Concerns about rare but life-threatening blood clots have limited the use of J&J’s Covid-19 vaccine – once touted as the only one-shot option in the mix – as the FDA has discontinued it except in certain circumstances. Still, there is some good news for those who received it: A single booster dose of mRNA vaccine for recipients of a single priming dose of Ad26.COV2.S (the J&J vaccine) provided protection equivalent to that of a three mRNA vaccine doses came close regime.
That’s according to a new analysis by the CDC that examined the effectiveness of four vaccination schedules during a period when Omicron was the predominant circulating variant.
They were a single priming dose of Ad26.COV2.S; a single priming dose of Ad26.COV2.S plus a booster dose of Ad26.COV2.S (Ad26.COV2.S/Ad26.COV2.S); a single loading dose of Ad26.COV2.S plus a booster dose of mRNA vaccine (Ad26.COV2.S/mRNA); and two priming doses of mRNA vaccine plus one booster dose of mRNA vaccine (mRNA/mRNA/mRNA)
The scientists then examined test data from more than 500,000 tests to determine the relative effectiveness of these therapies. As they wrote in a correspondence letter New England Journal of Medicine:
Our results indicate that all regimens containing a booster dose provided protection against symptomatic Omicron infection compared to no vaccination (95% confidence intervals did not include 0), although vaccine efficacy for the booster dose regimens was was highest for an mRNA vaccine and was lowest for the homologous Ad26.COV2.S/Ad26.COV2.S regimen.
The results “support the current recommendation of a booster dose of the mRNA vaccine at least 2 months after the primary series with a single dose of Ad26.COV2.S or at least 4 months after an Ad26.COV2.S booster dose,” the scientists added.
The White House unveils a new distribution model for Pfizer’s Paxlovid
The Biden administration has launched its first test-to-treat site as part of a campaign to get more Paxlovid, Pfizer’s oral antiviral drug, into the hands of patients.
While patients currently must obtain a prescription from a healthcare provider before they can pick up a treatment with the drug, anyone who attends the Rhode Island clinic can be evaluated by a medical provider and, if prescribed, can take their Paxlovid with them for a trial.
The deal announcement comes as the use of Paxlovid tips in the US signals not only rising case numbers, but also a greater awareness of how to access them.