According to research from University College London, 96% of 8,500 people from England and Wales developed antibodies 28 to 34 days after receiving their first dose of either Pfizer or AstraZeneca vaccine.
The research found the antibodies figure further rise to 99% within 7 and 14 days of their second shot for recipients of both vaccines, providing evidence that the vaccines provide protection against the coronavirus.
Antibody positivity rates were found to increase faster in those who received the Pfizer vaccine compared to the AstraZeneca vaccine, but by 4 weeks after the first vaccine dose antibody positivity rates were equivalent for both Pfizer and AstraZeneca vaccines.
There was also evidence that antibody levels were lower with increasing age following the first dose of vaccine. They were also lower in people with some long term health conditions including diabetes, heart disease, cancer and those currently on immunosuppressive therapies. However, following the second dose of either the AstraZeneca or the Pfizer vaccine, high antibody levels were observed for nearly all individuals including those with long term health conditions.
A total of 58 million vaccines (the vast majority being the Pfizer-BioNTech or AstraZeneca shots) have been given out in the U.K., with over 21 million people have received their second dose.
With the strong vaccination rollout, UK Covid-19 case rates have fallen and are the lowest number since the week to September 2 2020.
New data from the Office for National Statistics (ONS) figures show the COVID-19 virus was no longer the leading cause of death in March, dropping from the top spot to the third spot for the first time since October 2020.
In a separate announcement, US Centers for Disease Control and Prevention (CDC) announced Americans who are fully vaccinated can go without masks or physical distancing in many cases, even when they are indoors or in large groups.
However, the relaxation of masking does not apply to airplanes, buses, trains and other public transportation, to healthcare settings, or where state or local restrictions still require them.