Questions surrounding immunization & transmission
Even though Americans could start getting vaccinated in days, experts say people who get the shot will still need to wear masks and practice social distancing until scientists can answer a key question.
By: Derek Staahl
SAN DIEGO (KGTV) — Even though Americans could start getting vaccinated in days, experts say people who get the shot will still need to wear masks and practice social distancing until scientists can answer a key question: whether immunized people can continue to spread COVID-19.
The clinical trials by Pfizer and Moderna showed the two vaccines were about 95 percent effective, but what that really means is they were 95 percent effective at preventing COVID-19 symptoms.
The trials did not measure whether vaccinated volunteers got infected without showing symptoms.
That means “it is possible and conceivable” that immunized individuals could still be silent spreaders, said Dr. Christian Ramers of Family Health Centers of San Diego. “You’re not going to get sick, but you still get an asymptomatic case, pass it on to your grandmother and kill her.”
Both the Pfizer and Moderna vaccines are injected into the arm muscle to stimulate production of antibodies. From there, the antibodies can quickly get to the lungs to fend off severe infection. But experts say the antibodies may have less access to the nose and throat, the primary entry points for the virus.
Some studies have suggested that people without symptoms can still have high enough levels of coronavirus in their nose to infect other people.