The Omicron variant of the coronavirus has been so contagious that it could have appeared a foregone conclusion that if one individual in a family grew to become ailing, different folks residing there would catch the virus, too.
However that seems to be much less sure: A small research of households by the Facilities for Illness Management and Prevention launched on Friday discovered that when the primary individual contaminated wore a masks and stayed in a separate room no less than a part of the time, the danger of different family members contracting the virus grew to become markedly decrease.
Vaccinated individuals who grew to become contaminated have been additionally significantly much less seemingly than unvaccinated folks to unfold the virus to different members of their households.
Nonetheless, the research highlighted simply how aggressively the Omicron variant had unfold inside a house, particularly amongst folks residing with youngsters beneath 5 who examined optimistic. These youngsters, who are usually not but eligible for vaccines and sometimes have to be in nearer contact with their mother and father or family, unfold the virus to 72 % of family contacts recognized within the research — the very best charge of any age group, the C.D.C. stated.
“These findings additional spotlight younger youngsters’s potential contribution to family transmission,” C.D.C. scientists wrote within the report.
Federal regulators are ready for information on how effectively three doses of the Pfizer-BioNTech coronavirus vaccine work in youngsters beneath 5 earlier than deciding whether or not to authorize the vaccine for that age group.
The C.D.C. research was based mostly on 183 households throughout 4 states the place somebody grew to become contaminated with the Omicron variant from November to early February. After interviewing members of the households about their vaccination and an infection histories, any precautionary measures within the house and whether or not they had examined optimistic or develop into ailing, C.D.C. scientists decided that the variant had unfold in roughly two-thirds of the households they recognized.
However when the primary contaminated individual was totally vaccinated, solely about 44 % of family members developed Covid, in contrast with 64 % when the contaminated individual was unvaccinated, the research stated.
And when the unique contaminated family member stayed in a room alone no less than a number of the time, solely 41 % of different members of the family grew to become contaminated, in contrast with 68 % in conditions with out isolation. Masking by the contaminated individual helped, too, decreasing the chance of transmission to 40 % from 69 %.
Figuring out the exact threat of the virus spreading in a house was troublesome, the research’s authors famous. They excluded conditions the place it was unclear who had first developed Covid, and didn’t do the genetic sequencing essential to know for sure that individuals had caught the virus from the contaminated individual of their house reasonably than at different gatherings.