You're Far Less Likely to Spread Covid-19 If You Get the Vaccine, Real-World Data Suggests
Real-world data is offering hope that mRNA vaccines are highly effective at limiting infection and presumably transmission of the coronavirus, in addition to their already-known ability to prevent symptoms of covid-19. The findings, based on research from Israel and elsewhere, are good news for containing the pandemic sooner rather than later.
A study published in the Lancet last week looked at healthcare workers at Israel’s Sheba Medical Center. The study compared rates of covid-19—both with symptoms and without—among workers who received the Pfizer/BioNTech vaccine or not. As other research has shown, people were significantly less likely to contract covid-19 after receiving the first of two scheduled doses.
Within two to three weeks following the first dose, the risk of having symptomatic covid-19 was reduced by 85%. Importantly, the risk of covid-19 in general, including asymptomatic infection, in which a person has the virus but doesn’t feel sick, was also reduced by 75% in that same period, based on regular PCR testing. That’s crucial, because even people with silent infections can still transmit the virus to another person. But if a vaccine is largely preventing people from being sick and from carrying enough of the virus to test positive, that means it’s also lowering the risk of virus transmission from a vaccinated person to others.