A single shot of either the Pfizer or AstraZeneca vaccine provides around 60 percent protection against infection from Covid-19, in adults aged 65 years and above, according to a new study published in The Lancet. The study, led by researchers from University College London in the UK, showed that the protective effect of a single dose of the vaccine is evident from as early as four weeks to at least seven weeks after vaccination, which may support an extension of over three weeks interval.
Meanwhile, Madhumita Shrotri and Laura Shallcross, from the UCL Institute of Health Informatics said, "However, even beyond four weeks, a single vaccine dose does not eliminate infection risk, highlighting the continued importance of non-pharmaceutical measures to control transmission within long-term care facilities. The study will be critical to informing policy decisions regarding revaccination schedules in this vulnerable population and the disease control measures needed in the short, medium, and long term to protect long-term care facilities from future waves of SARS-CoV-2 infection."
US scientists have developed a universal vaccine that protected rats not just against COVID-19 but also other coronaviruses. The vaccine has triggered the immune system to fight off a dangerous variant. This vaccine is going through its final stages. Once this vaccine is ready, then we will have a powerful weapon to fight such epidemics in the future.
The trial of this vaccine is currently being undergoing on rats. When this vaccine was tested on mice, the vaccine developed many such antibodies that can counter many spike proteins. This also included variants such as B.1.351 found in South Africa.