In the United States and Canada, there have been several cases of contamination after vaccination. A delay seems to be necessary to offer effective protection, according to several sources.
A certain time for optimal protection?
Two episodes of reinfection occurred in the United States and Canada after an injection of the Pfizer-BioNTech vaccine. According to ABC news, a symptomatic man, who is a nurse in San Diego, California, tested positive after a vaccination the previous week. In Canada, 66 residents and 20 employees of an nursing home were infected a few days after vaccination, according to the Canadian press.
Jacques Girard, medical assistant to the director of public health in Quebec, told Radio Canada that “ until the vaccination allows us to have the benefits in terms of protection, there is a delay of about two weeks for the rise of antibodies “. Nathan Peiffer-Smadja, infectious disease specialist at Bichat hospital, indicates that “ It is quite standard that the efficacy of the vaccination does not immediately intervene when the product has been injected, there is no surprise in this “.
Within 2 weeks
” The vaccine offers some protection against Covid-19 within about 10 days of the first dose Said the Pfizer group, indicating that protection is more about the onset of symptoms than the infection. Nathan Peiffer-Smadja specifies that “ the vaccine prevents the disease from being generated. It is likely to also limit the risk of infection, although there is not yet definitive proof. “. The US Food and Drug Administration agrees with the delay.
To be effective, Pfizer recommends 2 administrations, 3 weeks apart, because the protection ” is greatly enhanced after the second dose, confirming the need for a two-dose series of vaccines “. ” We believe the first dose gives you around 50%, and you need this second dose to get to 95% »Developed infectious disease specialist Christian Ramers.
