People wait in line for coronavirus (COVID-19) vaccinations at Martin Luther King Jr. Community Hospital in Willowbrook, Los Angeles, California, February 25, 2021.
Lucy Nicholson
The US is “nowhere near” in achieving herd immunity to Covid, and more transmissible variants mean even more people will need to be vaccinated to achieve it, a CDC scientist said Friday.
Herd immunity occurs when enough people in a given community have antibodies to a specific disease, either through vaccination or previous exposure to the virus. That makes it difficult to spread from person to person and protects even people who don’t have immunity.
“We currently know that the majority of the US population is not immune to SARS-CoV-2 and variants may increase this portion of the population that is not immune,” said Adam MacNeil, an epidemiologist at the Centers for Disease. Control and Prevention.
Reaching the herd immunity threshold while fighting new, more contagious strains of viruses will require a higher proportion of the population to be vaccinated, MacNeil said at a Food and Drug Administration meeting in which Johnson & Johnson’s application for his Covid -19 emergency vaccine approval was assessed. use.
Scientists don’t believe immunity lasts forever. It weakens over time, and that could worsen the outbreak as previously protected people become vulnerable to infection, MacNeil said.
MacNeil’s comments come a week after a Wall Street Journal opinion piece claimed the US will achieve immunity to herds in April.
While Covid variants have been shown to reduce the effectiveness of a Covid vaccine to protect against infection, vaccines have been shown to be effective in preventing serious illness and hospitalization against the more contagious strains.
Scaled-up vaccination would significantly slow the current trajectory of a highly contagious Covid variant first identified in the UK as the dominant strain of virus in the US by March, MacNeil said.
MacNeil said increased vaccination will be critical for the country to catch up with the benchmark.
“The vaccination has started and hopefully this will bring us closer to filling the herd’s immune gap.”