The Center for Disease Control and Prevention (CDC) has corrected statements made by its director Rochelle Walensky, who had previously stated that vaccinated people cannot get or transmit the virus.
Recently, it became known that a patient fully vaccinated against COVID-19 contracted the disease, a situation that generated doubts about the effectiveness of the immunization.
“It is possible that some people who are fully vaccinated may contract Covid-19. There is no clear evidence whether they can transmit the virus to others. We continue to evaluate the evidence,” a CDC spokesperson told The New York Times.
“Clearly, some vaccinated people do get infected,” said University of Pittsburgh Vaccine Research Center director Paul Duprex.
“We’re stopping symptoms, we’re keeping people out of hospitals. But we’re not making them completely resistant to an infection,” he added.
What is certain is that so far is that vaccine reduces the risks of the infection being serious or fatal. Somehow the vaccine reduces the symptoms and would be saving the lives of people already immunized; this does not mean that there is no margin of error, or that there are no exceptions.
Something similar happened with chickenpox: its vaccine does not prevent people from catching the disease, but it reduces the symptoms and reduces the severity.
The Centers for Disease Control said Monday that the vaccine prevented 90% of infections in a real-world study of health care workers, first responders and other essential workers.
The study was conducted in 3,950 health care workers, emergency personnel and others at high risk of infection and showed that the vast majority of people who received the vaccine remained virus-free after two weeks.
Also a clinical trial by Pfizer and BioNTech revealed that 77 people had a coronavirus infection after receiving the vaccine, compared to 850 people who received a placebo.
The study also shows that the vaccine provides protection for at least six months after the second dose and confirms that it also protects against COVID-19 variants.
Although antibodies should kill the virus in the body of the vaccinated person, experts point out that there may still be some of the virus in the nose that could infect other people.
Adolescents can also be vaccinated
Pfizer’s coronavirus vaccine is 100% effective in preventing infection in adolescents aged 12 to 15, the drugmaker said on Wednesday.
The results of the clinical trial suggest that the vaccine is more effective for that age group than for the same adults, and it said it has similar mild side effects. The trial consisted of 2,300 adolescents from across the United States.
No adolescents who received the vaccine contracted COVID-19, while 18 adolescents in the placebo group did, Pfizer said in its announcement .
Pfizer added that it will seek permission from the Food and Drug Administration and the European Medicines Agency to license the vaccine for adolescents.
How long does it take for vaccines to take effect?
Protection from the Pfizer/BioNTech vaccine is obtained 7 days after receiving the second dose. Moderna’s vaccine takes 14 days to take full effect from the time a person receives the second dose. AstraZeneca‘s vaccine takes effect 28 days after the second dose.
With the J&J vaccine, protection against the disease begins about two weeks after vaccination.
According to the CDC as of Thursday, April 1, more than 99 million people have received at least one dose of the vaccine, and 56 million more, or 17% of the population, have received both doses.