Researchers urge public to get second COVID-19 vaccine dose after study finds single dose of Pfizer vaccine insufficient to protect against variants
Researchers in Britain have found that one dose of the Pfizer-BioNTech vaccine provides insufficient protection against new variants of the COVID-19 virus and urged public-health officials to be vigilant about ensuring that people receive a second injection.
The study “is basically showing that if you’ve had prior COVID-19, and then you’ve had a single dose vaccine, you are really in a different league in terms of your immune response,” said Rosemary Boyton, a professor of immunology and respiratory medicine at Imperial College who co-authored the study. “It’s almost like the infection has acted as a prime and the first dose has acted as a boost.”
However, the group of volunteers who had not been infected showed a much weaker immune response to the variants after one dose. The study showed that their level of neutralizing antibodies was 11- to 25-fold lower against the B. 1.1.7 variant compared with the original version of the virus, “resulting in the majority of individuals falling below the protective threshold.”
Researchers in the UK and United States have demonstrated the efficacy of one dose of either the Pfizer-BioNTech or Oxford-AstraZeneca vaccine against infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a real-world community setting in the UK.
Almost all adults in Serrana, Brazil, got COVID-19 shots. That may help answer questions about how well vaccines will work to end the pandemic.
A clinical trial is one thing. The real world is another.
During the project’s vaccination from mid-February to mid-April, six immunized people died from COVID-19, according to the state government of São Paulo. Of those, five had received only one dose and the other person showed symptoms shortly after receiving the second dose, which leads researchers to believe the patient was already infected at the time of the second shot. Among the unvaccinated there were 14 deaths.
In the beginning of May, none of the six infirmary beds at Serrana’s Santa Casa Hospital and the city’s Basic Healthcare Unit are occupied, and the waiting line for beds both in infirmaries and intensive care units has zeroed. As of May 3, there is one Serrana resident in an infirmary and nine patients in an ICU, according to the Serrana Health Secretariat.