A single dose of vaccine enhances protection for people previously infected with COVID-19

Single doses of the vaccine enhance protection against SARS-CoV-2 coronavirus mutants, but studies have found only those with previous COVID-19.

People who have never been infected and have only been vaccinated once may have an inadequate immune response to the variant of concern.

Survey results published today in the journal Science We examined the immune response of British healthcare professionals at Pfizer / BioNTech Vaccine after the first dose of the Pfizer / BioNTech vaccine, led by researchers at Imperial College London, Queen Mary University of London, and University College London.

They found that people who had previously had a mild or asymptomatic infection had significantly enhanced protection against Kent and South African variants after a single dose of the mRNA vaccine. Patients who have not previously taken COVID-19 have a weak immune response after the first dose and may remain at risk of mutation.

Professor Rosemary Boyton, a professor of immunology and respiratory medicine at Imperial College London, who led the study, said: , It is not completely protected from the circulating mutant strains of concern. This study emphasizes the importance of initiating a second dose of the vaccine to protect the population. “

Blood samples were analyzed for the presence and level of immunity to the original strain of SARS-CoV-2 and the concerns of Kent (B.1.1.7) and South Africa (B.1.351) variants. In addition to antibodies, Y-shaped proteins that attach to viruses and help block or neutralize threats, researchers have also focused on two types of white blood cells.And T cells, Helps B cells remember and recognizes and destroys coronavirus-infected cells.

They should be able to provide effective protection against SARS-CoV-2, Kent and South African variants in relation to previous infection-boosted T cells, B cells, and neutralizing antibody responses after the first dose of the vaccine. I found.

However, in people who have not been previously infected with SARS-CoV-2, a single dose of the vaccine can be used. Neutralizing antibody It may remain vulnerable to infection against SARS-CoV-2 and its variants, emphasizing the importance of a second vaccination.

The team considered two variants of concern, but the findings also apply to other variants in circulation, such as those in Brazil (P.1) and India (B.1.617 and B.1.618). I think there is a possibility.

It remains unclear exactly how much protection T cells provide. Interestingly, the mutations in the Kent and South African mutants here resulted in T cell immunity. It may not decrease, enhance, or change compared to the original strain, depending on the genetic differences of the person.

Our data show that natural infections alone may not provide sufficient immunity to mutants. It is probably the case that a previously infected person is vaccinated once and boosted. As new variants continue to emerge, it is important to quickly track the global deployment of vaccines, reduce viral infections and eliminate opportunities for new variants to emerge. “

Professor Rosemary Boyton, Professor of Immunology and Respiratory Medicine, Imperial College London

Professor Danny Altmann, a professor of immunology at the Imperial University, commented: The UK received only one vaccination. We know that this provides significant protection against the original virus, but our data suggest that this makes people more susceptible to variants of concern.

Professor Áine McKnight of Queen Mary University of London said: Shows a more modest immune response. You need to make sure that your global vaccination program is fully implemented. Current events in India painfully reveal the cost of complacency. “

“These results represent the best collaborative science among hospitals, universities and public institutions, and are important timely to inform policy and strategy,” said James Moon, a professor at University College London and Baht. It provides good results. “

The study was conducted in collaboration with researchers at Barts Health NHS Trust, Public Health England, Royal Free Hospital NHS Trust, University College London, and the University of Nottingham.

This study was supported by funding from the UKRI Medical Research Council, Rosetrees Trust, and Barts Charity.