Democratic Rep. Stephen Lynch of Massachusetts, who has been vaccinated for Covid-19, tested positive for the virus on Friday afternoon and remains asymptomatic, according to his spokeswoman, the CNN reported.
"This afternoon U.S. Representative Stephen F. Lynch received a positive test result for COVID-19 after a staff member in the Congressman's Boston office had tested positive earlier in the week," Lynch's spokeswoman Molly Rose Tarpey said in a statement Friday.
The Massachusetts Democrat plans to isolate and will vote by proxy in Congress over the coming week, according to Tarpey.
The congressman had received a second dose of the Pfizer vaccine and had tested negative for Covid-19 before attending President Joe Biden's inauguration on January 20, Tarpey said. But she did not specify when Lynch received each dose of the vaccine.
Covid-19 vaccines prevent illness, but do not necessarily prevent infection. If someone tests positive and doesn't get sick, the vaccine has worked as intended. If someone tests positive within a few weeks of receiving the second dose, it may be because the vaccine hasn't yet fully kicked in.
The US Centers for Disease Control and Prevention says building immunity to Covid-19 "typically takes a few weeks" after vaccination.
Lynch is the latest member of Congress to test positive for the virus in recent months, as the Covid-19 pandemic continues to rage across the country.
A few members of Congress and more than three dozen Capitol Police officers tested positive for Covid-19 after the January 6 insurrection at the US Capitol. Experts consider the riot, which broke out as Congress was certifying the 2020 presidential election results, a likely super spreader event.
Three Democrats earlier this month said they tested positive for Covid-19 after sheltering in place that day with other members of Congress who chose not to wear masks.