to combat variants, such as Delta of the virus. The study was conducted on 40 healthcare workers from November 2020 to January 2021. This study included subjects who had not been vaccinated at the start of the study. During the course of the study, several groups of participants received two doses of the Moderna or Pfizer-BioNTech mRNA vaccines.
The blood samples of the participants were exposed to 16 different variants of SARS-COV-2 by researchers. The variants included the most powerful Delta variant, which is extensively circulating in the United States. Then, they measured the response of antibodies and T cells to all the variants. It must be noted that none of the participants were infected with the virus. In all the blood samples, the response of the immune cells was enhanced. Nevertheless, the intensity of the immune cell response depended on the variant and the participant. A robust response was noted in individuals exposed to Delta variant.
Breakthrough cases were those that showed an infection develop despite being vaccinated. These cases were caused by Delta variant but it does not mean that the vaccines failed in providing protection against coronavirus. Instead, it means that Delta variant was so infectious that it overcame the immune defense system of patient’s body. However, patients who had been vaccinated before contracting the infection showed a lesser severity in the infection. Compared to other variants, Delta is the most infectious one because it is highly transmissible. The participants were divided into groups: those who had been vaccinated before being infected with COVID-19 and those who had not been vaccinated.
The participants who had been infected before being vaccinated showed an immune response that was more robust than the participants who were not infected with the virus. The researchers were of the view that the robust immune response was like a first dose of the vaccine, recovering participants from their initial infection. The vaccinated participants should have received a booster shot, which would have increased the number of antibodies and T cells that offer protection against infections.