Delayed Second Pfizer COVID-19 Shot: According to a British study released on Friday, May 14 Pfizer-BioNTech COVID-19 vaccine generates three-and-a-half times more antibody response in older people (over 80) if the second dose is delayed to 12 weeks after the first. The UK public health officials believe that this could help them in changing the approach and prioritising the rollout of the first dose of the vaccine.

The study was led by the University of Birmingham in a collaboration with Public Health England. It was supported by the UK Coronavirus Immunology Consortium and had 15 people above the age of 80 years. The study is the first direct comparison of the immune response of people of any age group who were given the second dose of Pfizer vaccine to those who got the shot at a 12-week interval.

Pfizer vaccine was originally authorised to be given after a three-week interval from the first dose, however, many countries expanded this period to a 12-week interval so that a higher percentage of the population could receive one vaccine dose quicker.

The findings of the research say that a 12-week gap in the second dose of the vaccine increases the peak SARS-CoV-2 spike specific antibody response compared to people who got their second dose in three weeks, which is believed to be an important aspect in virus neutralisation and prevention of the infection.

When the second dose is given at an interval of three weeks, it generates a higher peak in T-cell response as compared to the delayed dose. According to scientists, T-Cells may be a marker for long-term immunity against the virus. However, the authors of the study have warned against making conclusions on which dose strategy provides better protection against the virus.

According to the Public Health of England, the study was supportive of the Government of Britain’s approach of delaying the second dose of the vaccination to prioritise a large scale rollout of the first dose.